JP3677144B2 - Induction motor controller - Google Patents

Description

【０００５】
（１）式においてλd ´、λq ´は、次式に示すように、夫々二次磁束鎖交数λのｄ軸成分λd 、ｑ軸成分λq を相互インダクタンスＭで除したもので、電流の次元を有する量である。
λ´＝λd ´＋ｊλq ´ …（２）
λd ´＝λd ／Ｍ …（３）
λq ´＝λq ／Ｍ …（４）
また、誘導機の発生トルクτは極対数をｎとして次式で与えられる。
τ＝ｎ（１−σ）Ｌ1 （λd ´ｉ1q−λq ´ｉ1d） …（５）
ベクトル制御では、この発生トルクτを線形化制御するので、励磁分電流ｉ1dとトルク分電流ｉ1qを常に直交させるように制御する必要があり、その直交化条件は次の２式で表される。
λd ´＝一定値 …（６）
λq ´＝０ …（７）
【０００６】
さて、上記センサレスベクトル制御においては、誘導機に印加される一次電圧指令値ｖ1d* 、ｖ1q* が、励磁分電流指令値ｉ1d* 、外部から入力される速度指令値ωr*、一次電流検出値ｉ1d、ｉ1q等を基に以下のように演算される。
ｖ1d* ＝Ｒ1 ｉ1d−σＬ1 ω1 ｉ1q＋ｖd …（８）
ｖ1q* ＝Ｒ1 ｉ1q＋σＬ1 ω1 （ｉ1d−ｉ1d* ）＋ｖq …（９）
ここで、（８）式の右辺末項は励磁分電流の偏差をＰ制御器を通してｖ1d* に帰還するためのものであり、（９）式の右辺末項はトルク分電流の偏差をＰＩ制御器を通してｖ1q* に帰還するためのものである。そして、（９）式で表されるｖ1q* を（１）式第２行左辺のｖ1qに代入し整理した後、定常状態において成立するｉ1q＝ｉ1q* の関係を適用すると、一次周波数ω1 は、トルク分電流の偏差の積分値である電圧ｅを用いて推定可能となる。
【０００７】
一方、制御器においてすべり周波数推定値ωs'は、すべり周波数ゲインｋωs を用いて次式から得られる。
ωs'＝ｋωs ｉ1q／ｉ1d* …（１０）
ｋωs ＝Ｒ2 ／Ｌ2 …（１１）
このすべり周波数推定値ωs'と前記一次周波数ω1 とから速度推定値ωr'が次式のように演算される。
ωr'＝ω1 −ωs' …（１２）
こうして得られた速度推定値ωr'と外部から与えられる速度指令値ωr*の差分である速度偏差をＰＩ制御器を通すことによりトルク分電流指令値ｉ1q* が得られる。
【０００８】
以上の制御原理の説明から分かるように、一次電圧指令値ｖ1d* 、ｖ1q* の演算には、一次抵抗Ｒ1 、一次、二次自己インダクタンスＬ1 、Ｌ2 、及び相互インダクタンスＭが、またすべり周波数推定値ωs'の演算には二次抵抗Ｒ2 と二次自己インダクタンスＬ2 が用いられている。この内一次抵抗Ｒ1 については、誘導機の駆動中に電気的に同定し、その結果を制御で用いられる一次抵抗Ｒ1'に反映する方法が考えられている。上記論文においては、誘導機の一次抵抗Ｒ1 と制御で用いられる一次抵抗Ｒ1'とのずれ（以下、一次抵抗設定誤差と称す）が、励磁分電流指令値ｉ1d* と励磁分電流検出値ｉ1dとの差分に基づいて推定できることに着目し、以下のように同定を行っている。
【０００９】
制御で用いられる一次抵抗Ｒ1'に対し、次式で示す変数ｘ1'を定義する。
ｘ1'＝Ｒ1'／Ｌ1 …（１３）
一次抵抗がずれた場合、上記ｘ1'は（１４）式のように真値ｘ1 とその微小変化分Δｘ1 とに分けられ、そのうち微小変化分Δｘ1 は励磁分電流の差分である（ｉ1d* −ｉ1d）の積分値から（１５）式に示す補正演算によって０に収束させることができる。この場合、一次自己インダクタンスＬ1 は変化しないと仮定しているので、変数ｘ1'の変動は全て一次抵抗Ｒ1'に起因すると考えている。
ｘ1'＝ｘ1 ＋Δｘ1 …（１４）
【００１０】
【式２】

【００１１】
なお、（１５）式は温度による抵抗値変化の補正が目的であるので、過渡時に励磁分電流の差分（ｉ1d* −ｉ1d）が変化しても、それによって応答しないように補正ゲインＫR を小さく（または周期Ｔを大きく）選ぶ必要がある。
以上述べた方法の他にも、励磁分電流の変動に基づいて一次抵抗設定誤差を推定した例として電学論Ｄ、１１０巻５号等があげられる。
【００１２】
次に、図１９と図２０を参照して、上記制御原理並びに一次抵抗同定原理に基づいた誘導電動機制御装置の構成について説明する。電気的構成を示す図１９において、三相交流電源１のＵ、Ｖ、Ｗ各相の母線は、三相ブリッジ接続されたダイオード等から構成される整流回路２の各相入力端子に接続され、その直流出力端子に接続された直流母線は、その母線間に平滑コンデンサ３が接続されると共に、電圧型インバータ主回路４の入力端子に接続されている。このインバータ主回路４は６個のスイッチング素子が三相ブリッジ接続されたもので、その出力端子は誘導機５のＵ、Ｖ、Ｗ各相の入力端子に接続されている。
【００１３】
座標変換器６は、誘導機５のＵ、Ｖ、Ｗ各相の巻線に流れる電流の内の２相、例えばＶ相とＷ相の電流をＣＴ等の電流検出手段により検出し、残り１相（Ｕ相）の電流をＶ相電流とＷ相電流の和の−１倍として演算した後、三相−二相変換を行う。その後、後述するセンサレスベクトル制御部９から出力される回転磁束の位相角θに基づいて回転座標変換（ｄｑ変換）を実行し、その結果一次電流の励磁分電流検出値ｉ1dとトルク分電流検出値ｉ1qとを得るようになっている。
【００１４】
座標変換器７は、励磁分電圧指令値ｖ1d* とトルク分電圧指令値ｖ1q* から、座標変換器６とは逆の座標変換を行うことにより、誘導機Ｕ、Ｖ、Ｗ各相の出力電圧指令値ｖu*、ｖv*、ｖw*を得ると、ＰＷＭ制御部８に対して出力するようになっている。而して、ＰＷＭ制御部８は、出力電圧指令値ｖu*、ｖv*、ｖw*と三角波等で構成される搬送波とからパルス幅変調されたパルス信号を生成し、図示しない駆動回路を介してインバータ主回路４の各ゲートにゲート信号を与えて誘導機５を駆動するようになっている。
【００１５】
次に、センサレスベクトル制御部９について、その制御部の構成を示すブロック図２０をも参照して説明する。
外部より与えられる励磁分電流指令値ｉ1d* は、速度推定値演算部１１と電圧指令値演算部１５に与えられると共に、励磁分電流検出値ｉ1dとの差分つまり励磁分電流偏差が演算され、その偏差は励磁分電流制御器１０に入力される。この励磁分電流制御器１０は、励磁分電流偏差に対してＰ制御を行うもので、励磁分電圧指令値ｖ1d* を表す（８）式の末項ｖd に対応する信号を生成し、電圧指令値演算部１５に対して出力するようになっている。
【００１６】
速度推定値演算部１１は（１０）式に示すように、トルク分電流検出値ｉ1qを励磁分電流指令値ｉ1d* で除すと共にゲインｋωs を乗じることにより、すべり周波数推定値ωs'を得た後、後述する一次周波数演算部１４より与えられる一次周波数ω1 からこのすべり周波数推定値ωs'を減じることにより速度推定値ωr'を得る。そして、外部より与えられる速度指令値ωr*と速度推定値ωr'との差分つまり速度偏差は、速度制御器１２においてＰＩ制御及びリミッタ処理されトルク分電流指令値ｉ1q* となる。
【００１７】
このトルク分電流指令値ｉ1q* とトルク分電流検出値ｉ1qとの差分つまりトルク分電流偏差はトルク分電流制御器１３に入力される。このトルク分電流制御器１３は、トルク分電流偏差に対してＰＩ制御を行うもので、トルク分電圧指令値ｖ1q* を表す（９）式の末項ｖq に対応する信号を生成し、電圧指令値演算部１５に対して出力するようになっている。
【００１８】
また、上記トルク分電流制御器１３は、トルク分電流偏差を積分してＩ制御ゲインを乗じた積分結果ｅを一次周波数演算部１４に対して出力するようになっている。この一次周波数演算部１４は、積分結果ｅに定数を乗じて一次周波数ω1 を得ると、それを速度推定値演算部１１と電圧指令値演算部１５に対して出力する。さらに、一次周波数ω1 は時間積分されて回転磁束の位相角θが生成され、その位相角θは座標変換器６と座標変換器７に対して出力される。
【００１９】
電圧指令値演算部１５は、（８）式に示すように、励磁分電流制御器１０から与えられる信号ｖd に、励磁分電流検出値ｉ1dに一次抵抗値Ｒ1 を乗じたものを加えると共に、一次周波数ω1 に定数σＬ1 とトルク分電流検出値ｉ1qを乗じたものを減じて励磁分電圧指令値ｖ1d* を得ると、座標変換器７に対して出力するようになっている。
【００２０】
また、電圧指令値演算部１５は、（９）式に示すように、トルク分電流制御器１３から与えられる信号ｖq に、トルク分電流検出値ｉ1qに一次抵抗値Ｒ1 を乗じたものを加えると共に、一次周波数ω1 に定数σＬ1 と励磁分電流差分（ｉ1d−ｉ1d* ）を乗じたものを加えてトルク分電圧指令値ｖ1q* を得ると、座標変換器７に対して出力するようになっている。
【００２１】
一次抵抗同定部１６は、誘導機の駆動中において、励磁分電流の差分（ｉ1d* −ｉ1d）から（１５）式に従って一次抵抗Ｒ1 を同定するようになっている。ここで用いられる補正ゲインＫR は、前述したように過渡時に応答しない程度に小さく選ばれている。
【００２２】
【発明が解決しようとする課題】
このようなセンサレスベクトル制御においては、速度推定値演算部１１、一次周波数演算部１４、電圧指令値演算部１５等の演算に電動機定数が使用されている。これらの電動機定数は、駆動前に一次抵抗測定、無負荷試験、拘束試験等の特性試験により測定したり、インバータの有する機能により自動計測されたりする。しかしながら、電動機定数、中でも一次抵抗と二次抵抗は駆動に伴う誘導機の温度上昇により大きく変化し、その結果、実際の電動機定数と制御で用いられている電動機定数の間にずれが生じる。
【００２３】
特に、低速度領域においては周波数が低いため、インダクタンスに関する項が小さく抵抗に関する項が支配的になり、一次抵抗と二次抵抗のずれの影響が大きい。また、低速度領域では放熱効果が小さため誘導機内部の温度上昇が大きく、その分一次抵抗と二次抵抗のずれが増大する傾向がある。その結果、一次抵抗のずれは、一次電圧指令値に誤差電圧を重畳させ、特に低速度領域において一次周波数の推定誤差やトルクの低下を招く。また、二次抵抗のずれは、すべり周波数推定値の誤差をもたらし、結果として速度推定値に誤差が生じ速度精度の悪化を招く。この内、一次抵抗については、上述したように駆動中における同定方法が確立されており、制御で用いられる一次抵抗を補正することは可能であるが、二次抵抗に関しては駆動中の同定方法は未だ確立されておらず、その補正は不可能であった。
本発明は、上記の事情に鑑みてなされたもので、その目的は、誘導機の駆動中に一次抵抗及び二次抵抗を容易に同定することのできる誘導電動機制御装置を提供することにある。
【００２４】
【課題を解決するための手段】
上記目的を達成するため、本発明の誘導電動機制御装置は、出力電圧指令値に従って電圧を出力する電圧型インバータ主回路と、
誘導電動機の相電流検出値を、三相−二相変換後、一次周波数指令値で回転する回転座標系において二次磁束と同一方向（ｄ軸方向）成分である励磁分電流検出値と、二次磁束に対し直交方向（ｑ軸方向）成分であるトルク分電流検出値とに分離する座標変換手段と、
励磁分電流指令値と、速度指令値又はトルク分電流指令値と、励磁分電流検出値と、トルク分電流検出値と、電動機定数とから回転座標系でベクトル制御の演算を行い、一次周波数指令値と、ｄ軸方向成分である励磁分電圧指令値と、ｑ軸方向成分であるトルク分電圧指令値とを出力するベクトル制御演算手段と、
所定の一次周波数以下の領域において、励磁分電圧指令値とトルク分電圧指令値に、特定のパターンに従って変化し且つ一次周波数に比して高周波となる同定用励磁分電圧値と同定用トルク分電圧値を夫々短時間加算する同定用電圧加算手段と、
同定用励磁分電圧値と同定用トルク分電圧値が夫々加算された後の励磁分電圧指令値とトルク分電圧指令値を、回転座標系から静止座標系に変換後三相−二相変換して出力電圧指令値とする座標変換手段と、
同定用励磁分電圧値及び同定用トルク分電圧値と、それら同定用電圧が印加された時の励磁分電流検出値及びトルク分電流検出値の変化分とから一次抵抗と二次抵抗の直列合成値を演算する抵抗合成値演算手段とを備える（請求項１）。
【００２５】
このとき、同定用励磁分電圧値と同定用トルク分電圧値が夫々加算された励磁分電圧指令値及びトルク分電圧指令値と、それら同定用電圧が印加された時の励磁分電流検出値及びトルク分電流検出値とから一次抵抗と二次抵抗の直列合成値を演算することもできる（請求項４）。
斯様に構成すれば、誘導機の駆動中に一次抵抗と二次抵抗の直列合成値を求めることができる。
【００２６】
この場合、ｄ軸方向成分とｑ軸方向成分が夫々励磁分電圧指令値とトルク分電圧指令値である指令電圧ベクトルの方向に沿って、同定用励磁分電圧値と同定用トルク分電圧値を夫々励磁分電圧指令値とトルク分電圧指令値に加算すると良い（請求項５）。
斯様に構成すれば、指令電圧ベクトルの方向は変わらず大きさのみが変化するので同定用電圧を加算する際の演算が容易に行え、電圧変化誤差が小さくなり、精度の高い直列合成値を得ることができる。
【００２７】
また、ｄ軸方向成分とｑ軸方向成分が夫々励磁分電流検出値とトルク分電流検出値である検出電流ベクトルの方向に沿って、同定用励磁分電圧値と同定用トルク分電圧値を夫々励磁分電圧指令値とトルク分電圧指令値に加算すると良い（請求項６）。
斯様に構成すれば、同定用電圧を印加した前後において、検出電流ベクトルの方向は変わらず大きさのみ変化するので電流変化誤差が小さく、また、指令電圧ベクトル及び指令電圧ベクトルの変化分（同定用電圧ベクトル）は指令値として既知であるので、より精度の高い直列合成値を得ることができる。
【００２８】
座標変換手段において励磁分電圧指令値とトルク分電圧指令値とから出力電圧指令値を生成した後、同定用電圧加算手段により、所定の一次周波数以下の領域において、その出力電圧指令値に特定のパターンに従って変化し且つ一次周波数に比して高周波となる同定用電圧値を短時間加算し、抵抗合成値演算手段において同定用電圧値と、その同定用電圧が印加された時の相電流検出値の変化分とから一次抵抗と二次抵抗の直列合成値を演算することもできる（請求項２）。
このとき、抵抗合成値演算手段において、同定用電圧値が加算された出力電圧指令値と、その同定用電圧が印加された時の相電流検出値とから一次抵抗と二次抵抗の直列合成値を演算することもできる（請求項７）。
斯様に構成すれば、直列合成値の演算において、電圧指令値と電流検出値に座標変換による演算誤差が入り込まないので、より正確な直列合成値を得ることができる。
【００２９】
座標変換手段において励磁分電圧指令値とトルク分電圧指令値とから出力電圧指令値を生成した後、ＰＷＭ制御手段において出力電圧指令値から電圧型インバータ主回路の各ゲートに与えるＰＷＭ波形を形成し、同定用電圧加算手段により、所定の一次周波数以下の領域において、ＰＷＭ波形のパルス幅を特定のパターンに従って変化させることにより電圧型インバータ主回路の出力電圧に一次周波数に比して高周波となる同定用電圧を短時間加算し、抵抗合成値演算手段において同定用電圧値と、その同定用電圧が印加された時の相電流検出値の変化分とから一次抵抗と二次抵抗の直列合成値を演算することもできる（請求項３）。
このとき、抵抗合成値演算手段において、同定用電圧値が加算された出力電圧指令値と、その同定用電圧が印加された時の相電流検出値とから一次抵抗と二次抵抗の直列合成値を演算することもできる（請求項８）。
斯様に構成すれば、ＰＷＭ波形を直接制御できるので同定用電圧の誘導機への印加が高速に行われ、且つ直列合成値の演算に座標変換による演算誤差が入り込まないので、より正確な直列合成値を得ることができる。
【００３０】
さらに、上記した抵抗合成値演算手段により演算される一次抵抗と二次抵抗の直列合成値から、別の手段によって同定された一次抵抗値を減じることにより二次抵抗値を算出する二次抵抗同定手段を備え（請求項９）、一次抵抗と二次抵抗の直列合成値、又は一次抵抗値と二次抵抗値に基づいてベクトル制御演算手段で用いられる電動機定数を補正する定数補正手段を備え（請求項１０）、一次抵抗と二次抵抗の直列合成値、又は一次抵抗値と二次抵抗値を記憶手段に記憶し、次の運転開始時にこの記憶値を読み出してベクトル制御演算手段で用いられる電動機定数を補正する学習手段を備える（請求項１１）ことができる。
【００３１】
斯様に構成すれば、誘導機の駆動中に二次抵抗値を同定でき（請求項９）、制御で用いられる一次抵抗値及び二次抵抗値と誘導機の実際の抵抗値（真値）とのずれを減少させることができる（請求項１０）ので、誘導機の温度変化に関わらず速度及びトルクについて高精度な制御が可能となる。また、学習機能を備えることにより、運転開始時の一次抵抗値及び二次抵抗値のずれを小さくでき、より安定且つ高精度な制御が可能となる（請求項１１）。
【００３２】
【発明の実施の形態】
以下、本発明の第１実施例について、図１乃至図７を参照して説明する。図１は、本実施例の制御系のブロック図を示す図である。図２０と同一部分には同一符号を付して説明を省略し、以下異なる部分についてのみ説明する。
【００３３】
同定用電圧演算部１８は、一次周波数ω1 が十分に小さい領域で定常運転状態にある時に、一次抵抗と二次抵抗の直列合成値を同定するためのパルス状の同定用電圧を発生するものである。その同定用励磁分電圧Δｖd と同定用トルク分電圧Δｖq は、同定用電圧加算手段１７の加算器により、夫々電圧指令値演算部１５から出力された励磁分電圧指令値ｖ1d* とトルク分電圧指令値ｖ1q* に加算され、さらに抵抗合成値演算部１９に対しても出力される。
【００３４】
抵抗合成値演算部１９は、上記同定用励磁分電圧Δｖd 及び同定用トルク分電圧Δｖq と、これら同定用電圧が誘導機に印加された時の一次電流の励磁分電流検出値ｉ1d及びトルク分電流検出値ｉ1qの変化分とから、後述する演算により一次抵抗と二次抵抗の直列合成値を演算するようになっている。
なお、図１に示した制御系、座標変換器６、７、及びＰＷＭ制御部８等は、全て制御手段たるマイクロコンピュータ及びその周辺入出力回路によって構成されている。
【００３５】
次に、抵抗値の同定原理、及び本実施例の作用について図２乃至図７をも参照しながら詳述する。定常状態における誘導機の等価回路を示す図２において、 （Ｌ1 −Ｍ）は一次側漏れインダクタンス、（Ｌ2 −Ｍ）は二次側漏れインダクタンスを表す。また、相互インダクタンスＭに流れる電流ｉm は励磁電流に相当するものである。そして、二次抵抗Ｒ2 をすべりｓで除した（Ｒ2 ／ｓ）の項に消費される電力は同期ワットと呼ばれるものであり、これは更に二次巻線の銅損と機械出力とに分離して表すことができる。
【００３６】
ここで、誘導機が低速で定常運転されているときには、上記等価回路の中で一次側漏れインダクタンス（Ｌ1 −Ｍ）の項は微小となり無視することができる。また、（Ｒ2 ／ｓ）の項を二次巻線の銅損に関与する項である二次抵抗Ｒ2 と、機械出力に関与する項である（１−ｓ）Ｒ2 ／ｓとに分離し、（１−ｓ）Ｒ2 ／ｓの項と二次側漏れインダクタンス（Ｌ2 −Ｍ）の項とに誘起する電圧のベクトル和を誘起電圧ｅbkと定義すると、図２に示す等価回路は図３に示す等価回路へと変換される。図４はこのときのベクトル図を示し、一次電圧ベクトルｖ1 は、誘起電圧ｅbk、二次抵抗による電圧降下Ｒ2 ｉ2 、及び一次抵抗による電圧降下Ｒ1 ｉ1 のベクトル和に等しくなる。
【００３７】
さて、本発明は一次電圧に時間幅の狭いパルス状の同定用電圧を印加し、その印加時の一次電圧と一次電流、又はそれらの変化分から抵抗値を同定するものである。この場合、同定用電圧は高周波信号と見なすことができるので、図３に示す等価回路を更に高周波回路として表した等価回路へと変換する。高周波回路においては、相互インダクタンスＭに流れる励磁電流ｉm はほとんど変化しないので、この電流を定電流源ｉm に置き換え、更にこの定電流源を等価的な定電圧源を用いた構成に変更すると、図５に示す高周波等価回路を得る。ここで、新たに現れる定電圧源ｅim（＝Ｒ2 ｉm ：但しｉm ＝ｉ2 −ｉ1 ）は、図３に示す等価回路から励磁電流項を消去するために付加したもので誘起電圧に対応する。この高周波等価回路は、低速運転時における高周波入力電圧に対してのみ適用できるもので、誘起電圧ｅbk、ｅimに対し、一次抵抗Ｒ1 と二次抵抗Ｒ2 とが直列に接続されている回路構成に特徴を有する。
【００３８】
図６はこの高周波等価回路を表すベクトル図で、一次電圧ベクトルｖ1 は誘起電圧ｅbk、ｅim、及び一次抵抗と二次抵抗の直列合成値による電圧降下（Ｒ1 ＋Ｒ2 ）ｉ1 とのベクトル和に等しくなる。従って、誘導機のインピーダンスは、一次抵抗と二次抵抗の直列合成値（Ｒ1 ＋Ｒ2 ）だけとなり、次式のベクトル演算から一次抵抗と二次抵抗の直列合成値（Ｒ1 ＋Ｒ2 ）が得られる。
Ｒ1 ＋Ｒ2 ＝Δｖ1 ／Δｉ1 …（１６）
ただし、Δｖ1 ：一次電圧ベクトルの変化分（同定用電圧ベクトル）
Δｉ1 ：一次電流ベクトルの変化分
【００３９】
以上の同定原理を本実施例に適用すると、誘導機の漏れインダクタンスが無視できる程度に十分に低い一次周波数領域において定常運転しているときに、同定用電圧加算手段１７により電圧指令値ｖ1*（＝Δｖ1d* ＋ｊΔｖ1q* ）にパルス状の同定用電圧値Δｖ1 （＝Δｖd ＋ｊΔｖq ）を加算すればよい。このとき、抵抗合成値演算部１９において、同定用電圧値Δｖ1 とその印加前後における一次電流の変化分Δｉ1 とを用いて（１６）式のベクトル演算を実行すれば一次抵抗と二次抵抗の直列合成値を得ることができる。
【００４０】
図７は同定用電圧印加時におけるベクトル図を示す。同定用電圧加算後の一次電圧ベクトルｖ1'は、加算前の定常状態における一次電圧ベクトルｖ1 に、ｄ軸成分がΔｖd 、ｑ軸成分がΔｖq である同定用電圧ベクトルΔｖ1 を加算したもので、印加前の定常状態における一次電流ベクトルｉ1 が印加後ｉ1'へと変化することを表している。
【００４１】
なお、抵抗合成値演算部１９における演算では、同定用電圧を印加した後、漏れインダクタンスに起因する一次電流の立上がりの遅れ、及び二次抵抗に関する表皮効果の影響を考慮して、印加後一定時間が経過した後の一次電流検出値を用いて一次電流の変化分を計算する。また、同定用電圧の印加、及び一次電流の検出は、励磁電流や誘起電圧ｅbk、ｅimが変化しない程度の短時間に終える必要がある。
【００４２】
以上のように本実施例によれば、誘導機が低速度で定常運転されているときに、高周波と見なせる程度の短時間のパルス状の同定用電圧を誘導機に印加する。この場合、誘導機の等価回路は誘起電圧と一次抵抗と二次抵抗の直列接続となり、しかも短時間の一次電圧変化に対しては誘起電圧は変化しないので、同定用電圧とその同定用電圧印加前後の一次電流変化分とから一次抵抗と二次抵抗の直列合成値を演算することができる。
【００４３】
次に、本発明の第２実施例について、電気的構成を示す図８を参照して説明する。図１９と同一部分には同一符号を付して説明を省略し、異なる部分についてのみ説明する。
同定用電圧演算部２１は、一次周波数ω1 が十分に小さい領域で且つ定常運転状態にある時に、一次抵抗と二次抵抗の直列合成値を同定するためのパルス状の同定用電圧を発生するものである。その同定用Ｕ相電圧Δｖu 、同定用Ｖ相電圧Δｖv 、及び同定用Ｗ相電圧Δｖw は、同定用電圧加算手段２０の加算器により、夫々座標変換器７から出力されたＵ相出力電圧指令値ｖu*、Ｖ相出力電圧指令値ｖv*、及びＷ相出力電圧指令値ｖw*に加算され、さらに抵抗合成値演算部２２に対しても出力される。
【００４４】
抵抗合成値演算部２２は、上記同定用電圧Δｖu 、Δｖv 、Δｖw と、これら同定用電圧が誘導機に印加された時の一次電流のＶ相電流検出値ｉv 、Ｗ相電流検出値ｉw 、及び−（ｉv ＋ｉw ）として演算されるＵ相電流検出値ｉu の各変化分とから、一次抵抗と二次抵抗の直列合成値を演算するようになっている。
【００４５】
以上のように構成された第２実施例によれば、同定用電圧値Δｖu 、Δｖv 、Δｖw からなる同定用電圧ベクトルΔｖ1 と、相電流検出値ｉu 、ｉv 、ｉw からなる一次電流ベクトルの変化分Δｉ1 とを用いて、（１６）式のベクトル演算に従って一次抵抗と二次抵抗の直列合成値を得ることができる。この場合、第１実施例と異なり、演算に用いる一次電流ベクトルの変化分Δｉ1 には座標変換器６による座標変換が施されていないので、座標変換器６における演算誤差が無くなる。また、同定用電圧ベクトルΔｖ1 も、座標変換器７からＰＷＭ制御部８に対して出力される出力電圧指令値に直接加算されるので、座標変換器７における演算誤差が無くなり、同定用電圧が正確に誘導機に印加される。従って、より正確な抵抗の同定が可能となる。
【００４６】
次に、本発明の第３実施例について、電気的構成を示す図９を参照して説明する。図１９と同一部分には同一符号を付して説明を省略し、異なる部分についてのみ説明する。
同定用電圧演算部２４は、一次周波数ω1 が十分に小さい領域で定常運転状態にある時に、ＰＷＭ制御部２５に対し、一次抵抗と二次抵抗の直列合成値を同定するための同定用電圧の発生を指示する指示信号ａ1 を出力する。この指示信号ａ1 は同時に抵抗合成値演算部２６にも与えられる。ＰＷＭ制御部２５では、この指示信号ａ1 が入力されると、図１０に示すようにその入力期間だけＰＷＭ波形のパルス幅を変化させるようになっている。つまり、定常運転状態においてＰＷＭ制御部２５から出力されるＰＷＭ波形（実線）は、周期Ｔc （＝１／ｆc ：ｆc はキャリア周波数）、パルス幅Ｐw1を有している。このとき、同定用電圧の発生を指示する指示信号ａ１がＰＷＭ制御部２５に入力されると、キャリア毎に図中破線で示すようにその同定用電圧に応じてパルス幅をＰw2に変化させる。その結果、インバータ主回路４の出力電圧が変化するので誘導機に同定用電圧を印加することが可能となる。
【００４７】
抵抗合成値演算部２６は、同定用電圧演算部２４からの指示信号ａ1 を得て誘導機に印加される同定用電圧Δｖu 、Δｖv 、Δｖw を生成し、これら同定用電圧と、これら同定用電圧が誘導機に印加された時の一次電流のＶ相電流検出値 ｉv 、Ｗ相電流検出値ｉw 、及び−（ｉv ＋ｉw ）として演算されるＵ相電流検出値ｉu の各変化分とから、一次抵抗と二次抵抗の直列合成値を演算するようになっている。
【００４８】
以上の構成からなる本実施例によれば、指示信号ａ１にて指示される同定用電圧値Δｖu 、Δｖv 、Δｖw からなる同定用電圧ベクトルΔｖ1 と、相電流検出値ｉu 、ｉv 、ｉw からなる一次電流ベクトルの変化分Δｉ1 とを用いて、（１６）式のベクトル演算に従って一次抵抗と二次抵抗の直列合成値が得ることができる。この場合、演算に用いる一次電流ベクトル変化分Δｉ1 には座標変換器６による座標変換が施されていないので、座標変換器６における演算誤差が無くなる。また、同定用電圧ベクトルΔｖ1 は、ＰＷＭ制御部２５にてＰＷＭ波形を直接変化させて生成するので、座標変換器７における演算誤差が無くなると共に、同定用電圧が高速且つ正確に誘導機に印加される。従って、さらに正確に抵抗を同定することが可能となる。
【００４９】
次に、本発明の第４実施例について、制御部のブロック図を示す図１１を参照して説明する。図１及び図２０と同一の部分には同一符号を付して説明を省略する。
抵抗合成値演算部２７は、同定用電圧演算部１７において励磁分電圧指令値 ｖ1d* とトルク分電圧指令値ｖ1q* に夫々同定用励磁分電圧Δｖd と同定用トルク分電圧Δｖq が加算された後の励磁分電圧指令値ｖd*とトルク分電圧指令値 ｖq*、及びこれら同定用電圧が誘導機に印加された時の一次電流の励磁分電流検出値ｉ1d及びトルク分電流検出値ｉ1qとから、一次抵抗と二次抵抗の直列合成値を演算するようになっている。
【００５０】
本実施例では、同定用電圧が加算された一次電圧と検出された一次電流夫々の変化分ではなく、一次電圧値と一次電流検出値そのものを使用して同定演算をする点に特徴を有する。一次抵抗と二次抵抗の直列合成値の同定原理については図２から図７に基づいて前述した通りであり、同定用電圧が加算された一次電圧ベクトルをｖ1'（＝ｖ1 ＋Δｖ1 ）、同定用電圧が印加された後に検出された一次電流ベクトルをｉ1'とすると、一次抵抗と二次抵抗の直列合成値（Ｒ1 ＋Ｒ2 ）は次式により演算することができる。
Ｒ1 ＋Ｒ2 ＝ｖ1'／ｉ1' …（１７）
【００５１】
なお、この場合においても、抵抗合成値演算部２７における演算では、同定用電圧を印加した後、一定時間が経過した後の一次電流検出値を用いて計算する必要がある。また、同定用電圧の印加、及び一次電流の検出は、励磁電流や誘起電圧ｅbk、ｅimの値が変化しない程度の短時間に終える必要がある。
【００５２】
以上のように構成された第４実施例によれば、誘導機が低速度で定常運転されているときに、高周波電圧と見なせる程度の短時間のパルス状の同定用電圧を一次電圧指令値に印加する。この場合、誘導機の等価回路は誘起電圧と一次抵抗と二次抵抗の直列接続となり、しかも短時間の一次電圧変化に対しては誘起電圧は変化しないので、同定用電圧とその同定電圧用印加後の一次電流とから一次抵抗と二次抵抗の直列合成値を演算することができる。
【００５３】
次に、本発明の第５実施例について、電気的構成を示す図１２を参照して説明する。図８及び図１９と同一部分には同一符号を付して説明を省略する。
抵抗合成値演算部２８は、同定用電圧加算手段２０において座標変換器７から出力されたＵ相出力電圧指令値ｖu*、Ｖ相出力電圧指令値ｖv*、及びＷ相出力電圧指令値ｖw*と同定用電圧Δｖu 、Δｖv 、Δｖw が夫々加算された後の各相出力電圧指令値ｖu** 、ｖv** 、ｖw** と、これらの同定用電圧が誘導機に印加された時の一次電流のＶ相電流検出値ｉv 、Ｗ相電流検出値ｉw 、及び−（ｉv ＋ｉw ）として演算されるＵ相電流検出値ｉu とから、一次抵抗と二次抵抗の直列合成値を演算するようになっている。
【００５４】
以上のように構成された第５実施例によれば、同定用電圧値加算後の各相出力電圧指令値ｖu** 、ｖv** 、ｖw** からなる一次電圧ベクトルと、相電流検出値ｉu 、ｉv 、ｉw からなる一次電流ベクトルｉ1 とを用いて、（１７）式のベクトル演算に従って一次抵抗と二次抵抗の直列合成値が得ることができる。この場合、第２実施例と同様に、演算に用いる一次電流ベクトルｉ1 には座標変換器６による座標変換が施されていないので、座標変換器６における演算誤差が無くなる。また、同定用電圧ベクトルΔｖ1 も、座標変換器７からＰＷＭ制御部８に対し出力される出力電圧指令値に直接加算されるので、座標変換器７における演算誤差が無くなり、同定用電圧が正確に誘導機に印加される。従って、より正確な抵抗の同定が可能となる。
【００５５】
次に、本発明の第６実施例について、電気的構成を示す図１３を参照して説明する。図９、図１９と同一部分には同一符号を付して説明を省略する。
同定用電圧演算部２４は、一次周波数ω1 が十分に小さい領域で定常運転状態にある時に、ＰＷＭ制御部２９に対し同定用電圧の発生指示信号ａ1 を出力する。ＰＷＭ制御部２９では、この指示信号ａ1 が入力されると、同定用電圧を誘導機に印加させるためにキャリア毎にＰＷＭ波形のパルス幅を変化させ、同時にその変化したパルス幅に関する信号を一次電圧信号ａ2 として抵抗合成値演算部３０に出力するようになっている。
【００５６】
抵抗合成値演算部３０は、ＰＷＭ制御部２９からの一次電圧信号ａ2 を用いて同定用電圧加算後の誘導機一次電圧ｖu 、ｖv 、ｖw を生成し、これら一次電圧と、同定用電圧が誘導機に印加された時の一次電流のＶ相電流検出値ｉv 、Ｗ相電流検出値ｉw 、及び−（ｉv ＋ｉw ）として演算されるＵ相電流検出値ｉu とから、一次抵抗と二次抵抗の直列合成値を演算するようになっている。
【００５７】
以上のように構成された本実施例によれば、同定用電圧値加算後の一次電圧ベクトルｖ1 と一次電流ベクトルｉ1 とを用いて、（１７）式のベクトル演算に従って一次抵抗と二次抵抗の直列合成値を得ることができる。この場合、第３実施例と同様に、演算に用いる一次電流ベクトルｉ1 には座標変換器６による座標変換が施されていないので、座標変換器６における演算誤差が無くなる。また、同定用電圧ベクトルΔｖ1 は、ＰＷＭ制御部２９にてＰＷＭ波形を直接変化させて生成するので、座標変換器７における演算誤差が無くなると共に、同定用電圧が高速且つ正確に誘導機に印加される。従って、さらに正確に抵抗を同定することが可能となる。
【００５８】
次に、本発明の第７実施例について、図１４に示すベクトル図を参照して説明する。本実施例では、同定用電圧を励磁分電圧指令値ｖ1d* とトルク分電圧指令値ｖ1q* とに加算する構成をとる図１及び図１１において、同定用電圧演算部１８で生成される同定用励磁分電圧Δｖd と同定用トルク分電圧Δｖq からなる同定用電圧ベクトルΔｖ1 の方向を、電圧指令値演算部１５から出力される励磁分電圧指令値ｖ1d* とトルク分電圧指令値ｖ1q* からなる指令電圧ベクトルｖ1*の方向と同一方向にとる。
【００５９】
このような同定用電圧を用いると、加算前後の指令電圧ベクトルの方向は変わらず大きさのみ変化するので、同定用電圧を加算する際のベクトル演算が容易に行え電圧変化誤差が小さくなる。従って、（１６）式又は（１７）式を用いてより精度の高い直列合成値を得ることができる。
【００６０】
次に、本発明の第８実施例について、図１５に示すベクトル図を参照して説明する。本実施例では、同定用電圧を励磁分電圧指令値ｖ1d* とトルク分電圧指令値ｖ1q* とに加算する構成をとる図１及び図１１において、同定用電圧演算部１８で生成される同定用励磁分電圧Δｖd と同定用トルク分電圧Δｖq からなる同定用電圧ベクトルΔｖ1 の方向を、励磁分電流検出値ｉ1dとトルク分電流検出値ｉ1qからなる検出電流ベクトルｉ1 の方向と同一方向にとる。
【００６１】
このような同定用電圧を用いると、検出電流ベクトルの方向は変わらず大きさのみ変化するので電流変化誤差が小さく、また、指令電圧ベクトル又は指令電圧ベクトルの変化分（同定用電圧ベクトル）は指令値として制御装置内で既知であるので、（１６）式又は（１７）式を用いてより精度の高い直列合成値を得ることができる。
【００６２】
次に、本発明の第９実施例について、二次抵抗同定部のブロック図を示す図１６を参照して説明する。
この二次抵抗同定部では、抵抗合成値演算部２７にて前記（１７）式によって同定された一次抵抗と二次抵抗の直列合成値（Ｒ1 ＋Ｒ2 ）から、一次抵抗同定部１６にて前記（１５）式によって同定された一次抵抗値を減じることにより二次抵抗値Ｒ2 を算出するようになっている。そして、図示しない定数補正手段は、これら同定された一次抵抗値と二次抵抗値に基づいて、ベクトル制御演算に用いられる一次抵抗値と二次抵抗値を真値へと補正するようになっている。
【００６３】
本実施例によれば、誘導機の駆動中において、既に確立された同定法により得られる一次抵抗値と、本発明により得ることができる一次抵抗と二次抵抗の直列合成値とを用いて、未だ同定法が確立していない二次抵抗値を容易に得ることができる。そして、得られた抵抗値に基づいてベクトル制御演算に用いられる抵抗値を補正するので、誘導機の駆動に伴う巻線の温度変化があっても、高い速度精度とトルクの線形性を維持することができる。
【００６４】
さらに、本発明の第１０実施例について、学習手段を備えた抵抗同定部のブロック図を示す図１７を参照して説明する。
本実施例は、誘導機の駆動中において、抵抗合成値演算部２７にて演算された一次抵抗と二次抵抗の直列合成値（Ｒ1 ＋Ｒ2 ）、一次抵抗同定部１６にて同定された一次抵抗値、及びこれらから算出される二次抵抗値を、記憶手段たるメモリ３１、特には不揮発性メモリ又は電池によりバックアップされた揮発性メモリに格納する。そして、この格納値は次の運転開始時に読み出され、ベクトル制御演算に使用されるようになっている。このような学習機能を付加した本実施例によれば、運転開始時の抵抗値のずれを小さく抑えることができ、安定した始動と、始動直後からの高精度かつ安定した制御が可能となる。
【００６５】
本発明は上記し且つ図面に記載した実施例にのみ限定されるものではなく、次のような変形または拡張が可能である。
誘導機の一次電圧に印加するパルス状の同定用電圧は、図１８に示すようなフレンチハット形状の波形としても良い。この波形は、０電圧レベルを中心として負側、正側、負側と交互にステップ変化を繰り返すもので、負側の電圧値と正側の電圧値の絶対値が等しく、且つ負側の電圧を有している時間（▲１▼部と▲３▼部の和：Ｔ＋Ｔ＝２Ｔ）と正側の電圧を有している時間（▲２▼部：２Ｔ）とが等しくなっている。
【００６６】
また、図示しないが、０電圧レベルを中心として負側、正側、負側と交互にステップ変化を繰り返すもので、正側の電圧値が負側の電圧値の絶対値の２倍に等しく、且つ負側のパルスの電圧幅（▲１▼部と▲３▼部）と正側のパルスの電圧幅（▲２▼部）とが全て等しくなる波形であっても良い。
【００６７】
これら同定電圧波形は、その平均電圧が０、つまり直流成分を含まないものであり、同定用電圧の印加に伴う励磁電流や誘起電圧の変化を十分に小さくすることができる。また、波形がステップ変化する毎に抵抗値の同定が可能なので、１度の同定用電圧の印加で複数の演算結果を得ることができ、平均処理等を併用すれば、より精度の高い抵抗値の同定が可能となる。なお、この場合、パルス幅Ｔは誘起電圧が変化する時間よりも短いことが望ましいが、負荷のイナーシャが大きいような場合、及び誘起電圧が正確に分かるような場合にはパルス幅Ｔを広くとることができる。
【００６８】
また、同定用電圧印加後の一次電流の検出は、前述のように漏れインダクタンスや二次抵抗に関する表皮効果の影響を考慮して、印加後一定時間が経過した後に行われるが、印加直後に例えば指数関数などを用いて一次電流の最終値を予測し、その予測値を用いて抵抗値の同定演算を行っても良い。この方法によれば、さらに短時間で抵抗値の同定が可能となる。
【００６９】
第９実施例において、一次抵抗と二次抵抗の直列合成値（Ｒ1 ＋Ｒ2 ）から一次抵抗値と二次抵抗値の各値を確定する別の方法として、予め測定された一次抵抗値Ｒ1 と二次抵抗値Ｒ2 の比率を基に、一次抵抗と二次抵抗の直列合成値 （Ｒ1 ＋Ｒ2 ）を各抵抗値に配分してもよい。この場合、速度指令値や負荷に応じて比率を変えたり、経験上の関数を用いても良い。その結果、一次抵抗同定部１６が不要となる。
【００７０】
さらに、予め使用者が電動機定数の同定及び補正を許可する領域（リフレッシュイネーブル領域）を設定できるようにし、誘導機がこの領域内で運転されており、同定可能な回転速度と定常状態であることの判定をした後、同定可能な場合には自動的に同定用電圧の印加、一次電流の検出、抵抗値同定演算、及び定数補正からなる処理を開始するような構成としても良い。
【００７１】
同定した一次抵抗と二次抵抗の直列合成値（Ｒ1 ＋Ｒ2 ）、又は一次抵抗値及び二次抵抗値と、予め測定されている一定温度下におけるこれら抵抗値と、一次／二次巻線の抵抗温度係数とから、巻線の温度上昇、つまり誘導機の温度上昇を算出し、温度センサの代替えとして使用する構成としても良い。
【００７２】
【発明の効果】
本発明は以上説明した通りであるので、以下の効果を奏する。
請求項１または４記載の誘導電動機制御装置によれば、誘導機が低速度で定常運転されている場合において、高周波電圧印加時の等価回路が誘起電圧と一次抵抗と二次抵抗の直列接続として表されることに着目し、制御装置内の同定用電圧加算手段により、所定の一次周波数以下の領域において、ベクトル制御演算手段から出力される励磁分電圧指令値とトルク分電圧指令値に、特定のパターンに従って変化し且つ一次周波数に比して高周波となる同定用励磁分電圧値と同定用トルク分電圧値を夫々短時間加算し、抵抗合成値演算手段において、その同定用電圧ベクトルを同定用電圧印加時の励磁分電流検出値及びトルク分電流検出値からなる一次電流ベクトルの変化分で除すことにより一次抵抗と二次抵抗の直列合成値を演算するようにした（請求項１）。また、抵抗合成値演算手段において、同定用電圧加算後の一次電圧ベクトルを同定用電圧印加時の一次電流ベクトルで除すことにより直列合成値を演算するようにした（請求項４）。これらにより、誘導機の駆動中においても一次抵抗と二次抵抗の直列合成値を得ることが可能となる。
【００７３】
請求項２または７記載の誘導電動機制御装置によれば、座標変換手段において励磁分電圧指令値とトルク分電圧指令値とから各相の出力電圧指令値を生成した後、同定用電圧加算手段により、所定の一次周波数以下の領域において、その出力電圧指令値に特定のパターンに従って変化し且つ一次周波数に比して高周波となる同定用電圧値を短時間加算し、抵抗合成値演算手段において同定用電圧ベクトルをその同定用電圧が印加された時の相電流からなる検出電流ベクトルの変化分で除すことにより一次抵抗と二次抵抗の直列合成値を演算するようにした（請求項２）。また、抵抗合成値演算手段において、同定用電圧加算後の一次電圧ベクトルを同定用電圧印加時の一次電流ベクトルで除すことにより直列合成値を演算するようにした（請求項７）。これらにより、一次電流ベクトルから座標変換による演算誤差が除かれ、同定用電圧ベクトルも座標変換後の出力電圧指令値に直接加算されるので、より正確な抵抗の同定が可能となる。
【００７４】
請求項３または８記載の誘導電動機制御装置によれば、同定用電圧加算手段により、所定の一次周波数以下の領域において、ＰＷＭ波形のパルス幅を特定のパターンに従って変化させることにより電圧型インバータ主回路の出力電圧に一次周波数に比して高周波となる同定用電圧を短時間加算し、抵抗合成値演算手段において同定用電圧ベクトルを同定用電圧が印加された時の検出電流ベクトルの変化分で除すことにより一次抵抗と二次抵抗の直列合成値を演算するようにした（請求項３）。また、抵抗合成値演算手段において、同定用電圧加算後の一次電圧ベクトルを同定用電圧印加時の一次電流ベクトルで除すことにより直列合成値を演算するようにした（請求項８）。従って、一次電流ベクトルから座標変換による演算誤差が除かれ、同定用電圧の加算はＰＷＭ波形のパルス幅を直接変化させることにより高速に行われるので、より正確な抵抗の同定が可能となる。
【００７５】
請求項５記載の誘導電動機制御装置によれば、励磁分電圧指令値とトルク分電圧指令値からなる指令電圧ベクトルの方向に沿って同定用電圧ベクトルを加算するので、指令電圧ベクトルの方向は変わらず大きさのみが変化する。従って、同定用電圧を加算する際の演算が容易に行え、精度の高い直列合成値を得ることができる。
【００７６】
請求項６記載の誘導電動機制御装置によれば、励磁分電流検出値とトルク分電流検出値からなる検出電流ベクトルの方向に沿って同定用電圧ベクトルを加算するので、同定用電圧を印加した前後において、検出電流ベクトルの方向は変わらず大きさのみ変化する。従って、電流変化誤差が小さくなり、また、指令電圧ベクトル及び同定用電圧ベクトルは指令値として既知であるため、より精度の高い直列合成値を得ることができる。
【００７７】
請求項９記載の誘導電動機制御装置によれば、抵抗合成値演算手段により演算される一次抵抗と二次抵抗の直列合成値から、別の手段によって同定された一次抵抗値を減じることにより二次抵抗値を同定することができる。
【００７８】
請求項１０記載の誘導電動機制御装置によれば、一次抵抗と二次抵抗の直列合成値、又は一次抵抗値と二次抵抗値に基づいてベクトル制御演算手段で用いられる電動機定数を補正するので、誘導機の温度変化に関わらず速度及びトルクについて高精度で安定した制御が可能となる。
【００７９】
請求項１１記載の誘導電動機制御装置によれば、同定した一次抵抗と二次抵抗の直列合成値、又は一次抵抗値と二次抵抗値を記憶手段に記憶し、次の運転開始時において、その抵抗値を基にベクトル制御演算手段で用いられる電動機定数を補正することができるので、安定した始動と、始動直後からの高精度かつ安定した制御が可能となる。
【図面の簡単な説明】
【図１】本発明の第１実施例を示す制御系のブロック図
【図２】定常状態における誘導電動機の等価回路
【図３】誘起電圧を用いた誘導電動機の等価回路
【図４】誘起電圧を用いた誘導電動機の等価回路を示すベクトル図
【図５】誘導電動機の高周波等価回路
【図６】誘導電動機の高周波等価回路を示すベクトル図
【図７】同定用電圧印加時のベクトル図
【図８】本発明の第２実施例を示す電気的構成図
【図９】本発明の第３実施例を示す図８相当図
【図１０】本発明の第３実施例におけるＰＷＭ波形を示す図
【図１１】本発明の第４実施例を示す図８相当図
【図１２】本発明の第５実施例を示す図８相当図
【図１３】本発明の第６実施例を示す図８相当図
【図１４】本発明の第７実施例を示す図７相当図
【図１５】本発明の第８実施例を示す図７相当図
【図１６】本発明の第９実施例における二次抵抗同定部のブロック図
【図１７】本発明の第１０実施例における抵抗同定部のブロック図
【図１８】同定用電圧波形の１例を示す図
【図１９】従来技術を示す図８相当図
【図２０】従来技術を示す図１相当図
【符号の説明】
４はインバータ主回路、５は誘導電動機、６、７は座標変換器、８、２５、２９はＰＷＭ制御部、９はセンサレスベクトル制御部、１５は電圧指令値演算部、１６は一次抵抗同定部、１７、２０、２３は同定用電圧加算手段、１８、２１、２４は同定用電圧演算部、１９、２２、２６〜２８、３０は抵抗合成値演算部である。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vector control apparatus for an induction motor, and more particularly to an induction motor control apparatus having a function of identifying a primary resistance and a secondary resistance during driving of the induction motor.
[0002]
[Prior art]
As is well known, vector control of an induction motor (hereinafter simply referred to as an induction machine) has characteristics that surpass that of a DC motor in its control performance, and is frequently used in various fields in combination with ease of maintenance of induction machines. . More recently, for example, speed sensorless vector control as shown in FIG. 19 has been used as a control method that can improve low-speed torque characteristics as compared with V / f control without a speed detector. However, the sensor-equipped or sensorless vector control linearizes the output torque and enables high-speed and high-precision control. On the other hand, since the motor constants are used in the vector calculation in the control device, there is a deviation in the motor constants. As a result, control performance deteriorates and unstable phenomena occur. Therefore, as an example, the control principle and the method of identifying the motor constant will be described below for the speed sensorless vector control shown in Electrology D, Vol. 114, No. 2.
[0003]
When the voltage equation of the induction machine is expressed on rotating coordinates (dq coordinates) rotating at an angular velocity ω1, the equation (1) is obtained.
[0004]
[Formula 1]

[0005]
In the equation (1), λd ′ and λq ′ are obtained by dividing the d-axis component λd and the q-axis component λq of the secondary magnetic flux linkage number λ by the mutual inductance M, as shown in the following equation. It is the quantity which has.
λ ′ = λd ′ + jλq ′ (2)
λd '= λd / M (3)
λq ′ = λq / M (4)
The generated torque τ of the induction machine is given by the following equation, where n is the number of pole pairs.
.tau. = n (1-.sigma.) L1 (.lambda.d'i1q-.lambda.q'i1d) (5)
In the vector control, since the generated torque τ is linearized, it is necessary to control the excitation current i1d and the torque current i1q to be always orthogonal, and the orthogonalization condition is expressed by the following two equations.
λd ′ = constant value (6)
λq ′ = 0 (7)
[0006]
In the sensorless vector control, the primary voltage command values v1d * and v1q * applied to the induction machine are the excitation current command value i1d *, the speed command value ωr * input from the outside, and the primary current detection value i1d. , I1q and the like are calculated as follows.
v1d * = R1 i1d-σL1 ω1 i1q + vd (8)
v1q * = R1 i1q + σL1 ω1 (i1d−i1d *) + vq (9)
Here, the last term on the right side of equation (8) is for feeding back the deviation of the excitation current to v1d * through the P controller, and the last term on the right side of equation (9) is PI control of the deviation of the torque current. It is for returning to v1q * through the vessel. Then, after substituting v1q * represented by Equation (9) into v1q on the left side of the second row of Equation (1) and applying the relationship i1q = i1q *, which is established in the steady state, the primary frequency ω1 is It can be estimated using the voltage e which is an integral value of the deviation of the torque current.
[0007]
On the other hand, the slip frequency estimated value ωs ′ in the controller is obtained from the following equation using the slip frequency gain kωs.
ωs ′ = kωs i1q / i1d * (10)
kωs = R2 / L2 (11)
From this slip frequency estimated value ωs ′ and the primary frequency ω1, a speed estimated value ωr ′ is calculated as follows.
ωr ′ = ω1−ωs ′ (12)
By passing through the PI controller a speed deviation that is the difference between the speed estimated value ωr ′ thus obtained and the speed command value ωr * given from the outside, a torque component current command value i1q * is obtained.
[0008]
As can be seen from the above description of the control principle, the primary resistance R1, primary, secondary self-inductances L1, L2, and mutual inductance M are used for the calculation of the primary voltage command values v1d *, v1q *, and the estimated slip frequency. A secondary resistance R2 and a secondary self-inductance L2 are used for the calculation of ωs'. A method is conceivable in which the primary resistance R1 is electrically identified during driving of the induction machine and the result is reflected in the primary resistance R1 'used in the control. In the above paper, the deviation between the primary resistance R1 of the induction machine and the primary resistance R1 'used for control (hereinafter referred to as primary resistance setting error) is the excitation current command value i1d * and the excitation current detection value i1d. Focusing on the fact that it can be estimated based on the difference between the two, identification is performed as follows.
[0009]
A variable x1 ′ represented by the following equation is defined for the primary resistance R1 ′ used in the control.
x1 '= R1' / L1 (13)
When the primary resistance is deviated, the above x1 'is divided into a true value x1 and its minute change Δx1 as shown in the equation (14), and the minute change Δx1 is the difference between the excitation currents (i1d * −i1d). ) Can be converged to 0 by the correction calculation shown in the equation (15). In this case, since it is assumed that the primary self-inductance L1 does not change, it is considered that all the fluctuations of the variable x1 ′ are caused by the primary resistance R1 ′.
x1 '= x1 + .DELTA.x1 (14)
[0010]
[Formula 2]

[0011]
Since the purpose of equation (15) is to correct the change in resistance value due to temperature, even if the difference in excitation current (i1d * -i1d) changes during a transient, the correction gain KR is reduced so that it does not respond accordingly. It is necessary to select (or increase the period T).
In addition to the method described above, as an example in which the primary resistance setting error is estimated based on the fluctuation of the excitation current, Electronology D, Vol.
[0012]
Next, the configuration of the induction motor control device based on the above control principle and the primary resistance identification principle will be described with reference to FIGS. In FIG. 19 showing the electrical configuration, the buses of the U, V, and W phases of the three-phase AC power source 1 are connected to the respective phase input terminals of the rectifier circuit 2 constituted by a diode or the like connected in a three-phase bridge. The DC bus connected to the DC output terminal is connected to the smoothing capacitor 3 between the buses and to the input terminal of the voltage type inverter main circuit 4. This inverter main circuit 4 has six switching elements connected in a three-phase bridge, and its output terminal is connected to the input terminals of the U, V, and W phases of the induction machine 5.
[0013]
The coordinate converter 6 detects current of two phases, for example, V-phase and W-phase among the currents flowing through the windings of the U, V, and W phases of the induction machine 5 by current detection means such as CT, and the remaining 1 After calculating the phase (U-phase) current as -1 times the sum of the V-phase current and the W-phase current, three-phase to two-phase conversion is performed. Thereafter, rotational coordinate conversion (dq conversion) is executed based on the phase angle θ of the rotating magnetic flux output from the sensorless vector control unit 9 described later, and as a result, the excitation current detection value i1d and the torque current detection value of the primary current are obtained. i1q is obtained.
[0014]
The coordinate converter 7 converts the output voltage of each phase of the induction machines U, V, and W from the excitation voltage command value v1d * and the torque voltage command value v1q * by performing coordinate conversion opposite to that of the coordinate converter 6. When command values vu *, vv *, and vw * are obtained, they are output to the PWM control unit 8. Thus, the PWM control unit 8 generates a pulse signal subjected to pulse width modulation from the output voltage command values vu *, vv *, vw * and a carrier wave constituted by a triangular wave or the like, and passes through a drive circuit (not shown). The induction machine 5 is driven by giving a gate signal to each gate of the inverter main circuit 4.
[0015]
Next, the sensorless vector control unit 9 will be described with reference to the block diagram 20 showing the configuration of the control unit.
The excitation current command value i1d * given from the outside is given to the speed estimated value calculation unit 11 and the voltage command value calculation unit 15, and the difference between the excitation current detection value i1d, that is, the excitation current deviation is calculated. The deviation is input to the excitation current controller 10. This excitation current controller 10 performs P control on the excitation current deviation, generates a signal corresponding to the last term vd of the equation (8) representing the excitation voltage command value v1d *, and generates a voltage command. The data is output to the value calculation unit 15.
[0016]
As shown in the equation (10), the speed estimated value calculation unit 11 obtains the slip frequency estimated value ωs ′ by dividing the detected torque current value i1q by the excitation current command value i1d * and multiplying by the gain kωs. Thereafter, a speed estimated value ωr ′ is obtained by subtracting the slip frequency estimated value ωs ′ from a primary frequency ω1 given from a primary frequency calculating unit 14 described later. The difference between the speed command value ωr * and the estimated speed value ωr ′ given from the outside, that is, the speed deviation, is subjected to PI control and limiter processing in the speed controller 12 to become a torque current command value i1q *.
[0017]
The difference between the torque component current command value i1q * and the torque component current detection value i1q, that is, the torque component current deviation is input to the torque component current controller 13. The torque component current controller 13 performs PI control on the torque component current deviation, generates a signal corresponding to the last term vq of the equation (9) representing the torque component voltage command value v1q *, and generates a voltage command. The data is output to the value calculation unit 15.
[0018]
Further, the torque component current controller 13 outputs an integration result e obtained by integrating the torque component current deviation and multiplying by the I control gain to the primary frequency calculation unit 14. When the primary frequency calculating unit 14 multiplies the integration result e by a constant to obtain the primary frequency ω1, it outputs it to the speed estimated value calculating unit 11 and the voltage command value calculating unit 15. Further, the primary frequency ω 1 is integrated over time to generate a phase angle θ of the rotating magnetic flux, and the phase angle θ is output to the coordinate converter 6 and the coordinate converter 7.
[0019]
The voltage command value calculation unit 15 adds a signal vd given from the excitation current controller 10 by multiplying the excitation current detection value i1d by the primary resistance value R1 as shown in the equation (8). When the excitation voltage command value v1d * is obtained by subtracting the frequency ω1 multiplied by the constant σL1 and the torque component current detection value i1q, it is output to the coordinate converter 7.
[0020]
The voltage command value calculator 15 adds a signal vq given from the torque component current controller 13 to the torque component current detection value i1q multiplied by the primary resistance value R1 as shown in the equation (9). When the torque frequency voltage command value v1q * is obtained by adding the primary frequency ω1 multiplied by the constant σL1 and the excitation current difference (i1d−i1d *), it is output to the coordinate converter 7. .
[0021]
The primary resistance identifying unit 16 identifies the primary resistance R1 according to the equation (15) from the difference (i1d * −i1d) of the excitation current during driving of the induction machine. The correction gain KR used here is selected to be small enough not to respond at the time of transition as described above.
[0022]
[Problems to be solved by the invention]
In such sensorless vector control, motor constants are used for calculations by the speed estimated value calculation unit 11, the primary frequency calculation unit 14, the voltage command value calculation unit 15, and the like. These motor constants are measured by a characteristic test such as primary resistance measurement, no-load test, restraint test or the like before driving, or are automatically measured by a function of the inverter. However, the motor constants, especially the primary resistance and the secondary resistance, change greatly due to the temperature rise of the induction machine accompanying driving, and as a result, a deviation occurs between the actual motor constant and the motor constant used in the control.
[0023]
In particular, since the frequency is low in the low speed region, the term relating to inductance is small and the term relating to resistance becomes dominant, and the influence of the deviation between the primary resistance and the secondary resistance is large. Further, since the heat dissipation effect is small in the low speed region, the temperature rise inside the induction machine is large, and the deviation between the primary resistance and the secondary resistance tends to increase accordingly. As a result, the deviation of the primary resistance causes an error voltage to be superimposed on the primary voltage command value, leading to an estimation error of the primary frequency and a decrease in torque particularly in the low speed region. Further, the deviation of the secondary resistance causes an error of the slip frequency estimation value, resulting in an error in the speed estimation value and a deterioration in speed accuracy. Among these, for the primary resistance, the identification method during driving has been established as described above, and it is possible to correct the primary resistance used in the control, but regarding the secondary resistance, the identification method during driving is It has not yet been established and its correction was impossible.
The present invention has been made in view of the above circumstances, and an object thereof is to provide an induction motor control device that can easily identify a primary resistance and a secondary resistance during driving of an induction machine.
[0024]
[Means for Solving the Problems]
In order to achieve the above object, an induction motor control device of the present invention includes a voltage-type inverter main circuit that outputs a voltage according to an output voltage command value;
After the three-phase to two-phase conversion of the phase current detection value of the induction motor, the excitation current detection value that is a component in the same direction (d-axis direction) as the secondary magnetic flux in the rotating coordinate system that rotates with the primary frequency command value, A coordinate conversion means for separating the torque component current detection value which is a component orthogonal to the secondary magnetic flux (q-axis direction);
Calculate the vector control in the rotation coordinate system from the excitation current command value, speed command value or torque current command value, excitation current detection value, torque current detection value, and motor constant, and use the primary frequency command Vector control calculation means for outputting a value, an excitation voltage command value that is a d-axis direction component, and a torque voltage command value that is a q-axis direction component;
In the region below the predetermined primary frequency, Changes in excitation voltage reference value and torque voltage reference value according to a specific pattern And higher than the primary frequency. Excitation excitation voltage value and identification torque voltage value Short time Voltage adding means for identification to add,
Convert the excitation voltage command value and torque voltage command value after adding the identification excitation voltage value and identification torque voltage value from the rotating coordinate system to the stationary coordinate system, and then perform three-phase to two-phase conversion. A coordinate conversion means for providing an output voltage command value;
Series composition of primary resistance and secondary resistance based on the identification excitation voltage value and the identification torque voltage value, and the change in the excitation current detection value and the torque current detection value when the identification voltage is applied. And a resistance composite value calculating means for calculating a value (claim 1).
[0025]
At this time, the excitation divided voltage command value and the torque divided voltage command value obtained by adding the identification excitation divided voltage value and the identification torque divided voltage value, respectively, the excitation divided current detection value when the identification voltage is applied, and A series composite value of the primary resistance and the secondary resistance can also be calculated from the detected torque current value.
If comprised in this way, the serial composite value of a primary resistance and a secondary resistance can be calculated | required during the drive of an induction machine.
[0026]
In this case, the excitation excitation voltage value for identification and the torque distribution voltage value for identification are determined along the directions of the command voltage vector in which the d-axis direction component and the q-axis direction component are the excitation voltage command value and the torque voltage command value, respectively. It is preferable to add to the excitation voltage division command value and the torque voltage division command value, respectively.
With such a configuration, the direction of the command voltage vector does not change and only the magnitude changes, so that the calculation when adding the identification voltage can be easily performed, the voltage change error is reduced, and a highly accurate series composite value is obtained. Can be obtained.
[0027]
Further, the identification excitation voltage value and the identification torque voltage value are respectively determined along the direction of the detection current vector in which the d-axis direction component and the q-axis direction component are the excitation current detection value and the torque current detection value, respectively. It is preferable to add to the excitation voltage division command value and the torque voltage division command value.
With this configuration, before and after the identification voltage is applied, the direction of the detected current vector does not change and only the magnitude changes, so that the current change error is small, and the command voltage vector and the change in the command voltage vector (identification) The voltage vector) is known as a command value, so that a more accurate series composite value can be obtained.
[0028]
After the output voltage command value is generated from the excitation voltage division command value and the torque voltage division command value in the coordinate conversion means, it is sent to the identification voltage addition means. In the region below the predetermined primary frequency, The output voltage command value changes according to a specific pattern And higher than the primary frequency. The voltage value for identification Short time It is also possible to calculate the series composite value of the primary resistance and the secondary resistance from the identification voltage value and the change in the phase current detection value when the identification voltage is applied in the resistance composite value calculation means. (Claim 2).
At this time, in the resistance composite value calculation means, a series composite value of the primary resistance and the secondary resistance from the output voltage command value to which the identification voltage value is added and the phase current detection value when the identification voltage is applied. Can also be calculated (claim 7).
According to this configuration, since a calculation error due to coordinate conversion does not enter the voltage command value and the current detection value in the calculation of the serial composite value, a more accurate serial composite value can be obtained.
[0029]
After the output voltage command value is generated from the excitation divided voltage command value and the torque divided voltage command value in the coordinate conversion means, the PWM control means forms a PWM waveform to be given to each gate of the voltage type inverter main circuit from the output voltage command value. For identification voltage addition means In the region below the predetermined primary frequency, By changing the pulse width of the PWM waveform according to a specific pattern, the output voltage of the voltage type inverter main circuit Higher frequency than primary frequency Identification voltage Short time It is also possible to calculate the series composite value of the primary resistance and the secondary resistance from the identification voltage value and the change in the phase current detection value when the identification voltage is applied in the resistance composite value calculation means. (Claim 3).
At this time, in the resistance composite value calculation means, a series composite value of the primary resistance and the secondary resistance from the output voltage command value to which the identification voltage value is added and the phase current detection value when the identification voltage is applied. Can also be calculated (claim 8).
With such a configuration, since the PWM waveform can be directly controlled, the identification voltage is applied to the induction machine at a high speed, and the calculation error due to coordinate conversion does not enter the calculation of the series composite value. A composite value can be obtained.
[0030]
Further, secondary resistance identification is performed by calculating the secondary resistance value by subtracting the primary resistance value identified by another means from the series combined value of the primary resistance and the secondary resistance calculated by the above-described resistance composite value calculation means. (Claim 9), constant correction means for correcting the motor constant used in the vector control calculation means based on the serial combined value of the primary resistance and the secondary resistance or the primary resistance value and the secondary resistance value ( (Claim 10), the series combined value of the primary resistance and the secondary resistance, or the primary resistance value and the secondary resistance value are stored in the storage means, and the stored value is read out at the start of the next operation and used in the vector control calculation means. Learning means for correcting the motor constant can be provided (claim 11).
[0031]
If comprised in this way, a secondary resistance value can be identified during the drive of an induction machine (Claim 9), the primary resistance value and secondary resistance value which are used by control, and the actual resistance value (true value) of an induction machine (Claim 10), the speed and torque can be controlled with high accuracy regardless of the temperature change of the induction machine. Further, by providing the learning function, the deviation between the primary resistance value and the secondary resistance value at the start of operation can be reduced, and more stable and highly accurate control can be performed.
[0032]
DETAILED DESCRIPTION OF THE INVENTION
A first embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a block diagram of a control system according to the present embodiment. The same parts as those in FIG. 20 are denoted by the same reference numerals and the description thereof will be omitted.
[0033]
The identification voltage calculation unit 18 generates a pulse-shaped identification voltage for identifying the series combined value of the primary resistance and the secondary resistance when the primary frequency ω1 is in a steady operation state in a sufficiently small region. is there. The identification excitation voltage Δvd and the identification torque voltage Δvq are respectively added to the excitation voltage command value v1d * and the torque voltage command output from the voltage command value calculator 15 by the adder of the voltage addition means 17 for identification. The value is added to the value v1q * and further output to the resistance composite value calculation unit 19.
[0034]
The resistance composite value calculation unit 19 includes the above-described identification excitation voltage Δvd and identification torque voltage Δvq, and the excitation current detection value i1d and torque current of the primary current when these identification voltages are applied to the induction machine. From the change in the detected value i1q, a series combined value of the primary resistance and the secondary resistance is calculated by calculation described later.
The control system, coordinate converters 6 and 7 and PWM control unit 8 shown in FIG. 1 are all configured by a microcomputer serving as control means and its peripheral input / output circuit.
[0035]
Next, the identification principle of the resistance value and the operation of the present embodiment will be described in detail with reference to FIGS. In FIG. 2 showing an equivalent circuit of the induction machine in a steady state, (L1 -M) represents a primary side leakage inductance, and (L2 -M) represents a secondary side leakage inductance. The current im flowing through the mutual inductance M corresponds to the excitation current. The power consumed in the term (R2 / s) obtained by dividing the secondary resistance R2 by the slip s is called the synchronous watt, which is further divided into the copper loss of the secondary winding and the mechanical output. Can be expressed.
[0036]
Here, when the induction machine is in steady operation at a low speed, the term of the primary side leakage inductance (L1 -M) in the equivalent circuit becomes minute and can be ignored. Further, the term (R2 / s) is separated into a secondary resistance R2 which is a term related to the copper loss of the secondary winding and a (1-s) R2 / s which is a term related to the machine output. If the vector sum of voltages induced in the (1-s) R2 / s term and the secondary leakage inductance (L2-M) term is defined as an induced voltage ebk, the equivalent circuit shown in FIG. 2 is shown in FIG. Converted to an equivalent circuit. FIG. 4 shows a vector diagram at this time. The primary voltage vector v1 is equal to the vector sum of the induced voltage ebk, the voltage drop R2 i2 due to the secondary resistance, and the voltage drop R1 i1 due to the primary resistance.
[0037]
In the present invention, a pulse-shaped identification voltage having a narrow time width is applied to the primary voltage, and the resistance value is identified from the primary voltage and the primary current at the time of the application, or a change amount thereof. In this case, since the identification voltage can be regarded as a high-frequency signal, the equivalent circuit shown in FIG. 3 is further converted into an equivalent circuit represented as a high-frequency circuit. In the high-frequency circuit, the exciting current im flowing through the mutual inductance M hardly changes. Therefore, when this current is replaced with a constant current source im and the constant current source is changed to a configuration using an equivalent constant voltage source, FIG. 5 is obtained. Here, the newly appearing constant voltage source eim (= R2 im: where im = i2 -i1) is added to eliminate the exciting current term from the equivalent circuit shown in FIG. 3, and corresponds to the induced voltage. This high-frequency equivalent circuit can be applied only to a high-frequency input voltage during low-speed operation, and is characterized by a circuit configuration in which a primary resistance R1 and a secondary resistance R2 are connected in series to the induced voltages ebk and eim. Have
[0038]
FIG. 6 is a vector diagram showing this high-frequency equivalent circuit. The primary voltage vector v1 is equal to the vector sum of the induced voltages ebk and eim and the voltage drop (R1 + R2) i1 due to the series combined value of the primary resistance and the secondary resistance. . Therefore, the impedance of the induction machine is only the series combined value (R1 + R2) of the primary resistance and the secondary resistance, and the series combined value of the primary resistance and the secondary resistance (R1 + R2) is obtained from the vector calculation of the following equation.
R 1 + R 2 = Δv 1 / Δi 1 (16)
Where Δv 1: change in primary voltage vector (identification voltage vector)
Δi1: Change in primary current vector
[0039]
When the above identification principle is applied to the present embodiment, the voltage command value v1 * () is obtained by the identification voltage adding means 17 when the stationary operation is performed in the primary frequency region sufficiently low so that the leakage inductance of the induction machine is negligible. = Δv1d * + jΔv1q *) and a pulse-like identification voltage value Δv1 (= Δvd + jΔvq) may be added. At this time, if the resistance composite value calculation unit 19 executes the vector calculation of the equation (16) using the identification voltage value Δv1 and the change Δi1 of the primary current before and after the identification voltage value, the primary resistance and the secondary resistance are connected in series. A composite value can be obtained.
[0040]
FIG. 7 shows a vector diagram when an identification voltage is applied. The primary voltage vector v1 ′ after addition of the identification voltage is obtained by adding the identification voltage vector Δv1 having the d-axis component Δvd and the q-axis component Δvq to the primary voltage vector v1 in the steady state before the addition. It represents that the primary current vector i1 in the previous steady state changes to i1 ′ after application.
[0041]
In addition, in the calculation in the resistance composite value calculation unit 19, after applying the identification voltage, taking into account the delay in the rise of the primary current caused by the leakage inductance and the skin effect on the secondary resistance, a certain time after application The change in the primary current is calculated using the primary current detection value after the elapse of time. Further, the application of the identification voltage and the detection of the primary current need to be completed in a short time such that the excitation current and the induced voltages ebk and eim do not change.
[0042]
As described above, according to the present embodiment, when the induction machine is in steady operation at a low speed, a pulse-shaped identification voltage in a short time that can be regarded as a high frequency is applied to the induction machine. In this case, the equivalent circuit of the induction machine is a series connection of the induced voltage, primary resistance and secondary resistance, and the induced voltage does not change for a short time primary voltage change. A series composite value of the primary resistance and the secondary resistance can be calculated from the change in the primary current before and after.
[0043]
Next, a second embodiment of the present invention will be described with reference to FIG. 8 showing an electrical configuration. The same parts as those in FIG. 19 are denoted by the same reference numerals, description thereof is omitted, and only different parts will be described.
The identification voltage calculation unit 21 generates a pulse-shaped identification voltage for identifying the series combined value of the primary resistance and the secondary resistance when the primary frequency ω1 is in a sufficiently small region and in a steady operation state. It is. The identification U-phase voltage Δvu, the identification V-phase voltage Δvv, and the identification W-phase voltage Δvw are respectively outputted from the coordinate converter 7 by the adder of the identification voltage adding means 20. It is added to vu *, V-phase output voltage command value vv *, and W-phase output voltage command value vw *, and is also output to the resistance composite value calculation unit 22.
[0044]
The resistance composite value calculation unit 22 includes the identification voltages Δvu, Δvv, Δvw, and the primary current V-phase current detection value iv, W-phase current detection value iw, when these identification voltages are applied to the induction machine, and A series combined value of the primary resistance and the secondary resistance is calculated from each change amount of the U-phase current detection value iu calculated as-(iv + iw).
[0045]
According to the second embodiment configured as described above, the change amount of the identification voltage vector Δv1 composed of the identification voltage values Δvu, Δvv, Δvw and the primary current vector composed of the phase current detection values iu, iv, iw. Using Δi1, a series composite value of the primary resistance and the secondary resistance can be obtained in accordance with the vector calculation of the equation (16). In this case, unlike the first embodiment, the change Δi1 of the primary current vector used for the calculation is not subjected to the coordinate conversion by the coordinate converter 6, so that the calculation error in the coordinate converter 6 is eliminated. Further, since the identification voltage vector Δv1 is also directly added to the output voltage command value output from the coordinate converter 7 to the PWM control unit 8, there is no calculation error in the coordinate converter 7, and the identification voltage is accurate. Applied to the induction machine. Therefore, the resistance can be identified more accurately.
[0046]
Next, a third embodiment of the present invention will be described with reference to FIG. 9 showing an electrical configuration. The same parts as those in FIG. 19 are denoted by the same reference numerals, and the description thereof is omitted.
When the primary voltage ω1 is in a steady operation state in a region where the primary frequency ω1 is sufficiently small, the identification voltage calculation unit 24 uses the identification voltage for identifying the series combined value of the primary resistance and the secondary resistance to the PWM control unit 25. An instruction signal a1 for instructing generation is output. This instruction signal a1 is also given to the resistance composite value calculator 26 at the same time. When the instruction signal a1 is input, the PWM control unit 25 changes the pulse width of the PWM waveform only during the input period as shown in FIG. That is, the PWM waveform (solid line) output from the PWM control unit 25 in the steady operation state has a cycle Tc (= 1 / fc: fc is a carrier frequency) and a pulse width Pw1. At this time, when the instruction signal a1 for instructing the generation of the identification voltage is input to the PWM control unit 25, the pulse width is changed to Pw2 according to the identification voltage for each carrier as indicated by the broken line in the figure. As a result, since the output voltage of the inverter main circuit 4 changes, the identification voltage can be applied to the induction machine.
[0047]
The resistance composite value calculation unit 26 obtains the instruction signal a1 from the identification voltage calculation unit 24 and generates identification voltages Δvu, Δvv, Δvw applied to the induction machine, and these identification voltages and these identification voltages are generated. From the respective changes in the U-phase current detection value iu calculated as V-phase current detection value iv, W-phase current detection value iw and-(iv + iw) of the primary current when is applied to the induction machine A series composite value of a resistor and a secondary resistor is calculated.
[0048]
According to the present embodiment having the above-described configuration, the identification voltage vector Δv1 composed of the identification voltage values Δvu, Δvv, Δvw indicated by the instruction signal a1 and the primary composed of the phase current detection values iu, iv, iw. By using the change Δi1 of the current vector, a series combined value of the primary resistance and the secondary resistance can be obtained according to the vector calculation of the equation (16). In this case, the primary current vector change Δi1 used for the calculation is not subjected to the coordinate conversion by the coordinate converter 6, so that the calculation error in the coordinate converter 6 is eliminated. Further, since the identification voltage vector Δv1 is generated by directly changing the PWM waveform by the PWM control unit 25, the calculation error in the coordinate converter 7 is eliminated, and the identification voltage is applied to the induction machine at high speed and accurately. The Therefore, the resistance can be identified more accurately.
[0049]
Next, a fourth embodiment of the present invention will be described with reference to FIG. 11 showing a block diagram of the control unit. The same parts as those in FIG. 1 and FIG.
The combined resistance value calculation unit 27 adds the identification excitation voltage Δvd and the identification torque voltage Δvq to the excitation voltage command value v1d * and the torque voltage command value v1q *, respectively, in the identification voltage calculation unit 17. Excitation voltage command value vd *, torque voltage command value vq *, and the excitation current detection value i1d and torque current detection value i1q of the primary current when these identification voltages are applied to the induction machine, A series composite value of the primary resistance and the secondary resistance is calculated.
[0050]
This embodiment is characterized in that the identification calculation is performed using the primary voltage value and the primary current detection value itself, instead of the change in the primary voltage to which the identification voltage is added and the detected primary current. The principle of identifying the serially combined value of the primary resistance and the secondary resistance is as described above with reference to FIGS. 2 to 7. The primary voltage vector to which the identification voltage is added is represented by v1 ′ (= v1 + Δv1), Assuming that the primary current vector detected after the voltage is applied is i1 ′, the series combined value (R1 + R2) of the primary resistance and the secondary resistance can be calculated by the following equation.
R1 + R2 = v1 '/ i1' (17)
[0051]
In this case as well, in the calculation in the resistance composite value calculation unit 27, it is necessary to calculate using the primary current detection value after a certain time has elapsed after applying the identification voltage. Further, the application of the identification voltage and the detection of the primary current need to be completed in a short time such that the values of the excitation current and the induced voltages ebk and eim do not change.
[0052]
According to the fourth embodiment configured as described above, when the induction machine is in steady operation at a low speed, the pulse-shaped identification voltage for a short time that can be regarded as a high-frequency voltage is used as the primary voltage command value. Apply. In this case, the equivalent circuit of the induction machine is a series connection of an induced voltage, a primary resistance and a secondary resistance, and the induced voltage does not change for a short time primary voltage change. A series composite value of the primary resistance and the secondary resistance can be calculated from the subsequent primary current.
[0053]
Next, a fifth embodiment of the present invention will be described with reference to FIG. The same parts as those in FIG. 8 and FIG.
The resistance composite value calculator 28 outputs the U-phase output voltage command value vu *, the V-phase output voltage command value vv *, and the W-phase output voltage command value vw * output from the coordinate converter 7 in the voltage adding means 20 for identification. And the phase output voltage command values vu **, vv **, vw ** after the identification voltages Δvu, Δvv, Δvw are added to each other, and the primary when these identification voltages are applied to the induction machine From the V-phase current detection value iv, the W-phase current detection value iw, and the U-phase current detection value iu calculated as-(iv + iw), the series combined value of the primary resistance and the secondary resistance is calculated. It has become.
[0054]
According to the fifth embodiment configured as described above, the primary voltage vector composed of the output voltage command values vu **, vv ** and vw ** after the addition of the identification voltage value, and the phase current detection value. By using the primary current vector i1 composed of iu, iv and iw, a series combined value of the primary resistance and the secondary resistance can be obtained according to the vector calculation of the equation (17). In this case, as in the second embodiment, the primary current vector i1 used for the calculation is not subjected to the coordinate conversion by the coordinate converter 6, so that the calculation error in the coordinate converter 6 is eliminated. Further, since the identification voltage vector Δv1 is also directly added to the output voltage command value output from the coordinate converter 7 to the PWM control unit 8, there is no calculation error in the coordinate converter 7, and the identification voltage is accurately determined. Applied to induction machine. Therefore, the resistance can be identified more accurately.
[0055]
Next, a sixth embodiment of the present invention will be described with reference to FIG. The same parts as those in FIG. 9 and FIG.
The identification voltage calculation unit 24 outputs an identification voltage generation instruction signal a1 to the PWM control unit 29 when the primary frequency ω1 is in a steady operation state in a sufficiently small region. When the instruction signal a1 is input to the PWM controller 29, the pulse width of the PWM waveform is changed for each carrier in order to apply the identification voltage to the induction machine, and at the same time, a signal relating to the changed pulse width is used as the primary voltage. The signal a2 is output to the resistance composite value calculator 30.
[0056]
The combined resistance value calculation unit 30 uses the primary voltage signal a2 from the PWM control unit 29 to generate induction machine primary voltages vu, vv, vw after addition of identification voltages, and these primary voltages and identification voltages are induced. The primary resistance and secondary resistance of the primary current and the secondary resistance are calculated from the V-phase current detection value iv, the W-phase current detection value iw, and the U-phase current detection value iu calculated as-(iv + iw) when applied to the machine. The series composite value is calculated.
[0057]
According to the present embodiment configured as described above, the primary resistance and the secondary resistance of the primary voltage vector v1 and the primary current vector i1 after the addition of the identification voltage value are calculated according to the vector calculation of the equation (17). A series composite value can be obtained. In this case, as in the third embodiment, the primary current vector i1 used for the calculation is not subjected to the coordinate conversion by the coordinate converter 6, so that the calculation error in the coordinate converter 6 is eliminated. Further, the identification voltage vector Δv1 is generated by directly changing the PWM waveform by the PWM control unit 29, so that the calculation error in the coordinate converter 7 is eliminated and the identification voltage is applied to the induction machine at high speed and accurately. The Therefore, the resistance can be identified more accurately.
[0058]
Next, a seventh embodiment of the present invention will be described with reference to the vector diagram shown in FIG. In this embodiment, the identification voltage generated by the identification voltage calculator 18 in FIGS. 1 and 11 is configured to add the identification voltage to the excitation voltage division command value v1d * and the torque voltage division command value v1q *. The direction of the identification voltage vector Δv1 consisting of the excitation voltage division Δvd and the identification torque voltage division Δvq is determined based on the command consisting of the excitation voltage division command value v1d * and the torque voltage division command value v1q * output from the voltage command value calculator 15. The direction is the same as the direction of the voltage vector v1 *.
[0059]
When such an identification voltage is used, the direction of the command voltage vector before and after the addition does not change and only the magnitude changes. Therefore, vector calculation when adding the identification voltage can be easily performed, and the voltage change error is reduced. Therefore, it is possible to obtain a more accurate series composite value using the equation (16) or the equation (17).
[0060]
Next, an eighth embodiment of the present invention will be described with reference to the vector diagram shown in FIG. In this embodiment, the identification voltage generated by the identification voltage calculator 18 in FIGS. 1 and 11 is configured to add the identification voltage to the excitation voltage division command value v1d * and the torque voltage division command value v1q *. The direction of the identification voltage vector Δv1 composed of the excitation voltage Δvd and the identification torque voltage Δvq is set in the same direction as the direction of the detection current vector i1 consisting of the excitation current detection value i1d and the torque current detection value i1q.
[0061]
When such an identification voltage is used, the direction of the detected current vector does not change and only the magnitude changes, so that the current change error is small, and the change in the command voltage vector or the command voltage vector (identification voltage vector) is the command. Since the value is known in the control device, a more accurate series composite value can be obtained using the equation (16) or (17).
[0062]
Next, a ninth embodiment of the present invention will be described with reference to FIG. 16 showing a block diagram of a secondary resistance identification unit.
In this secondary resistance identification unit, the primary resistance identification unit 16 uses the series combined value (R1 + R2) of the primary resistance and the secondary resistance identified by the above-described equation (17) in the resistance synthesis value calculation unit 27. The secondary resistance value R2 is calculated by subtracting the primary resistance value identified by equation (15). A constant correction means (not shown) corrects the primary resistance value and the secondary resistance value used for the vector control calculation to true values based on the identified primary resistance value and secondary resistance value. Yes.
[0063]
According to the present embodiment, during driving of the induction machine, using the primary resistance value obtained by the already established identification method, and the series combined value of the primary resistance and the secondary resistance obtained by the present invention, A secondary resistance value for which an identification method has not yet been established can be easily obtained. And, since the resistance value used for the vector control calculation is corrected based on the obtained resistance value, high speed accuracy and torque linearity are maintained even if there is a temperature change of the winding accompanying the drive of the induction machine. be able to.
[0064]
Further, a tenth embodiment of the present invention will be described with reference to FIG. 17 showing a block diagram of a resistance identification unit provided with a learning means.
In the present embodiment, during the driving of the induction machine, a primary combined value (R1 + R2) of the primary resistance and the secondary resistance calculated by the resistance combined value calculating unit 27, and the primary resistance identified by the primary resistance identifying unit 16 is used. The value and the secondary resistance value calculated from these values are stored in the memory 31, which is a storage means, in particular, a nonvolatile memory or a volatile memory backed up by a battery. The stored value is read out at the start of the next operation and used for vector control calculation. According to the present embodiment to which such a learning function is added, the deviation of the resistance value at the start of operation can be suppressed to be small, and stable starting and highly accurate and stable control immediately after starting are possible.
[0065]
The present invention is not limited to the embodiments described above and illustrated in the drawings, and the following modifications or expansions are possible.
The pulse-shaped identification voltage applied to the primary voltage of the induction machine may be a French hat-shaped waveform as shown in FIG. This waveform repeats step changes alternately on the negative side, positive side, and negative side around the zero voltage level, and the negative side voltage value is equal to the absolute value of the positive side voltage value, and the negative side voltage. (1) and (3) part: T + T = 2T) and the positive voltage (2) part: 2T.
[0066]
Although not shown, the step change is repeated alternately with the negative side, the positive side, and the negative side around the zero voltage level, and the positive side voltage value is equal to twice the absolute value of the negative side voltage value. Moreover, the waveform may be such that the negative pulse voltage widths (1 and 3) and the positive pulse voltage width (2) are all equal.
[0067]
These identification voltage waveforms have an average voltage of 0, that is, do not include a direct current component, so that changes in excitation current and induced voltage associated with application of the identification voltage can be sufficiently reduced. In addition, since the resistance value can be identified every time the waveform changes step by step, a plurality of calculation results can be obtained by applying the identification voltage once. Can be identified. In this case, the pulse width T is preferably shorter than the time for which the induced voltage changes. However, when the inertia of the load is large and when the induced voltage is accurately known, the pulse width T is widened. be able to.
[0068]
In addition, the detection of the primary current after application of the identification voltage is performed after a certain period of time has elapsed after application in consideration of the effect of the skin effect on leakage inductance and secondary resistance as described above. The final value of the primary current may be predicted using an exponential function or the like, and the resistance value identification calculation may be performed using the predicted value. According to this method, the resistance value can be identified in a shorter time.
[0069]
In the ninth embodiment, as an alternative method for determining the primary resistance value and the secondary resistance value from the series combined value (R1 + R2) of the primary resistance and the secondary resistance, the primary resistance value R1 measured in advance and the secondary resistance value Based on the ratio of the secondary resistance value R2, the series combined value (R1 + R2) of the primary resistance and the secondary resistance may be distributed to each resistance value. In this case, the ratio may be changed according to the speed command value or the load, or an empirical function may be used. As a result, the primary resistance identification unit 16 becomes unnecessary.
[0070]
Furthermore, the user can set an area (refresh enable area) in which the motor constant is allowed to be identified and corrected in advance, and the induction machine is operated in this area, and the rotation speed and steady state are identifiable. After the determination, if identification is possible, it may be configured to automatically start processing including identification voltage application, primary current detection, resistance value identification calculation, and constant correction.
[0071]
The combined value (R1 + R2) of the identified primary resistance and secondary resistance, or the primary resistance value and the secondary resistance value, these resistance values under a predetermined temperature, and the resistance of the primary / secondary winding The temperature rise of the winding, that is, the temperature rise of the induction machine may be calculated from the temperature coefficient and used as an alternative to the temperature sensor.
[0072]
【The invention's effect】
Since this invention is as having demonstrated above, there exist the following effects.
According to the induction motor control device of claim 1 or 4, when the induction machine is operating at a low speed, the equivalent circuit when the high frequency voltage is applied is a series connection of the induced voltage, the primary resistance, and the secondary resistance. Focusing on the fact that it is represented, the voltage adding means for identification in the control device In the region below the predetermined primary frequency, Changes in excitation voltage command value and torque voltage command value output from vector control calculation means according to a specific pattern And higher than the primary frequency. Excitation excitation voltage value and identification torque voltage value Short time In addition, in the resistance composite value calculation means, the identification voltage vector is divided by the change in the primary current vector composed of the excitation current detection value and the torque current detection value at the time of application of the identification voltage. The series composite value of the secondary resistance is calculated (claim 1). Further, in the resistance composite value calculation means, the series composite value is calculated by dividing the primary voltage vector after addition of the identification voltage by the primary current vector when the identification voltage is applied (claim 4). As a result, it is possible to obtain a series composite value of the primary resistance and the secondary resistance even during driving of the induction machine.
[0073]
According to the induction motor control apparatus of claim 2 or 7, after the output voltage command value of each phase is generated from the excitation voltage division command value and the torque voltage division command value in the coordinate conversion means, the identification voltage addition means In the region below the predetermined primary frequency, The output voltage command value changes according to a specific pattern And higher than the primary frequency. The voltage value for identification Short time The series combined value of the primary resistance and the secondary resistance is calculated by adding and dividing the identification voltage vector by the change in the detected current vector consisting of the phase current when the identification voltage is applied in the resistance composite value calculation means. Calculation is performed (claim 2). In the resistance composite value calculation means, the series composite value is calculated by dividing the primary voltage vector after addition of the identification voltage by the primary current vector when the identification voltage is applied (claim 7). As a result, the calculation error due to the coordinate conversion is removed from the primary current vector, and the identification voltage vector is also directly added to the output voltage command value after the coordinate conversion, so that a more accurate resistance can be identified.
[0074]
According to the induction motor control device of claim 3 or 8, the identification voltage adding means In the region below the predetermined primary frequency, By changing the pulse width of the PWM waveform according to a specific pattern, the output voltage of the voltage type inverter main circuit Higher frequency than primary frequency Identification voltage Short time Addition, and dividing the identification voltage vector by the change in the detected current vector when the identification voltage is applied in the resistance composite value calculation means, the series composite value of the primary resistance and the secondary resistance is calculated. (Claim 3). In the resistance composite value calculation means, the series composite value is calculated by dividing the primary voltage vector after addition of the identification voltage by the primary current vector when the identification voltage is applied (claim 8). Therefore, the calculation error due to coordinate transformation is removed from the primary current vector, and the addition of the identification voltage is performed at high speed by directly changing the pulse width of the PWM waveform, so that more accurate resistance identification is possible.
[0075]
According to the induction motor control device of the fifth aspect, since the identification voltage vector is added along the direction of the command voltage vector composed of the excitation voltage division command value and the torque voltage division command value, the direction of the command voltage vector is changed. Only the size changes. Therefore, the calculation for adding the identification voltages can be easily performed, and a highly accurate series composite value can be obtained.
[0076]
According to the induction motor control device of the sixth aspect, since the identification voltage vector is added along the direction of the detection current vector composed of the excitation current detection value and the torque current detection value, before and after the identification voltage is applied. The direction of the detected current vector does not change and only the magnitude changes. Accordingly, the current change error is reduced, and the command voltage vector and the identification voltage vector are known as command values, so that a more accurate series composite value can be obtained.
[0077]
According to the induction motor control device of the ninth aspect, the secondary resistance is obtained by subtracting the primary resistance value identified by another means from the series composite value of the primary resistance and the secondary resistance calculated by the resistance composite value calculation means. The resistance value can be identified.
[0078]
According to the induction motor control device of claim 10, since the motor constant used in the vector control calculation means is corrected based on the series combined value of the primary resistance and the secondary resistance, or the primary resistance value and the secondary resistance value, Regardless of the temperature change of the induction machine, the speed and torque can be controlled with high accuracy and stability.
[0079]
According to the induction motor control device of claim 11, the identified primary resistance and the secondary resistance in series or the primary resistance value and the secondary resistance value are stored in the storage means, and at the start of the next operation, Since the electric motor constant used by the vector control calculation means can be corrected based on the resistance value, stable starting and highly accurate and stable control immediately after starting are possible.
[Brief description of the drawings]
FIG. 1 is a block diagram of a control system showing a first embodiment of the present invention.
FIG. 2 is an equivalent circuit of an induction motor in a steady state.
FIG. 3 is an equivalent circuit of an induction motor using an induced voltage.
FIG. 4 is a vector diagram showing an equivalent circuit of an induction motor using an induced voltage.
FIG. 5 Induction motor high frequency equivalent circuit
FIG. 6 is a vector diagram showing a high-frequency equivalent circuit of an induction motor
FIG. 7 is a vector diagram when an identification voltage is applied.
FIG. 8 is an electrical configuration diagram showing a second embodiment of the present invention.
FIG. 9 is a view corresponding to FIG. 8 showing a third embodiment of the present invention.
FIG. 10 is a diagram showing PWM waveforms in the third embodiment of the present invention.
FIG. 11 is a view corresponding to FIG. 8 showing a fourth embodiment of the present invention.
FIG. 12 is a view corresponding to FIG. 8 showing a fifth embodiment of the present invention.
FIG. 13 is a view corresponding to FIG. 8 showing a sixth embodiment of the present invention.
FIG. 14 is a view corresponding to FIG. 7 showing a seventh embodiment of the present invention.
FIG. 15 is a view corresponding to FIG. 7 showing an eighth embodiment of the present invention.
FIG. 16 is a block diagram of a secondary resistance identification unit in the ninth embodiment of the present invention.
FIG. 17 is a block diagram of a resistance identification unit in a tenth embodiment of the present invention.
FIG. 18 is a diagram showing an example of an identification voltage waveform
FIG. 19 is a view corresponding to FIG.
FIG. 20 is a view corresponding to FIG.
[Explanation of symbols]
4 is an inverter main circuit, 5 is an induction motor, 6 and 7 are coordinate converters, 8, 25 and 29 are PWM control units, 9 is a sensorless vector control unit, 15 is a voltage command value calculation unit, and 16 is a primary resistance identification unit. , 17, 20, 23 are identification voltage adding means, 18, 21, 24 are identification voltage calculation units, and 19, 22, 26 to 28, 30 are resistance composite value calculation units.

Claims (11)

A voltage type inverter main circuit that outputs a voltage according to an output voltage command value;
After the three-phase to two-phase conversion of the phase current detection value of the induction motor, the excitation current detection value that is a component in the same direction (d-axis direction) as the secondary magnetic flux in the rotating coordinate system that rotates with the primary frequency command value, A coordinate conversion means for separating the torque component current detection value which is a component orthogonal to the secondary magnetic flux (q-axis direction);
Perform vector control in the rotating coordinate system from the excitation current command value, speed command value or torque current command value, the excitation current detection value, the torque current detection value, and the motor constant, Vector control calculation means for outputting a primary frequency command value, an excitation voltage division command value that is the d-axis direction component, and a torque voltage division command value that is the q-axis direction component;
In an area below a predetermined primary frequency, the excitation excitation voltage value and the torque identification voltage value that change according to a specific pattern and have a higher frequency than the primary frequency in the excitation voltage division command value and the torque voltage division command value. Voltage adding means for identification for adding each voltage value for a short time ;
Three-phase-two-phase after converting the excitation voltage command value and the torque voltage command value after adding the identification excitation voltage value and the identification torque voltage value from the rotating coordinate system to the stationary coordinate system Coordinate conversion means for converting to the output voltage command value;
The primary resistance and the secondary resistance are determined from the identification excitation voltage value and the identification torque voltage value, and the change in the excitation current detection value and the torque current detection value when the identification voltage is applied. An induction motor control device comprising resistance combined value calculating means for calculating a series combined value. A voltage type inverter main circuit that outputs a voltage according to an output voltage command value;
After the three-phase to two-phase conversion of the phase current detection value of the induction motor, the excitation current detection value that is a component in the same direction (d-axis direction) as the secondary magnetic flux in the rotating coordinate system that rotates with the primary frequency command value, A coordinate conversion means for separating the torque component current detection value which is a component orthogonal to the secondary magnetic flux (q-axis direction);
Perform vector control in the rotating coordinate system from the excitation current command value, speed command value or torque current command value, the excitation current detection value, the torque current detection value, and the motor constant, Vector control calculation means for outputting a primary frequency command value, an excitation voltage division command value that is the d-axis direction component, and a torque voltage division command value that is the q-axis direction component;
Coordinate conversion means for converting the excitation voltage command value and the torque voltage command value from the rotating coordinate system to the stationary coordinate system, and then converting the phase to the output voltage command value by three-phase to two-phase conversion;
In the following area predetermined primary frequency, the identification voltage adding means for adding a short time identifying voltage value as a high frequency compared to the changed and primary frequency according to a specific pattern on the output voltage command value,
Induction motor comprising resistance combined value calculation means for calculating a series combined value of a primary resistance and a secondary resistance from the identification voltage value and a change in the phase current detection value when the identification voltage is applied Control device. A voltage type inverter main circuit that outputs a voltage according to an output voltage command value;
After the three-phase to two-phase conversion of the phase current detection value of the induction motor, the excitation current detection value that is a component in the same direction (d-axis direction) as the secondary magnetic flux in the rotating coordinate system that rotates with the primary frequency command value, A coordinate conversion means for separating the torque component current detection value which is a component orthogonal to the secondary magnetic flux (q-axis direction);
Perform vector control in the rotating coordinate system from the excitation current command value, speed command value or torque current command value, the excitation current detection value, the torque current detection value, and the motor constant, Vector control calculation means for outputting a primary frequency command value, an excitation voltage division command value that is the d-axis direction component, and a torque voltage division command value that is the q-axis direction component;
Coordinate conversion means for converting the excitation voltage command value and the torque voltage command value from the rotating coordinate system to the stationary coordinate system, and then converting the phase to the output voltage command value by three-phase to two-phase conversion;
PWM control means for forming a PWM waveform to be given to each gate of the voltage type inverter main circuit from the output voltage command value;
By changing the pulse width of the PWM waveform according to a specific pattern in a region below a predetermined primary frequency, the output voltage of the voltage-type inverter main circuit is changed to an identification voltage having a higher frequency than the primary frequency for a short time. Voltage adding means for identification to add,
Induction motor comprising resistance combined value calculation means for calculating a series combined value of a primary resistance and a secondary resistance from the identification voltage value and a change in the phase current detection value when the identification voltage is applied Control device. A voltage type inverter main circuit that outputs a voltage according to an output voltage command value;
After the three-phase to two-phase conversion of the phase current detection value of the induction motor, the excitation current detection value that is a component in the same direction (d-axis direction) as the secondary magnetic flux in the rotating coordinate system that rotates with the primary frequency command value, A coordinate conversion means for separating the torque component current detection value which is a component orthogonal to the secondary magnetic flux (q-axis direction);
Perform vector control in the rotating coordinate system from the excitation current command value, speed command value or torque current command value, the excitation current detection value, the torque current detection value, and the motor constant, Vector control calculation means for outputting a primary frequency command value, an excitation voltage division command value that is the d-axis direction component, and a torque voltage division command value that is the q-axis direction component;
In an area below a predetermined primary frequency, the excitation excitation voltage value and the torque identification voltage value that change according to a specific pattern and have a higher frequency than the primary frequency in the excitation voltage division command value and the torque voltage division command value. Voltage adding means for identification for adding each voltage value for a short time ;
Three-phase-two-phase after converting the excitation voltage command value and the torque voltage command value after adding the identification excitation voltage value and the identification torque voltage value from the rotating coordinate system to the stationary coordinate system Coordinate conversion means for converting to the output voltage command value;
Excitation voltage command value and torque voltage command value obtained by adding the identification excitation voltage value and the identification torque voltage value, and the excitation current detection value and torque when the identification voltage is applied. An induction motor control device comprising resistance combined value calculation means for calculating a series combined value of a primary resistance and a secondary resistance from a divided current detection value.   The d-axis direction component and the q-axis direction component are respectively converted into the excitation excitation voltage value for identification and the torque distribution voltage value for identification along the direction of the command voltage vector, which is the excitation voltage division command value and the torque division voltage command value, respectively. The induction motor control device according to claim 1 or 4, wherein the voltage is added to the voltage command value and the torque divided voltage command value.   The d-axis direction component and the q-axis direction component are respectively converted into the excitation excitation voltage value for identification and the torque distribution voltage value for identification along the direction of the detection current vector in which the current detection value and the current detection value of the torque are respectively detected. The induction motor control device according to claim 1 or 4, wherein the voltage is added to the voltage command value and the torque divided voltage command value. A voltage type inverter main circuit that outputs a voltage according to an output voltage command value;
After the three-phase to two-phase conversion of the phase current detection value of the induction motor, the excitation current detection value that is a component in the same direction (d-axis direction) as the secondary magnetic flux in the rotating coordinate system that rotates with the primary frequency command value, A coordinate conversion means for separating the torque component current detection value which is a component orthogonal to the secondary magnetic flux (q-axis direction);
Perform vector control in the rotating coordinate system from the excitation current command value, speed command value or torque current command value, the excitation current detection value, the torque current detection value, and the motor constant, Vector control calculation means for outputting a primary frequency command value, an excitation voltage division command value that is the d-axis direction component, and a torque voltage division command value that is the q-axis direction component;
Coordinate conversion means for converting the excitation voltage command value and the torque voltage command value from the rotating coordinate system to the stationary coordinate system, and then converting the phase to the output voltage command value by three-phase to two-phase conversion;
In the following area predetermined primary frequency, the identification voltage adding means for adding a short time identifying voltage value as a high frequency compared to the changed and primary frequency according to a specific pattern on the output voltage command value,
Resistive composite value calculation means for calculating a series composite value of a primary resistance and a secondary resistance from the output voltage command value to which the identification voltage value is added and the phase current detection value when the identification voltage is applied And an induction motor control device. A voltage type inverter main circuit that outputs a voltage according to an output voltage command value;
After the three-phase to two-phase conversion of the phase current detection value of the induction motor, the excitation current detection value that is a component in the same direction (d-axis direction) as the secondary magnetic flux in the rotating coordinate system that rotates with the primary frequency command value, A coordinate conversion means for separating the torque component current detection value which is a component orthogonal to the secondary magnetic flux (q-axis direction);
Perform vector control in the rotating coordinate system from the excitation current command value, speed command value or torque current command value, the excitation current detection value, the torque current detection value, and the motor constant, Vector control calculation means for outputting a primary frequency command value, an excitation voltage division command value that is the d-axis direction component, and a torque voltage division command value that is the q-axis direction component;
Coordinate conversion means for converting the excitation voltage command value and the torque voltage command value from the rotating coordinate system to the stationary coordinate system, and then converting the phase to the output voltage command value by three-phase to two-phase conversion;
PWM control means for forming a PWM waveform to be given to each gate of the voltage type inverter main circuit from the output voltage command value;
By changing the pulse width of the PWM waveform according to a specific pattern in a region below a predetermined primary frequency, the output voltage of the voltage-type inverter main circuit is changed to an identification voltage having a higher frequency than the primary frequency for a short time. Voltage adding means for identification to add,
Resistive composite value calculation means for calculating a series composite value of a primary resistance and a secondary resistance from the output voltage command value to which the identification voltage value is added and the phase current detection value when the identification voltage is applied And an induction motor control device.   Claims comprising secondary resistance identification means for calculating a secondary resistance value by subtracting a primary resistance value identified by another means from a series composite value of a primary resistance and a secondary resistance calculated from the resistance composite value calculation means. Item 9. The induction motor control device according to any one of Items 1 to 8.   The constant correction means which corrects the motor constant used by the vector control calculation means based on the series combined value of the primary resistance and the secondary resistance, or the primary resistance value and the secondary resistance value. The induction motor control apparatus described.   The series combined value of the primary resistance and the secondary resistance, or the primary resistance value and the secondary resistance value are stored in the storage means, and the stored value is read out at the start of the next operation to correct the motor constant used in the vector control calculation means. The induction motor control device according to claim 1, further comprising learning means.

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