CN101170282A - Inverter current detecotr - Google Patents
Inverter current detecotr Download PDFInfo
- Publication number
- CN101170282A CN101170282A CNA2007101022031A CN200710102203A CN101170282A CN 101170282 A CN101170282 A CN 101170282A CN A2007101022031 A CNA2007101022031 A CN A2007101022031A CN 200710102203 A CN200710102203 A CN 200710102203A CN 101170282 A CN101170282 A CN 101170282A
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- CN
- China
- Prior art keywords
- inverter
- current
- detecotr
- reactor
- voltage
- 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.)
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Classifications
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
- G01R19/0092—Arrangements for measuring currents or voltages or for indicating presence or sign thereof measuring current only
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
- G01R19/175—Indicating the instants of passage of current or voltage through a given value, e.g. passage through zero
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
- H02P27/00—Arrangements or methods for the control of AC motors characterised by the kind of supply voltage
- H02P27/04—Arrangements or methods for the control of AC motors characterised by the kind of supply voltage using variable-frequency supply voltage, e.g. inverter or converter supply voltage
- H02P27/06—Arrangements or methods for the control of AC motors characterised by the kind of supply voltage using variable-frequency supply voltage, e.g. inverter or converter supply voltage using dc to ac converters or inverters
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- 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
- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B70/00—Technologies for an efficient end-user side electric power management and consumption
- Y02B70/10—Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes
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- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Inverter Devices (AREA)
Abstract
The invention is used for detecting the input current of an inverter used for driving a motor. The proposal of the invention is to detect the voltage connected to the two ends of a reactor positioned at the power supply end for improving the power factor, thereby detecting the current inputted to the power supply end of the inverter. Therefore, the invention provides an inverter current detection device. The inverter converts the common power supply into DC through a rectifier and a smoothing capacitor, and transfers the converted DC into a three-phase AC power supply with a necessary frequency so as to drive the motor. The invention is characterized by comprising a reactor connected with one side of the power supply end and used for improving the power factor of the inverter; a current converting unit for detecting the voltages of the two ends of the reactor and converting the voltages into currents; and a control part for detecting the input current of the inverter according to the size of the converted currents.
Description
Technical field
The present invention relates to a kind of inverter current detecotr of drive motors that be used to detect with the input current of inverter.
Background technology
Usually, inverter is that direct current is converted to three-phase alternating current (U, V, power-converting device W) with any variable frequency.Because this device has energy-conservation, as to be easy to control power output characteristic, therefore be used for driving the motor of electric equipment products such as washing machine, refrigerator, air conditioner more and more.
This inverter is because the maximum permissible power of rated voltage and rated current is defined, thereby when input surpasses voltage, the electric current of rated voltage or rated current, inverter is understood can't operate as normal or break down.Thus, for protection inverter when the electric current of being imported is non-rated current, the various devices of The real time measure input current of inverter size have been developed in succession.
As the one example, as shown in Figure 1, inverter loop comprises: the interchange of power supply 20 commonly used is carried out full-wave rectification and the rectifier 22 exported; Be positioned at described rectifier 22 rear ends and improve the reactor L (reactor) of power factor (PF); The voltage of described rectifier 22 outputs is carried out advection and is transformed to the smmothing capacitor (smoothing condenser) 24 of direct current; The direct voltage of described smmothing capacitor 24 being exported by pulse width modulation (PWM) converts the inverter 26 that the interchange with any variable frequency comes drive motors 28 to; Output offers the pattern of the pwm signal of described inverter 26, by the control part 32 of inverter driving portion 30 control inverters 26.In order to detect the input current of inverter 26, current transformer (CT: hereinafter referred to as current transformer) is connected to power end one side of power supply 20 commonly used, and pass through resistance 40 in rectifier 42 rectifications, the AC signal that produces in secondary winding one side of current transformer (CT), the signal of rectification is measured electric current through the low pass filter of being made up of smmothing capacitor 44 and resistance 46 (LPF), thereby measures the input current of the power end in the inverter.
Yet, this existing drive motors is used the amperometric determination loop of inverter, for the input current that detects inverter 26 need make Current Transformer, this not only causes manufacturing cost to rise, and,, in order to handle the detected current signal of current transformer, need to be provided with the redundant mesh of the low pass filter (LPF) that constitutes by rectifier 42, smmothing capacitor 44 and resistance 46, therefore have the shortcoming of loop complexity.
Summary of the invention
The present invention proposes in order to solve aforesaid problem, its purpose is that the not pattern of wants is used to detect the complicated loop of input current, but detect is the both end voltage of improving the reactor of power factor (PF), thereby a kind of inverter input current detecting device that can detect input current of inverter is provided.
To achieve these goals, the invention provides a kind of inverter current detecotr, it is direct current that this inverter will be used power source conversion always according to rectifier and smmothing capacitor, with the DC converting of this conversion is that 3 cross streams power supplys of expected frequency come drive motors, it is characterized in that comprising: be connected to power end one side with the reactor that is used to improve described inverter power factor, detect described reactor both end voltage and be converted into electric current current converter, and detect the control part of the input current of described inverter according to the size of current of conversion.
And, described reactor, its characteristics are to be connected between rectifier and the smmothing capacitor.
And, the integrator that the voltage output that described current conversion unit, its characteristics be to comprise differential amplifier that described reactor both end voltage is amplified, amplify described differential amplifier is quadratured, the signal by described integrator integration carried out the filtering portion of low-pass filtering.
And described zero potential test section, its characteristics are at voltage to be the integration initialization initial point of zero the described integrator of position probing.
And, described control part, its characteristics are that the output signal according to filtering portion detects the input current of described inverter.
Description of drawings
Fig. 1 is the current detection circuit figure that traditional drive motors is used inverter.
Fig. 2 is that the inverter current that provides according to one embodiment of the invention detects loop diagram.
Embodiment
Below, the embodiment that present invention will be described in detail with reference to the accompanying.
Fig. 2 is that the inverter current that provides according to one embodiment of the invention detects loop diagram, with existing structure want with part represent with same-sign.
In Fig. 2, the loop of detecting input current of inverter comprises by differential amplifier 50, integrator 52, the current transformation unit that zero point, position test section 54 and filtering portion 56 constituted, wherein inverter loop comprises: the power supply commonly used 20 that interchange such as 220V 60Hz is provided is carried out full-wave rectification and the rectifier 22 exported, be positioned at the rear end of described rectifier 22 and improve the reactor (L) of power factor (PF), be connected to described rectifier 22 and the voltage of rectifier 22 output is carried out advection and converts the smmothing capacitor 24 of direct current to, the direct voltage of described smmothing capacitor 24 outputs is become 3 cross streams (U of impulse form by pulse width modulation (PWM) with any variable frequency, V, W) come the inverter 26 of drive motors, output offers the pwm signal pattern of described inverter 26 and comes the control part 32 of control inverter 26 by inverter driving portion 30.
Described inverter 26 is that 6 switch elements (IGBT) and 6 diodes (FRD) are connected into three phase full bridge circuit (Full Bridge) and direct voltage is converted to the common switching circuit that three-phase alternating voltage also is supplied to this three-phase alternating current motor 28.
Described control part 32 is ON/OFF (on/off) of 6 switch elements of control inverter 26, and produces the microprocessor with free voltage and optional frequency three-phase alternating current.Because this is to use the general fashion of PWM control, so omit its detailed description at this.Its output is with 120 ° of square waves connecting use constant amplitude PWM control and use 180 ° of the sine waves of not constant amplitude PWM control irrelevant.
Described differential amplifier 50 is connected to the reactor (L) that is used to improve power factor (PF) in power end one side of power supply 20 commonly used, and the both end voltage difference of reactor (L) carried out differential amplification, 52 pairs of voltage signals that amplified by differential amplifier 50 of integrator are quadratured.
Electric current, the voltage that described zero potential test section 54 detects power supply 20 commonly used is zero position (zero crossing: zero crossing) come the described integrator 52 of initialization, the unlimited integration that prevents integrator 52 causes saturated, carry out low-pass filtering (LPF) from 56 pairs of signals of filtering portion, and be input to the A/D converter of control part 32 by described integrator 52 ball integrations.
Thereby described control part 32 is according to the output signal of filtering portion 56, detects the power end electric current of the power supply commonly used 20 that is input to inverter 26 and controls the pwm signal pattern that offers inverter 26, thereby protected and control inverter 26 by maximum permissible power.
Below, the running and the action effect of the current sensing means of aforesaid inverter are described.
In Fig. 2, when going into to use power supply 22 always, the power supply commonly used 20 at alternating currents such as rectifier 22 rectifications supply 220V, 60Hz is undertaken level and smooth by the smmothing capacitor 24 that is connected in rectifier 22 and is converted to direct current exporting again.
The direct voltage of described smmothing capacitor 24 outputs is transformed to the three-phase alternating current with any variable frequency at inverter 26 by pulse-width modulation and is fed to motor 28, and drive motors 28 thus.
At this moment, control part 32 is for maximum permissible power protection and control inverter 26 and the input current of detection inverter 26.
For detecting the input current of described inverter 26, the present invention directly detects to improving the differential voltage at reactor (L) two ends that power factor (PF) is connected to power end one side of power supply 20 commonly used, and detects the power end electric current that is input to inverter 26 by several signal processing.
At first, reactor (L) both end voltage is as shown in the formula shown in 1:
Quadrature as if the voltage at reactor (L) two ends that utilize the described formula 1 of differential amplifier 50 methods and by the voltage signal of 52 pairs of amplifications of integrator, the electric current that flows through reactor can be put out following formula 2 in order by quadraturing from described formula 1 both sides:
Formula 2 as described, can put the equation into the electric current that passes through reactor (L) in order, because the D.C. resistance (R of reactor (L)
L) very little, the 2nd of formula 2 influences when detecting the whole input current of inverter not quite, therefore can put in order to be offset variable.
Thereby, after reactor (L) both end voltage quadratured and multiply each other with certain increment, deduct the power end electric current that deviant obtains being input to inverter 26.
The output of described integrator 52 has the form than the electric current of crossing reactor (L) in actual flow, obtains than in the value of current value after filtering portion 56 is low pass filtering.
In addition, described integrator 52 may be saturated by side-play amount in the 2nd of formula 2, causes and can't move, and therefore electric current, the voltage that detects power supply 20 commonly used by zero potential test section 54 is zero position, and at each cycle initialization integrator 52, thereby detect the electric current that deducts bias effect.
Thereby, the present invention does not make Current Transformer and directly detects reactor (L) both end voltage, can simplify the loop, and directly detect the electric current of power end one side of power supply 20 commonly used, therefore employed reactor (L) and integrator 52, filtering portion 56 etc. regularly need not setting in addition and can detect the input current of inverter 26.
In sum, according to inverter current detecotr provided by the present invention, need not special current transformer or redundant mesh, but be connected in the reactor both end voltage that power end improves the power factor (PF) of input current of inverter, thereby can correctly detect the power end electric current that is input to inverter by detection.
Claims (6)
1. inverter current detecotr, it is direct current that this inverter smoothly will be used power source conversion always according to the rectifier smmothing capacitor, is the motor that 3 cross streams power supplys of expected frequency come drive motors with the DC converting of conversion, it is characterized in that comprising:
Be connected to power end one side, with the reactor of the power factor that is used to improve described inverter;
Detect the both end voltage of described reactor and be converted into the current transformation unit of electric current; And
Detect the control part of the electric current that is input to described inverter according to the size of current of conversion.
2. inverter current detecotr as claimed in claim 1 is characterized in that described reactor is connected between rectifier and the smmothing capacitor.
3. inverter current detecotr as claimed in claim 1, it is characterized in that described current transformation unit comprises: the differential amplifier that described reactor both end voltage is amplified, the integrator that the output voltage that amplifies according to described differential amplifier is quadratured, the signal of quadraturing according to described integrator carried out the filtering portion of low-pass filtering.
4. inverter current detecotr as claimed in claim 3 is characterised in that described current transformation unit also comprises position test section at zero point, serves as zero position to be used to detecting electric current, the voltage of using power supply always, and is saturated to prevent described integrator from passing through integration.
5. inverter current detecotr as claimed in claim 4 is characterized in that, described zero potential test section is the integration initialization initial point of zero the described integrator of position probing at electric current, the voltage of power supply commonly used.
6. inverter current detecotr as claimed in claim 3 is characterized in that, described control part detects the current value that is input to described inverter according to the output signal of described filtering portion.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR1020060103102 | 2006-10-23 | ||
| KR1020060103102A KR20080036467A (en) | 2006-10-23 | 2006-10-23 | Apparatus for detecting input current of inverter |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN101170282A true CN101170282A (en) | 2008-04-30 |
Family
ID=39390777
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNA2007101022031A Pending CN101170282A (en) | 2006-10-23 | 2007-04-27 | Inverter current detecotr |
Country Status (3)
| Country | Link |
|---|---|
| JP (1) | JP2008109836A (en) |
| KR (1) | KR20080036467A (en) |
| CN (1) | CN101170282A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112462258A (en) * | 2020-11-06 | 2021-03-09 | 珠海格力电器股份有限公司 | Motor terminal voltage detection method, device and circuit and air conditioning system |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2011205729A (en) * | 2010-03-24 | 2011-10-13 | Daikin Industries Ltd | Power conversion equipment |
| CN102981042B (en) * | 2012-12-07 | 2014-12-10 | 深圳市安邦信电子有限公司 | Three-phase current detection circuit for frequency converter |
| JP6435841B2 (en) * | 2014-12-17 | 2018-12-12 | アイシン精機株式会社 | Inverter device |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0429879U (en) * | 1990-05-18 | 1992-03-10 | ||
| JPH09266694A (en) * | 1996-03-27 | 1997-10-07 | Fujitsu General Ltd | Controller for air conditioner |
| JP3454186B2 (en) * | 1999-05-14 | 2003-10-06 | 株式会社日立製作所 | Power converter |
| US7235962B2 (en) * | 2003-11-17 | 2007-06-26 | Babak Mazda | Inductor-based current sensing |
-
2006
- 2006-10-23 KR KR1020060103102A patent/KR20080036467A/en not_active Application Discontinuation
-
2007
- 2007-04-24 JP JP2007114559A patent/JP2008109836A/en active Pending
- 2007-04-27 CN CNA2007101022031A patent/CN101170282A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112462258A (en) * | 2020-11-06 | 2021-03-09 | 珠海格力电器股份有限公司 | Motor terminal voltage detection method, device and circuit and air conditioning system |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2008109836A (en) | 2008-05-08 |
| KR20080036467A (en) | 2008-04-28 |
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| PB01 | Publication | ||
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| SE01 | Entry into force of request for substantive examination | ||
| AD01 | Patent right deemed abandoned |
Effective date of abandoning: 20080430 |
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| C20 | Patent right or utility model deemed to be abandoned or is abandoned |