WO2005112219A1

WO2005112219A1 - Active filter

Info

Publication number: WO2005112219A1
Application number: PCT/JP2004/006816
Authority: WO
Inventors: Masaji Haneda
Original assignee: Ntt Data Ex Techno Corporation
Priority date: 2004-05-13
Filing date: 2004-05-13
Publication date: 2005-11-24

Abstract

An active filter comprises a bi-directional inverter (INV1) for delivering/leading in a compensation current used for compensating a harmonic current generated from a load connected to a commercial power supply, a capacitor (C1) connected to the DC side of the bi-directional inverter (INV1) and serving as a compensation current supply, a current transformer (CT1) for detecting a current component flowing into the commercial power supply, and a voltage transformer (PT) for detecting the voltage component of the commercial power supply. The bi-directional inverter (INV1) is controlled in accordance with a synthesis signal of a commercial current detection signal detected by the current transformer (CT) and a commercial voltage detection signal detected by the voltage transformer (PT).

Description

Active filter device

Technical field

The present invention relates to an active filter device that is inserted between a commercial power supply and a load and performs current compensation, power factor improvement, and the like.

The present invention also relates to an active filter device having excellent response speed.

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Background art

In recent home appliances such as personal computers, refrigerators, air conditioners, and lighting fixtures, an inverter power supply is built inside. Equipment incorporating this inverter power supply has features such as quiet power consumption and power saving if switching between 5 OH z and 6 OH _Z is not necessary, so its use will be further promoted in the future. It is expected. On the other hand, devices incorporating this inverter power supply are also viewed as having problems such as the deterioration of the power factor of the load due to the harmonic current flowing through the load and the reduction of power use efficiency. As a conventional technique for solving these problems, for example, there is an active filter device described in Patent Document 1 below. The active filter device described in this document includes a compensation capability determiner, a power factor improvement compensation current control circuit, a reactive current compensation current control circuit, a compensation current control circuit, and the like. The excess compensation capability of the compensation current that can be generated by the inverter is determined based on the voltage of the DC power supply connected to the power supply, and the power factor improvement compensation current control circuit matches the excess compensation capability determined by the compensation capability determiner. The reactive current compensation current control circuit calculates the reactive current compensation current corresponding to the surplus compensation capability.The compensation current control circuit calculates the harmonic compensation current and the power factor. By calculating a compensation current based on the improvement compensation current or harmonic compensation current and the reactive current compensation current and issuing a control command to the inverter, the harmonic Patent Document 1

SUMMARY OF THE INVENTION Incidentally, in the above-described active filter device of the related art, a circuit for detecting a fundamental wave current flowing in a power supply system and a harmonic are disclosed. Circuit for detecting current, circuit for detecting operating power factor from phase signal of power supply voltage and fundamental wave current, circuit for generating compensation current, and other various types such as phase inversion circuit, phase shift circuit, adder, multiplier, etc. Since various circuits are used, the configuration of the device is complicated, and the device has a drawback that the device is expensive. In addition, since the waveform analysis of the signal waveform is indispensable to generate the compensation current, there is a problem that the response speed is slow.

In view of such a situation, an object of the present invention is to provide an active filter device which has a simple device configuration, and does not particularly require any means such as waveform analysis and has an excellent response speed. Disclosure of the invention

In the active filter device according to the present invention, an inverter for transmitting and drawing a compensation current for compensating a harmonic current generated from a load connected to a commercial power supply, and an inverter connected to a DC side of the inverter. An active filter device comprising: a compensation current supply means serving as a supply source of the compensation current; and a control means for controlling the inverter, wherein the control means detects a current component flowing to the commercial power supply A commercial current detection means, and a commercial voltage detection means for detecting a voltage component of the commercial power supply, a commercial current detection signal detected by the commercial current detection means, and a commercial voltage detection signal detected by the commercial voltage detection means. The inverter is controlled based on the combined signal of the inverter.

According to the invention, a commercial current detecting means for detecting a current component flowing to a commercial power supply, The control means including commercial voltage detection means for detecting the voltage component of the commercial power supply is based on a composite signal of the commercial current detection signal detected by the commercial current detection means and the commercial voltage detection signal detected by the commercial voltage detection means. To control the inverter.

In the active filter device according to the next invention, the control means charges the compensation current supply means based on a change in terminal voltage of the compensation current supply means connected to the DC side of the inverter. ΖDischarge is controlled. According to this invention, the control means controls charging / discharging of the compensation current supply means based on a change in the terminal voltage of the compensation current supply means connected to the DC side of the inverter. In the active filter device according to the next invention, the control means includes: a first amplifier that amplifies the commercial current detection signal; and a second amplifier that amplifies the commercial voltage detection signal. The control of the charge amount of the compensation current supply means is performed by gain control of the second amplifier based on a terminal voltage of the compensation current supply means.

According to the present invention, the control means including the first amplifier for amplifying the commercial current detection signal and the second amplification ^ for amplifying the commercial voltage detection signal is based on the terminal voltage of the compensation current supply means. By controlling the gain of the second amplifier, the charge amount of the compensation current supply means is controlled.

In the active filter device according to the next invention, the compensation current supply means is constituted by a capacitor.

According to the present invention, an active filter device can be easily configured using a capacitor.

In the active filter device according to the next invention, the control means includes: a first amplifier that amplifies the commercial current detection signal; and a second amplifier that amplifies the commercial voltage detection signal. It is characterized in that the control of sending out of the compensation current performed by the inverter is performed by gain control of the first amplifier based on the compensation current.

According to the present invention, the first amplifier for amplifying the commercial current detection signal and the commercial voltage detection The control means including the second amplifier for amplifying the output signal controls the Z-pull-in of the compensation current, which is performed by the inverter, by controlling the gain of the first amplifier based on the compensation current. In the active filter device according to the present invention, the control means includes: a first amplifier that amplifies the commercial current detection signal; a second amplifier that amplifies the commercial voltage detection signal; and a current of the compensation current. And compensating current detecting means for detecting a component, wherein the control of the amount of charge of the compensating current supplying means is performed by controlling the gain of the second amplifier based on the terminal voltage of the compensating current supplying means. The control of the output of the compensation current and the Z-pull-in performed by the inverter is performed by gain control of the first amplifier based on the current component detected by the compensation current detection means. According to the present invention, the control means including the first amplifier for amplifying the commercial current detection signal and the second amplifier for amplifying the commercial voltage detection signal comprises: By controlling the gain of the second amplifier, the charge amount of the current supply means is controlled. Further, the control means controls transmission and pull-in of the compensation current performed by the inverter by performing gain control of the first amplifier based on the compensation current.

In the active filter device according to the next invention, there is provided an inverter for transmitting / drawing in a compensation current for compensating for a phase lag advance current generated from a load connected to a commercial power supply, and a DC side of the inverter. In an active filter device comprising: a compensating current supply unit connected as a supply source of the compensation current; and a control unit for controlling the inverter, the control unit converts a current component flowing to the commercial power supply into A commercial current detection means for detecting the voltage component of the commercial power supply, a commercial current detection signal detected by the commercial current detection means, and a commercial voltage detection signal detected by the commercial voltage detection means. The inverter is controlled based on a combined signal with the signal.

According to this invention, the control means including the commercial current detecting means for detecting the current component flowing to the commercial power supply and the commercial voltage detecting means for detecting the voltage component of the commercial power supply, Current detection signal and commercial voltage detected by commercial voltage detection means The inverter is controlled based on the combined signal with the detection signal.

In the active filter device according to the next invention, the control means is configured to charge the compensation current supply means based on a change in terminal voltage of the compensation current supply means connected to the DC side of the inverter. Controlling z discharge.

According to this invention, the control means controls the charge Z discharge of the compensation current supply means based on the change in the terminal voltage of the compensation current supply means connected to the DC side of the inverter. In the active filter device according to the next invention, the control means includes: a first amplifier that amplifies the commercial current detection signal; a second amplifier that amplifies the commercial voltage detection signal; A compensating current detecting means for detecting a current component of the current, wherein a control of a charge amount of the compensating current supplying means is based on a terminal voltage of the compensating current supplying means. The compensation is performed by the inverter, and the control of the sending and drawing of the compensation current performed by the inverter is performed by a gain control of the first amplifier based on a current component detected by the compensation current detection unit. . According to the present invention, the control means including the first amplifier for amplifying the commercial current detection signal and the second amplifier for amplifying the commercial voltage detection signal is based on the terminal voltage of the compensation current supply means. In addition, by controlling the gain of the second amplifier, the charge amount of the compensation current supply means is controlled. Further, the control means controls the sending / drawing-in of the compensation current performed by the inverter by the IJ gain control of the first amplifier based on the compensation current. Brief Description of Drawings

FIG. 1 is a diagram showing a circuit configuration according to an embodiment of the present invention. FIG. 2A is a diagram showing waveforms of a voltage signal or a current signal of a main part of the active filter device, and FIG. The figure shows the waveform of the input signal to the bidirectional inverter.The figure 3 shows that the commercial current is improved by the compensation current of the bidirectional inverter INV 1 when a load current containing harmonics flows through the load. Fig. 4 shows how the phase lag is improved by the compensation current of the bidirectional inverter INV1 when a phase lag current with a phase lag flows through the load. FIG. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, preferred embodiments of an active filter device according to the present invention will be described in detail with reference to the accompanying drawings. The present invention is not limited by the embodiment.

Embodiment 1.

FIG. 1 is a diagram showing a circuit configuration according to an embodiment of the present invention. Referring to FIG. 1, an active filter device 10 having an input terminal and an output terminal includes a voltage transformer PT, current transformers CT1 and CT2, variable gain voltage control amplifiers AGCl and AGC2, an inverting circuit PR1 and It has an adder circuit SUM1, a bidirectional inverter I NV1, a diode D1, and capacitors C1 and C2. A commercial power supply is connected to the input terminal of the active filter device 10, and a load is connected to the output terminal.

Next, a circuit configuration of the active filter device 10 according to the embodiment will be described. In FIG. 1, the voltage transformer PT has a primary winding and a secondary winding. The primary winding of the voltage transformer PT is connected to a power supply line in the active filter device 10. The secondary winding is connected to the inverting circuit PR1. The current transformer CT1 is connected to one end of the power supply line in the active filter device 10 so as to detect a current flowing through the power supply line without being inserted into the power supply line. You. The summing circuit SUM 1 has its input side connected to the variable gain voltage control amplifier AGC 1 connected to the current transformer CT 1 and the variable gain voltage control amplifier AGC 2 connected to the inverting circuit PR 1, and has both output sides. Inverter I Connect to NV1.

The bidirectional inverter INV 1 has a pair of DC terminals DT 1 and DT 2 and a pair of AC terminals AT 1 and AT 2. The AC side terminal AT1 of the bidirectional inverter INV1 is connected to one power supply line, and the AC side terminal AT2 is connected to the other power supply line. The DC terminal DT 1 of the bidirectional inverter INV 1 The DC terminal DT2 is connected to the other end of the capacitor C1 (the ground terminal which is also grounded to the circuit ground). One end of the capacitor C1 connected to the DC terminal DT1 of the bidirectional inverter INV1 is also connected to the variable gain voltage control amplifier AGC2. On the line connecting the DC side terminal DT1 of the bidirectional inverter I NV1 and one power supply line, a current transformer CT2 connected to the diode D1 node; Connected by The force sword of the diode D1 is connected to the variable gain voltage control amplifier AGC1 and also to one end of the capacitor C2. The other end of the capacitor C2 is set to the circuit ground similarly to the capacitor C1.

Next, the operation of the active filter device 10 shown in FIG. 1 will be described. I1, ί2, and I3 shown in the figure represent a commercial current flowing on the commercial power supply side, an inverter current output from the bidirectional inverter I NV1, and a load current flowing on the load side, respectively. By the way, as is clear from the figure, only the current transformer C T1 exists on the power supply line for supplying the commercial power between the commercial power and the load. The current transformer CT1 detects the current flowing through the load without being inserted into the power supply line, and does not affect the operation between the commercial power supply and the load. Therefore, when the active filter device 10 does not act on the commercial power supply or the load, that is, when the inverter current I2 does not flow, the commercial current becomes the load current as it is.

In FIG. 1, a voltage transformer Ρ detects a power supply voltage Vin supplied from a commercial power supply, and a current transformer CT 1 detects a commercial current 11 flowing in a power supply line. The voltage signal detected by the voltage transformer PT is inverted by the inverting circuit PR1, and is input to the variable gain voltage control amplifier AGC2. On the other hand, the current signal detected by the current transformer CT 1 is directly input to the variable gain voltage control amplifier AGC 1. These signals are amplified by the variable gain voltage control amplifiers AGC1 and AGC2, added by the addition circuit SUM1, and output from the addition circuit SUM1 as an input signal to the bidirectional inverter I NV1. . The capacitor C1 connected to the DC terminals DT1 and DT2 of the bidirectional inverter INV1 is for holding a predetermined DC voltage. Further, the capacitor C 1 is a supply source of the inverter current I 2 that the bidirectional inverter INV 1 flows through the power supply line. In the capacitor C1, a charging operation and a discharging operation are performed alternately according to the direction in which the inverter current I2 flows. That is, when the inverter current I2 is in the direction shown in Fig. 1 (when the inverter current I2 operates so as to supply the inverter current I2 to the commercial current I1), the capacitor C1 performs a discharging operation. When the inverter current I2 is opposite to the direction shown in Fig. 1 (when the inverter current I2 is drawn from the commercial current I1), the capacitor C1 performs a charging operation.

Bidirectional inverter 加算 Adder circuit S UM 1 output at the AC side terminals AT 1 and AT 2 of NV 1 ^ A predetermined voltage is generated based on the output signal that is output, and the predetermined inverter current I from AC side terminal AT 1 2 flows and is supplied to the power line. As is evident from FIG. 1, there is a relationship of 1 3 = 1 1 + 1 2 between the commercial current I 1, the inverter current I 2 and the load current I 3. This means that the commercial power supply and the two-way inverter I N V 1 distribute the current supplied to the load. At this point, various currents flow through the load depending on the load itself. For example, a load superimposed with harmonics and a phase-lagging / leading current flows through the load.The inverter current I2 takes charge of these harmonic currents and the phase-lagging / leading current, and the The waveform of the current I1 can be improved. By this effect, the power factor on the commercial power supply side can be improved and the usage efficiency can be improved. The operation of supplying the inverter current I2 will be described later.

The current transformer CT2 detects the current of the inverter current I2 supplied by the bidirectional inverter INV1. This detection current is charged to the capacitor C2 through the diode D1. The voltage charged in the capacitor C2 is used as a control signal for the variable gain voltage control amplifier AGC1. This control signal is used as a current drooping control signal for the inverter current I 2, that is, when the inverter current I 2 exceeds the allowable capacity that the bidirectional inverter INV 1 can supply, the inverter current I 2 is suddenly cut off. (Not supplied to the power line). Therefore, when the voltage charged in the capacitor C2 exceeds a predetermined voltage value, the gain of the variable gain voltage control amplifier AGC1 is reduced, and the signal supplied to the addition circuit SUM1 is reduced. The voltage charged in the capacitor C2 is determined at predetermined intervals based on a capacitance value of the capacitor C2, a time constant determined by a resistor (not shown), an input impedance of the variable gain voltage control amplifier AGC1, and the like. (Eg, every commercial power cycle). .

On the other hand, the voltage charged in the capacitor C1 is used as a control signal for the variable gain voltage control amplifier AGC2. This control signal is supplied to the variable gain voltage control amplifier AGC2 for controlling the amount of charge charged in the capacitor C1. As will be clarified in the description of the operation of the inverter current I2 described later, when the output from the adding circuit SUM1 is negative, the capacitor C1 is charged, and conversely, when the output from the adding circuit SUM1 is positive. In this case, a discharge current flows from the capacitor C1. Therefore, when the voltage of the capacitor C1 is large, the gain of the variable gain voltage control amplifier AGC '2 is controlled to decrease. Conversely, when the voltage of the capacitor C1 is small, the variable gain voltage control amplifier AGC2 is controlled. Is controlled so as to increase the gain. Also, while the gain of the variable gain voltage control pump AGC1 is rapidly controlled based on the voltage of the capacitor C2, the gain of the variable gain voltage control pump AGC2 is changed according to the terminal voltage of the capacitor C1. It is controlled continuously.

FIG. 2 is a diagram showing a waveform of a voltage signal or a current signal of a main part of the active filter device 10, and FIG. 2B is a diagram showing a waveform of an input signal to the bidirectional inverter INV1. . In FIG. 2A, a portion shown by a thin solid line, that is, a signal K1 is a voltage signal of a commercial power supply detected by the voltage transformer PT. The portion indicated by the thick line and the solid line, that is, the signal K2 is a current signal detected by the current transformer CT1. The signal K3 in the signal K2, which is the current signal, is due to the harmonic current generated in the load. On the other hand, the portion shown by the broken line, that is, the signal 4 is an inverted waveform inverted by the inverting circuit PR1. Signal 2 is input to the variable gain voltage control amplifier AGC 1 and signal 4 is input to the variable gain voltage control amplifier AGC 2 so that the variable gain voltage control amplifier AGC 1 and the variable gain voltage control amplifier AGC 2 each have a predetermined gain. When set, the signal shown in FIG. 2B is output from the adder circuit SUM1. At this time, due to the normal function of the bidirectional inverter INV1, when this signal is positive, the inverter current I2 proportional to the current shown in the figure is supplied from the bidirectional inverter INV1 toward the power supply line. You. Conversely, when this signal is negative, the inverter current .I2 proportional to the current shown in the figure is drawn from the power supply line to the bidirectional inverter INV1. More specifically, referring to FIG. 2B, the current is extracted in the shaded L1 portion, and the current is supplied in the shaded L2 portion. In conjunction with these operations, the capacitor C1 performs charging or discharging operations, respectively. That is, in the portion of L1, the capacitor C1 is charged by the inverter current I2 drawn from the power supply line, and in the portion of L2, the inverter current I2 toward the power supply line is discharged by the current discharged from the capacitor C2. Is supplied.

FIG. 3 is an explanatory diagram showing how the commercial current is improved by the compensation current of the bidirectional inverter I NV1 when a load current including harmonics flows through the load. In the figure, (a) shows the waveform of the power supply voltage (V in), (b) shows the waveform of the inverted signal of the power supply voltage of (a), and (c) shows the waveform of the load current including harmonics. (D) shows the waveform of the compensation current extracted from the bidirectional inverter INV1, and (e) shows the waveform of the final commercial current.

The voltage transformer PT detects the signal shown in FIG. 3 (a), and the inverting circuit PR1 generates the signal shown in FIG. 3 (b). On the other hand, the current transformer CT 1 detects the signal shown in the figure (). This detection signal is obtained by detecting the commercial current I 1 at the moment when the load current I 3 including the harmonic flows on the commercial power supply side. The signals shown in FIGS. 3B and 3C are respectively input to the variable gain voltage control amplifier AGC 2 and the variable gain voltage control amplifier AGC 1 and the variable gain voltage control amplifier AG C 1 and the gain of the variable gain voltage control amplifier AGC 2 are properly controlled. Then, according to the above-described operation, the compensation current (inverter current 12) shown in FIG. 11D is supplied from the bidirectional inverter INV1 to the power supply line. As described above, when the load current I3 including the harmonic current flows to the load and the harmonic current flows to the commercial power supply, a change in the commercial current I1 on the commercial power supply is detected, and this change component is detected. Compensated by the inverter current I2. As a result, as the commercial current I1, a current having a sinusoidal waveform as shown in FIG.

FIG. 4 is an explanatory diagram showing how the phase lag is improved by the compensation current of the bidirectional inverter I NV1 when a phase lag current with a phase lag flows through the load. In the figure, (a) shows the waveform of the power supply voltage (V in), (b) shows the waveform of the inverted signal of the power supply voltage of (a), (c) shows the waveform of the delay current, and (d) () Shows the waveform of the compensation current extracted from the bidirectional inverter INV1, and (e) shows the waveform of the final commercial current.

Also in this case, the same operation as when a harmonic current flows on the commercial power supply side is performed, and the waveform on the commercial power supply side is improved by the compensation current of the bidirectional inverter INV1. This waveform improvement is performed by the compensation current of the bidirectional inverter 1 NV1, so that the current flowing to the load may be any waveform current. For example, the waveform of the commercial current can be improved even if the current flowing through the load is a leading current, or if the harmonic current and the lagging current or the leading current occur simultaneously.

In this way, when the harmonic current or the lagging advance current generated in the load flows to the commercial power supply, these currents flowing to the commercial power supply are detected, and these currents are compensated by the bidirectional inverter INV 1. As a result, the harmonic component of the current signal flowing to the commercial power supply can be removed, and the lag-lead current can be compensated, and the waveform of the commercial current can be improved. Also, since the capacitor C1 operates so as to alternately charge or discharge, a circuit can be realized without using a large-capacity capacitor. Also, based on the voltages of the capacitors C1 and C2, the variable gain voltage control amplifier AGC2 and the variable gain voltage control Since the gain of the amplifier AGC 1 is controlled, an appropriate inverter current I 2 according to the capability of the bidirectional inverter INV 1 can be supplied to the power supply line. As described above, according to the present embodiment, an inverter that sends out a compensation current for compensating for a harmonic current generated from a load connected to a commercial power supply, and a Z-pull-in inverter, and is connected to the DC side of the inverter And a control means provided with a commercial current detecting means and a commercial voltage detecting means for controlling the inverter. The commercial current detecting means detects the commercial current detected by the commercial current detecting means. Since the inverter is controlled based on the combined signal of the signal and the commercial voltage detection signal detected by the commercial voltage detection means, no matter what kind of waveform current flows to the commercial power supply due to the current flowing to the load This also has the effect that the waveform of the commercial current can be improved.

Further, according to this embodiment, the control means controls the charge / discharge of the compensation current supply means based on a change in the terminal voltage of the compensation current supply means connected to the DC side of the inverter. This has the effect that control of the compensation current according to the supply capability of the compensation current supply means can be realized.

Further, according to this embodiment, the control means including the first amplifier for amplifying the commercial current detection signal and the second amplifier for amplifying the commercial voltage detection signal is based on the terminal voltage of the current supply means. In addition to controlling the amount of charge of the current supply means by controlling the gain of the second amplifier, and transmitting the compensation current performed by the inverter by controlling the gain of the first amplifier based on the compensation current. Since the pull-in control is performed, there is no need to perform waveform analysis or the like, and it is possible to achieve an excellent response speed and an effect that the device can be configured simply and inexpensively.

The control stage here is the voltage transformer PT, current transformer CT1, CΤ2, variable gain amplifier AGC]., AGC2, inverting circuit PR1, adding circuit SUM1, capacitor Cl, Implemented by diode D1.

In addition, the commercial current detection means here corresponds to the current transformer CT1. Similarly, the commercial voltage detection means corresponds to the voltage transformer PT, and the compensation current supply means Corresponds to the capacitor C1, the first amplifier corresponds to the variable gain amplifier AGC2, and the second amplifier corresponds to the variable gain amplifier AGC1.

Industrial applicability

INDUSTRIAL APPLICABILITY As described above, the present invention is useful as an active filter device that is inserted between a commercial power supply and a load to perform current compensation, power factor improvement, and the like. This function is suitable for simply configuring functions to perform such functions as to ensure excellent response speed performance.

Claims

The scope of the claims

1. Compensation current for compensating for the harmonic current generated from the load connected to the commercial power supply. Inverter for drawing in. Compensation current connected to the DC side of this inverter and serving as the supply source of the compensation current. An active filter device comprising: a supply unit; and a control unit for controlling the inverter.

The control means,

Commercial current detecting means for detecting a current component flowing to the commercial power supply,

Commercial voltage detecting means for detecting a voltage component of the commercial power supply;

With

An active filter device, wherein the inverter is controlled based on a composite signal of a commercial current detection signal detected by the commercial current detection means and a commercial voltage detection signal detected by the commercial voltage detection means. 2. The control means controls charging / discharging of the compensation current supply means based on a change in terminal voltage of the compensation current supply means connected to the DC side of the inverter. 2. The active filter device according to claim 1, wherein:

3. The control means includes:

A first amplifier for amplifying the commercial current detection signal;

A second amplifier for amplifying the commercial voltage detection signal;

With

3. The method according to claim 2, wherein the control of the charge amount of the compensation current supply means is performed by gain control of the second amplifier based on a terminal voltage of the compensation current supply means. Active filter device.

4. The compensation current supply means is composed of a capacitor. An apparatus as described in paragraph 22 below. .

55 .. The above-mentioned control means comprises:

An eleventh amplification amplifier for increasing the amplification of the commercial and commercial current detection detection signal;

A twenty-second multiplication amplifier for increasing the amplification of the commercial and commercial voltage detection detection signal;

Equipped with,

The control of the sending and receiving of the supplementary compensation current flow of the supplementary compensation current flow is performed before the compensation battery current flow is performed by the inverter. The operation performed by the gain control of the eleventh amplification amplifier device according to the eleventh embodiment described above is a characteristic feature. Scope of the request

6. The control means includes:

A first amplifier for amplifying the commercial current detection signal;

A second amplifier for amplifying the commercial voltage detection signal;

Compensation current detection means for detecting a current component of the compensation current;

With

The control of the charge amount of the compensation current supply means is performed by gain control of the second amplifier based on the terminal voltage of the compensation current supply means,

3. The method according to claim 2, wherein the control of sending and drawing of the compensation current performed by the inverter is performed by a gain control of the first amplifier based on a current component detected by the compensation current detection unit. An active filter device according to item 1.

7. The phase delay Z generated from the load connected to the commercial power supply, the compensation current for compensating the Z-lead current, the inverter that draws in, and the inverter that is connected to the DC side of the inverter and becomes the supply source of the compensation current An active filter device comprising: a compensation current supply unit; and a control unit for controlling the inverter.

The control means,

Commercial current detecting means for detecting a current component flowing to the commercial power supply, Commercial voltage detecting means for detecting a voltage component of the commercial power supply,

Controlling the inverter based on a composite signal of the commercial current detection signal detected by the commercial current detection means and the commercial voltage detection signal detected by the commercial voltage detection means.

8. The control means controls charging / discharging of the compensation current supply means based on a change in terminal voltage of the compensation current supply means connected to the DC side of the inverter. Item 7. The active filter device according to item 7, wherein

9. The control means includes:

A first amplifier for amplifying the commercial current detection signal;

A second amplifier for amplifying the commercial voltage detection signal;

With

The charge amount of the compensation current supply means is controlled by gain control of the second amplifier based on the terminal voltage of the compensation current supply means,

The control of sending / drawing-in of the compensation current performed by the inverter is performed by gain control of the first amplifier based on a current component detected by the compensation current detection means. An active filter device according to the item.