JP3528475B2 - Active filter for power - Google Patents
Active filter for powerInfo
- Publication number
- JP3528475B2 JP3528475B2 JP29827096A JP29827096A JP3528475B2 JP 3528475 B2 JP3528475 B2 JP 3528475B2 JP 29827096 A JP29827096 A JP 29827096A JP 29827096 A JP29827096 A JP 29827096A JP 3528475 B2 JP3528475 B2 JP 3528475B2
- Authority
- JP
- Japan
- Prior art keywords
- harmonic
- amplitude
- current
- phase
- load
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E40/00—Technologies for an efficient electrical power generation, transmission or distribution
- Y02E40/20—Active power filtering [APF]
Landscapes
- Control Of Electrical Variables (AREA)
- Power Conversion In General (AREA)
- Inverter Devices (AREA)
- Supply And Distribution Of Alternating Current (AREA)
Description
【発明の詳細な説明】
【０００１】
【発明の属する技術分野】本発明は、電力系統に生ずる
高調波を吸収する電力用アクティブフィルタに関するも
のである。
【０００２】
【従来の技術】電力用アクティブフィルタ（ＡＦ）は負
荷電流の高調波成分を検出してこれを電流指令として高
調波成分を打ち消すようにインバータの出力電流を制御
する。
【０００３】ＡＦの制御には図３に示すようなｐ−ｑ演
算法が多く用いられている。これは電流検出器ＣＴLで
検出した３相の負荷電流ＩLを電源電圧位相で座標変換
する３相２相変換回路３１でｐ−ｑ軸電流Ｉｐ，Ｉｑに
変換し、ハイパスフィルタ３３，３４でその交流分を検
出し、２相３相変換回路３５で３相に変換して３相の高
調波分電流を得、これを電流指令値Ｉｈ＊としてインバ
ータ２を制御している。
【０００４】このｐ−ｑ演算法の他に図４に示すような
バンドパスフィルタ方式がある。これは電流検出器ＣＴ
Lで検出した負荷電流ＩLを２次〜ｎ次高調波をそれぞれ
通す２次〜ｎ次バンドパスフィルタ４１2〜４１nを用い
てそれぞれ２次〜ｎ次高調波成分を検出し、加算器４２
で加算して高調波分電流とし、これを電流指令値Ｉｈ＊
としてインバータ２を制御するものである。
【０００５】
【発明が解決しようとする課題】ところで、上記図３の
ｐ−ｑ演算法は、高調波成分を一括し検出して制御する
ため各次数に分けて細かく制御することができない。ま
た、図４のバンドパスフィルタ方式は各次高調波成分を
それぞれ各バンドパスフィルタにより検出しているの
で、各次数に分離することは可能であるが、補償しよう
とする次数分のハイパスフィルタ回路が必要となり、ま
た分離した特性がフィルタの回路定数によって決まって
しまう欠点がある。
【０００６】本発明は、従来のこのような問題点に鑑み
てなされたものであり、その目的とするところは、次数
分の回路を用いることなく、各次高調波の振幅及び位相
を細かく制御することができる電力用アクティブフィル
タを提供することにある。
【０００７】
【課題を解決するための手段】本発明は、負荷電流信号
から補償電流指令値を求めてインバータを制御して系統
に補償電流を出力する電力用アクティブフィルタにおい
て、負荷電流信号及び電源電流信号をそれぞれフーリエ
解析する第１、第２の高速フーリエ変換演算回路と、こ
の第１、第２の高速フーリエ変換演算回路の各フーリエ
解析データをそれぞれ演算して負荷電流高調波及び電源
電流高調波の各次成分の振幅，位相データを求める第
１、第２のディジタルフィルタ演算回路と、この第１、
第２のディジタルフィルタ演算回路で分離された負荷電
流高調波及び電源高調波の各次成分の振幅，位相データ
を比較して負荷電流高調波と電源高調波の伝達特性を求
める伝達特性演算回路と、この伝達特性演算回路で求め
られた伝達特性に基づいて負荷電流高調波の振幅及び位
相データを調整する振幅・位相調整回路と、この調整回
路で調整された負荷電流の各次高調波の振幅及び位相デ
ータを合成して前記補償電流指令値を求める各次高調波
合成回路とを備え、負荷高調波電流と電源高調波電流の
振幅特性より、電源側の高調波成分が負荷側のその成分
よりも大きい場合は、振幅・位相調整回路において、そ
の補償成分の振幅や位相を上記振幅特性が最小になるよ
うに調整し、各次高調波合成回路にてその他の正常な高
調波成分と合成して補償電流値を出力することを特徴と
する。
【０００８】
【発明の実施の形態】
実施の形態１
図１にアクティブフィルタの制御ブロックを示す。同図
において、１はアクティブフィルタ（ＡＦ）、２は系統
に出力するＡＦのインバータ、３は負荷電流検出器ＣＴ
Lで検出した負荷電流ＩLをフーリエ解析するＦＦＴ（高
速フーリエ変換）演算回路、５はフーリエ解析されたデ
ータから負荷電流の各次数成分の振幅及び位相データを
得るディジタルフィルタ演算回路、９はそのデータを合
成してインバータ２へ補償電流指令値Ｉｈ＊を出力する
各次高調波合成回路である。
【０００９】本発明は、負荷電流ＩLをＦＦＴ演算回路
３でフーリエ解析し、ディジタルフィルタ演算回路５で
フィルタ演算して負荷電流高調波の各次成分の振幅及び
位相データを求める。このため各次成分の振幅及び位相
情報は完全に分離できる。
【００１０】この分離された各次成分の振幅位相データ
を基に各次高調波合成回路９で補償しようとする各次成
分のデータを合成して補償電流指令値Ｉｈ＊得る。した
がって、ＡＦは負荷電流の高調波を次数毎にきめ細かに
抑制することが可能となる。
【００１１】実施の形態２
図２アクティブフィルタ（ＡＦ）の制御ブロックの他の
例を示す。なお、前記図１に示したものと同一構成部分
は、同一符号を付してその重複する説明を省略する。
【００１２】図２において、４は電源電流検出器ＣＴS
で検出した電源電流ＩSをフーリエ解析するＦＦＴ演算
回路、６はそのフーリエ解析されたデータから負荷電流
の各次数成分の振幅及び位相データを得るディジタルフ
ィルタ演算回路、７はディジタルフィルタ演算回路４及
び６からの同時検出の負荷電流ＩL及び電源電流ＩSの高
調波の振幅及び位相データを比較して負荷高調波と電源
高調波の伝達特性を求める伝達特性演算回路である。
【００１３】８はディジタルフィルタ演算回路５からの
負荷電流高調波の振幅及び位相データを上記負荷高調波
と電源高調波の伝達特性で調整する振幅・位相調整回
路、９はこの調整された負荷電流の各次高調波の振幅及
び位相データを合成してインバータ２へ補償電流指令値
Ｉｈ＊を出力する各次高調波合成回路である。
【００１４】本発明は、負荷電流ＩL及び電源電流ＩSを
同時に検出し、それぞれ高速フーリエ変換回路３及び５
とディジタルフィルタ演算回路４及び６で電流ＩL，ＩS
の高調波を各次数成分に分離し、伝達特性演算回路７で
比較して負荷電流高調波と電源電流高調波の伝達特性を
求め、振幅・位相調整回路８でこの伝達特性に基づいて
フィルタ演算回路５からの分離された負荷電流高調波の
各次成分の振幅及び位相データを調整する。例えば、負
荷高調波電流と電源高調波電流の振幅比（振幅特性）よ
り、電源側の成分が負荷側の成分よりも大きい場合は、
その成分がアクティブフィルタの動作にも関わらず拡大
されていることになる。（系統共振現象）従って、振
幅，位相調整回路８においてその補償成分の振幅や位相
を上記振幅特性が最小になるように調整し、後段の各次
高調波合成回路９にてその他の正常な高調波成分（振幅
特性が拡大傾向にない成分）と合成して補償電流値Ｉｈ
＊を出力すれば高調波の拡大を防止することができる。
即ち、アクティブフィルタは、系統の特性に見合った最
適な補償特性を得ることが可能となる。（系統診断機
能）
【００１５】
【発明の効果】本発明は、上述のとおり構成されている
ので、次に記載する効果を奏する。
【００１６】（１）補償しようとする各次高調波の振幅
及び位相を細かく制御することが可能となる。
【００１７】（２）負荷電流と電源電流の検出を同時に
行い系統の伝達特性の診断による最適な補償特性が得ら
れる。Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power active filter for absorbing harmonics generated in a power system. 2. Description of the Related Art An active power filter (AF) detects a harmonic component of a load current and uses the detected component as a current command to control an output current of an inverter so as to cancel the harmonic component. For controlling the AF, a pq calculation method as shown in FIG. 3 is often used. That is, the three-phase load current I L detected by the current detector C T L is converted into p-q axis currents I p and I q by a three-phase two-phase conversion circuit 31 that performs coordinate conversion with the power supply voltage phase, and the high-pass filters 33 and 34. The two-phase / three-phase conversion circuit 35 converts the alternating current into three phases to obtain a three-phase harmonic current, which is used as a current command value Ih * to control the inverter 2. In addition to the pq operation method, there is a band pass filter method as shown in FIG. This is the current detector CT
The second to n-th order harmonic components are detected by using the second to n-th order band-pass filters 41 2 to 41 n that pass the second to n-th order harmonics of the load current I L detected by L , respectively. 42
To obtain a harmonic component current, which is referred to as a current command value Ih *.
To control the inverter 2. In the pq operation method shown in FIG. 3, since harmonic components are collectively detected and controlled, fine control cannot be performed for each order. In the band-pass filter system shown in FIG. 4, since each higher-order harmonic component is detected by each band-pass filter, it is possible to separate the higher-order harmonic components into the respective orders. However, a high-pass filter circuit for the order to be compensated is used. And there is a disadvantage that the separated characteristics are determined by the circuit constant of the filter. SUMMARY OF THE INVENTION The present invention has been made in view of such conventional problems, and has as its object to finely control the amplitude and phase of each higher harmonic without using circuits of the same order. Active fill for power can
It is to provide the data. [0007] The present invention provides a load current signal.
From the compensation current command value to control the inverter
Active power filter that outputs compensation current to
Fourier load current signal and power supply current signal respectively.
First and second fast Fourier transform operation circuits to be analyzed;
Of the first and second fast Fourier transform operation circuits of
Analyze the analysis data to calculate the load current harmonic and power
Find the amplitude and phase data of each order component of the current harmonic
A first and second digital filter operation circuit;
The load voltage separated by the second digital filter operation circuit
Amplitude and phase data of each harmonic component of current harmonics and power supply harmonics
To determine the transfer characteristics of the load current harmonic and the power supply harmonic.
Transfer characteristic calculation circuit and the transfer characteristic calculation circuit
The amplitude and position of load current harmonics
Amplitude / phase adjustment circuit for adjusting phase data, and this adjustment circuit
The amplitude and phase data of each harmonic of the
Harmonics for obtaining the compensation current command value by combining
A synthesis circuit is provided, and the load harmonic current and the power supply harmonic current are
From the amplitude characteristics, the harmonic component on the power supply side is
If it is larger than that, the amplitude / phase adjustment circuit
The amplitude and phase of the compensating component
And adjust other normal high
The feature is that the compensation current value is output by combining with the harmonic component.
I do. Embodiment 1 FIG. 1 shows a control block of an active filter. In the figure, reference numeral 1 denotes an active filter (AF), 2 denotes an AF inverter for outputting to a system, and 3 denotes a load current detector CT.
FFT (Fast Fourier Transform) arithmetic circuit for performing Fourier analysis of load current I L detected by L , digital filter arithmetic circuit for obtaining amplitude and phase data of each order component of load current from data subjected to Fourier analysis, 9 Each harmonic synthesis circuit combines data and outputs a compensation current command value Ih * to the inverter 2. According to the present invention, the load current IL is subjected to Fourier analysis by the FFT operation circuit 3, and the digital filter operation circuit 5 performs a filter operation to obtain the amplitude and phase data of each order component of the load current harmonic. Therefore, the amplitude and phase information of each next component can be completely separated. Based on the separated amplitude and phase data of each of the next-order components, data of each of the next-order components to be compensated by each of the higher-order harmonic synthesis circuits 9 is synthesized to obtain a compensation current command value Ih *. Therefore, the AF can finely suppress the harmonics of the load current for each order. Embodiment 2 FIG. 2 shows another example of the control block of the active filter (AF). The same components as those shown in FIG. 1 are denoted by the same reference numerals, and the description thereof will not be repeated. In FIG. 2, reference numeral 4 denotes a power supply current detector CT S
In FFT calculation circuit for Fourier analysis of the power current I S detected, 6 digital filter operation circuit for obtaining an amplitude and phase data of each order component of the load current from the Fourier analysis data, 7 digital filter operation circuit 4 and a load current I L and the power supply current I transfer characteristic calculation circuit for comparing the amplitude and phase data determine the transfer characteristic of the load harmonics and line harmonics of the harmonic of S simultaneous detection of six. Reference numeral 8 denotes an amplitude / phase adjusting circuit for adjusting the amplitude and phase data of the load current harmonic from the digital filter operation circuit 5 based on the transfer characteristics of the load harmonic and the power supply harmonic, and 9 denotes the adjusted load current. , And outputs the compensation current command value Ih * to the inverter 2 by combining the amplitude and phase data of each harmonic. According to the present invention, the load current IL and the power supply current IS are simultaneously detected, and the fast Fourier transform circuits 3 and 5 are respectively detected.
And the digital filter operation circuits 4 and 6, the currents I L and I S
Are separated into respective order components, and the transfer characteristic calculation circuit 7 compares the harmonics to obtain the transfer characteristics of the load current harmonic and the power supply current harmonic. The amplitude / phase adjustment circuit 8 calculates the filter based on the transfer characteristics. The amplitude and phase data of each component of the load current harmonic separated from the circuit 5 is adjusted. For example, according to the amplitude ratio (amplitude characteristic) of the load harmonic current and the power supply harmonic current, when the component on the power supply side is larger than the component on the load side,
That component is expanded in spite of the operation of the active filter. (System Resonance Phenomenon) Therefore, the amplitude and phase of the compensating component are adjusted in the amplitude and phase adjusting circuit 8 so that the amplitude characteristics are minimized. Compensating current value Ih by combining with a wave component (a component whose amplitude characteristic does not tend to expand)
If * is output, the expansion of harmonics can be prevented.
That is, the active filter can obtain an optimal compensation characteristic corresponding to the characteristic of the system. (System Diagnosis Function) The present invention is configured as described above, and has the following effects. (1) The amplitude and phase of each higher harmonic to be compensated can be finely controlled. (2) Detecting the load current and the power supply current at the same time and obtaining the optimum compensation characteristics by diagnosing the transmission characteristics of the system.
【図面の簡単な説明】
【図１】実施の形態１にかかるアクティブフィルタの制
御ブロック図。
【図２】実施の形態２にかかるアクティブフィルタの制
御ブロック図。
【図３】従来例にかかるアクティブフィルタの制御ブロ
ック図。
【図４】他の従来例にかかるアクティブフィルタの制御
ブロック図。
【符号の説明】
１…アクティブフィルタ（ＡＦ）
２…インバータ
３，５…ＦＦＴ（高速フーリエ変換）演算回路
４，６…ディジタルフィルタ演算回路
７…伝達特性演算回路
８…振幅・位相調整回路
９…各次高調波合成回路
３１…３相２相変換回路
３３，３４…ハイパスフィルタ
３５…２相３相変換回路
４１2〜４１n…２次〜ｎ次バンドパスフィルタBRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a control block diagram of an active filter according to a first embodiment. FIG. 2 is a control block diagram of an active filter according to a second embodiment. FIG. 3 is a control block diagram of an active filter according to a conventional example. FIG. 4 is a control block diagram of an active filter according to another conventional example. [Description of Signs] 1 Active filter (AF) 2 Inverter 3 5 FFT (fast Fourier transform) operation circuit 4 6 Digital filter operation circuit 7 Transfer characteristic operation circuit 8 Amplitude / phase adjustment circuit 9 Each harmonic synthesis circuit 31... Three-phase two-phase conversion circuits 33 and 34. High-pass filter 35... Two-phase three-phase conversion circuits 41 2 to 41 n .
───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.7 識別記号 ＦＩ Ｈ０２Ｍ 7/48 Ｈ０２Ｍ 7/48 Ｅ ──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. 7 identification code FI H02M 7/48 H02M 7/48 E
Claims (1)
てインバータを制御して系統に補償電流を出力する電力
用アクティブフィルタにおいて、負荷電流信号及び電源電流信号をそれぞれフーリエ解析
する第１、第２の高速フーリエ変換演算回路と、 この第１、第２の高速フーリエ変換演算回路の各フーリ
エ解析データをそれぞれ演算して負荷電流高調波及び電
源電流高調波の各次成分の振幅，位相データを求める第
１、第２のディジタルフィルタ演算回路と、 この第１、第２のディジタルフィルタ演算回路で分離さ
れた負荷電流高調波及び電源高調波の各次成分の振幅，
位相データを比較して負荷電流高調波と電源高調波の伝
達特性を求める伝達特性演算回路と、 この伝達特性演算回路で求められた伝達特性に基づいて
負荷電流高調波の振幅及び位相データを調整する振幅・
位相調整回路と、 この調整回路で調整された負荷電流の各次高調波の振幅
及び位相データを合成して前記補償電流指令値を求める
各次高調波合成回路とを備え、 負荷高調波電流と電源高調波電流の振幅特性より、電源
側の高調波成分が負荷側のその成分よりも大きい場合
は、振幅・位相調整回路において、その補償成分の振幅
や位相を上記振幅特性が最小になるように調整し、各次
高調波合成回路にてその他の正常な高調波成分と合成し
て補償電流値を出力する ことを特徴とする電力用アクテ
ィブフィルタ。(57) In the Patent Claims 1 The active filter power for outputting a compensation current to the system by controlling the inverter seeking compensation current command value from the load current signal, the load current signal and the source current signal To the Fourier analysis
First and second fast Fourier transform operation circuits, and the respective Fourier transform circuits of the first and second fast Fourier transform operation circuits.
D) Calculate the analysis data to calculate load current harmonics and
For obtaining the amplitude and phase data of each order component of the source current harmonic
The first and second digital filter operation circuits are separated from each other by the first and second digital filter operation circuits.
Amplitude of each component of load current harmonic and power supply harmonic,
Compare the phase data and compare the transfer of load current harmonic and power supply harmonic.
Transfer characteristic calculation circuit for determining the transfer characteristic, and the transfer characteristic calculated based on the transfer characteristic calculated by the transfer characteristic calculation circuit.
Adjust the amplitude and phase data of the load current harmonic.
Phase adjustment circuit and amplitude of each higher harmonic of load current adjusted by this adjustment circuit
And the compensating current command value by combining the phase data
Each of the higher harmonic synthesis circuits is provided, and based on the amplitude characteristics of the load harmonic current and the power supply harmonic current,
If the harmonic component on the load side is larger than that component on the load side
Is the amplitude of the compensation component in the amplitude / phase adjustment circuit.
And phase so that the above amplitude characteristics are minimized.
The harmonics are combined with other normal harmonics by the harmonics synthesis circuit.
Power actuating device that outputs a compensation current value
Active filter .
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP29827096A JP3528475B2 (en) | 1996-11-11 | 1996-11-11 | Active filter for power |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP29827096A JP3528475B2 (en) | 1996-11-11 | 1996-11-11 | Active filter for power |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH10145972A JPH10145972A (en) | 1998-05-29 |
| JP3528475B2 true JP3528475B2 (en) | 2004-05-17 |
Family
ID=17857471
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP29827096A Expired - Lifetime JP3528475B2 (en) | 1996-11-11 | 1996-11-11 | Active filter for power |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3528475B2 (en) |
Families Citing this family (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1305195C (en) * | 2003-06-09 | 2007-03-14 | 清华大学 | Active power filtering method with inversing capacitor regulation and branch impendance controlled decoupling |
| ES2233193B1 (en) * | 2003-11-18 | 2006-03-16 | Enertron, S.L. | ACTIVE FILTER TO BE USED IN A NETWORK WITH A NON-LINEAR LOAD. |
| JP4766005B2 (en) * | 2007-06-07 | 2011-09-07 | 株式会社明電舎 | Harmonic current compensator |
| JP2009213322A (en) * | 2008-03-06 | 2009-09-17 | Yanmar Co Ltd | Distributed power supply system |
| JP2010187521A (en) * | 2009-01-16 | 2010-08-26 | Mitsubishi Electric Corp | Motor drive controller, compressor, blower, air conditioner and refrigerator or freezer |
| JP4937281B2 (en) * | 2009-01-16 | 2012-05-23 | 三菱電機株式会社 | Motor drive control device, compressor, blower, air conditioner, refrigerator or freezer |
| JP5560730B2 (en) * | 2009-05-13 | 2014-07-30 | 株式会社明電舎 | Power converter control method, uninterruptible power supply, parallel sag compensator |
| JP5922869B2 (en) * | 2011-01-18 | 2016-05-24 | ダイキン工業株式会社 | Power converter |
| JP6145300B2 (en) | 2013-05-01 | 2017-06-07 | 東芝機械株式会社 | Inverter device and inverter generator |
| CN104635140A (en) * | 2014-12-29 | 2015-05-20 | 国家电网公司 | Low-voltage active power filter testing device and testing method thereof |
| CN104833853B (en) * | 2015-05-14 | 2017-08-11 | 电子科技大学 | A kind of adaptive sliding window DFT harmonic detecting methods of frequency |
-
1996
- 1996-11-11 JP JP29827096A patent/JP3528475B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH10145972A (en) | 1998-05-29 |
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