JP3360838B2 - Control device for power converter for reactive power and harmonic compensation - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention controls a reactive power and harmonics compensating power converter having a limiter for limiting the pq axis by using the pq calculation for the calculation of the output current command value. Regarding the device.

[0002]

2. Description of the Related Art An example of a control device for a reactive power and harmonics compensating power converter having a conventional limiter will be described with reference to FIGS.

In FIG. 5, reference numeral 1A is a current command calculation circuit for giving a current command ic ^* to the inverter 2 as will be described below. This is a pq calculation circuit 3A and power calculation circuits 4A, p.
It is composed of a limiter 5A on the q-axis, an inverse pq calculation circuit 6A, and an absolute value limiter 7A.

FIG. 6 is an example showing the structure of the limiter 5A on the pq axes of FIG. 5, 11 is a vector operation circuit, 12 is a peak detection circuit, 16 is an inverse function operation circuit, 14 is an absolute value limiter, and 17 is Each is a multiplication circuit.

In FIG. 5, the electric power calculated based on the system voltage and the current iL detected by the current transformer is divided into an instantaneous actual power p and an instantaneous imaginary power q by the pq arithmetic circuit 3A. The divided instantaneous power is discriminated by the power calculation circuit 4A into the harmonic power components Ph and Qh and the reactive power component Qo. Each discriminated component Ph, Qh, Qo is p
The limiter 5A on the q-axis limits the sizes of the components Ph, Qh, and Qo. Power component Ph with limited magnitude
1, Qh1 and Qo are converted into the output current command value ic ^* by the inverse pq calculation circuit 6. The absolute value limiter 7A inputs the output current command ic1 ^* to the inverter 2 and outputs the current ic.

The operation of the limiter 5A on the pq axes will be described with reference to FIG. The magnitudes of the harmonic power components Ph and Qh are calculated by the vector calculation circuit 11, and the peak values are held by the peak detection circuit 12. Reference numeral 16 denotes an inverse function calculation circuit, which calculates gains k1 and k2 that keep the magnitude hmax constant when the magnitude of the harmonic power component exceeds the set value hmax. The multiplication circuits 17 multiply the gains k1 and k2 by the harmonic power components Ph and Qh, respectively, so that the magnitude of the harmonic power command value is kept constant.
The magnitude of the reactive power component Qo1 is limited by the absolute value limiter 14 so as to be equal to or less than the set value Qomax.
The upper limits of the harmonic power component and the reactive power component are set according to the device rating or the load condition.

[0007]

The control device of such a power converter for reactive power and harmonic compensation has a composite function in which functions such as harmonic suppression and reactive power compensation are combined. Since the limiter limit value is set, the capacity of the power converter is divided into power components in advance, and if one of the outputs exceeds the limit value or one of them is below the limit value, the power The capacity of the converter is not efficiently divided, and the capacity of the power converter is not utilized to the maximum.

An object of the present invention is to provide a control device for a reactive power and harmonics compensating power converter which can maximize the capacity of the device.

[0009]

In order to achieve the above object, the invention corresponding to claim 1 is a controller for a reactive power and harmonic compensating power converter for compensating reactive power and harmonics of a power system. In addition, the voltage and the detection current of the power system are taken in, and the power calculated based on this is
A pq arithmetic circuit for dividing an instantaneous real power p and an instantaneous imaginary power q,
A power calculation circuit for discriminating the power divided by the pq calculation circuit into a harmonic power component and a reactive power component, and a harmonic power component discriminated by the power calculation circuit are input to calculate an effective value of the harmonic power. And a peak detection circuit that detects and holds the peak value of the effective value of the harmonic power calculated by the vector calculation circuit, and the reactive power component discriminated by the power calculation circuit is input, and the reactive power is input. When the component exceeds a certain value, a harmonic compensation capacitance calculation device that outputs a gain in inverse proportion to the reactive power component, and the peak value of the effective value of the harmonic power held by the peak detection circuit are input. , A constant gain is output when the harmonic compensation capacity is less than or equal to a limit value that is varied by the gain from the arithmetic unit,
A harmonic compensation gain calculation device that outputs a gain that is inversely proportional to a quadratic curve with respect to the peak value of the effective value of the harmonic power when the limit value is exceeded, and a reactive power component discriminated by the power calculation circuit. Is input, a gain that is directly proportional to the reactive power component is output when the absolute value of the limit value that is changed by the gain from the harmonic compensation capacity calculation device is less than or equal to the absolute value, and a constant value is output when the absolute value of the limit value is exceeded. First to output the gain of
Of the absolute value limiter, the harmonic power command value is obtained from the product of the harmonic power component discriminated by the power calculation circuit and the gain of the harmonic compensation gain calculation device, and the reactive power component and the first absolute value are calculated. A multiplication circuit that obtains a reactive power command value from the product of the output of the value limiter and a gain, and an inverse pq that inputs the harmonic power command value and the reactive power command value that are the outputs of the multiplication circuit to obtain an output current command value. An arithmetic circuit, and a second absolute value limiter that inputs the output current command value of the inverse pq arithmetic circuit and outputs the output current command value limited to the rating of the power conversion device to the power conversion device. It is a control device of a power converter for reactive power and harmonic compensation.

In order to achieve the above object, the invention according to claim 2 is a controller for a reactive power and harmonic compensating power converter for performing reactive power and harmonic compensation of a power system. A pq arithmetic circuit that takes in the voltage and detected current of the system and divides the electric power calculated based on this into an instantaneous real power p and an instantaneous imaginary power q, and the power divided by the pq arithmetic circuit as a harmonic power component. A power calculation circuit for discriminating into a reactive power component, a vector calculation circuit for calculating the effective value of the harmonic power by inputting the harmonic power component discriminated by the power calculation circuit, and a harmonic calculated by the vector calculation circuit. When a peak detection circuit that detects and holds the peak value of the effective value of the wave power and the peak value of the effective value of the harmonic power that is held by the peak detection circuit are input, and the peak value exceeds a certain value The reactive power compensation capacity calculation device that outputs a gain inversely proportional to the peak value, and the peak value of the effective value of the harmonic power held by the peak detection circuit are input, and the reactive power compensation capacity calculation device is input. Outputs a constant gain when it is less than or equal to the limit value that can be changed by the gain of
A harmonic compensation gain calculation device that outputs a gain that is inversely proportional to a quadratic curve with respect to the peak value of the effective value of the harmonic power when the limit value is exceeded, and a reactive power component discriminated by the power calculation circuit. Is input, a gain that is directly proportional to the reactive power component is output when the absolute value of the limit value that is changed by the gain from the reactive power compensation capacity calculation device is less than or equal to the absolute value, and a constant value is output when the absolute value of the limit value is exceeded. A first absolute value limiter for outputting the gain of the harmonic power command value, a harmonic power component discriminated by the power calculation circuit and a product of the gain of the harmonic compensation gain calculation device to obtain a harmonic power command value, and the reactive power. A multiplication circuit for obtaining the reactive power command value from the product of the component and the gain that is the output of the first absolute value limiter, and the harmonic power command value and the reactive power command value that are the outputs of the multiplication circuit are input and output. An inverse pq arithmetic circuit that obtains a current instruction value, and a second absolute that inputs the output current instruction value of the inverse pq arithmetic circuit and outputs the output current instruction value limited to the rating of the power converter to the power converter. A control device for a reactive power and harmonics compensating power converter comprising a value limiter.

In order to achieve the above object, an invention according to claim 3 is a control device for a reactive power and harmonic compensating power converter for compensating reactive power and harmonics of a power system. A pq arithmetic circuit that takes in the voltage and detected current of the system and divides the electric power calculated based on this into an instantaneous real power p and an instantaneous imaginary power q, and the power divided by the pq arithmetic circuit as a harmonic power component. A power calculation circuit for discriminating into a reactive power component, a vector calculation circuit for calculating the effective value of the harmonic power by inputting the harmonic power component discriminated by the power calculation circuit, and a harmonic calculated by the vector calculation circuit. The peak detection circuit that detects and holds the peak value of the effective value of the wave power and the reactive power component discriminated by the power calculation circuit are input, and when the reactive power component exceeds a certain value, the reactive power generation is performed. And a harmonic compensation capacity calculation device that outputs a gain in inverse proportion to the peak value of the effective value of the harmonic power held in the peak detection circuit, and when the peak value exceeds a certain value, A reactive power compensation capacity calculation device that outputs a gain in inverse proportion to a peak value, and a peak value of the effective value of the harmonic power held by the peak detection circuit are input, and the harmonic compensation capacity calculation device or the above A constant gain is output when the value is less than or equal to a limit value that is varied by the gain from the reactive power compensation capacity calculation device, and when the limit value is exceeded, 2 is applied to the peak value of the effective value of the harmonic power.
A harmonic compensation gain calculation device that outputs a gain inversely proportional to the following curve, and a reactive power component discriminated by the power calculation circuit are input, and the harmonic compensation capacity calculation device or the reactive power compensation capacity calculation device A first absolute value limiter that outputs a gain that is directly proportional to the reactive power component when the absolute value of the limit value that is changed by the gain is less than or equal to the absolute value, and outputs a constant gain when the absolute value of the limit value is exceeded. The harmonic power command value is obtained from the product of the harmonic power component discriminated by the power calculation circuit and the gain of the harmonic compensation gain calculation device, and is the output of the reactive power component and the first absolute value limiter. A multiplication circuit for obtaining the reactive power command value from the product of the gain and an inverse pq function for obtaining the output current command value by inputting the harmonic power command value and the reactive power command value which are the outputs of the multiplication circuit. Circuit, and a second absolute value limiter that inputs the output current command value of the inverse pq arithmetic circuit and outputs the output current command value limited to the rating of the power conversion device to the power conversion device It is a control device of a power converter for power and harmonic compensation.

[0012]

According to the present invention, the optimum limit value to be applied to each power component to be compensated divided on the pq axis is calculated,
By controlling the limiter for each power component according to the optimum value, the device capacity can be maximized.

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing a first embodiment of the present invention, in which 1 is a current command ic1. Is a current command arithmetic circuit for dividing the electric power obtained from the system voltage and the current iL detected by the current transformer into an instantaneous real power p and an instantaneous imaginary power q.
q The power divided by the arithmetic circuit 3 is the harmonic power component Ph,
Qh, a power calculation circuit 4 for discriminating into the reactive power component Qo, components Ph, Qh and Qo discriminated by the power calculation circuit 4, a limiter 5 on the pq axis for limiting the components, and components Ph1, Qh1 limited by the limiter 5. enter the Qo1, inverse pq arithmetic circuit 6 converts the output current command value ics ^*, enter the converted output current command value ics ^* by the inverse pq arithmetic circuit 6, the output current is limited to devices rated command ic1 ^* It is composed of an absolute value limiter 7 for outputting.

FIG. 2 shows an example of the configuration of the limiter 5 on the pq axes shown in FIG. Reference numeral 11 is a vector calculation circuit, 12 is a peak detection circuit, 13 is a harmonic compensation capacity calculation device, 14 is an absolute value limiter, 15 is a harmonic compensation gain calculation device, and 17 is a multiplication circuit.

Here, the harmonic compensation capacity calculation device 13 is
The reactive power component Qo discriminated by the power calculation circuit 4 is input, and when the reactive power component exceeds a certain value, a gain inversely proportional to the reactive power component is output. Also,
The harmonic compensation gain calculation device 15 includes a peak detection circuit 12
Enter the peak value of the effective value of the harmonic power held in
A constant gain is output when the value is less than or equal to the limit value that is varied by the gain from the harmonic compensation capacity calculation device 13, and when the limit value is exceeded, 2 is applied to the peak value of the effective value of the harmonic power.
It outputs a gain that is inversely proportional to the following curve. The absolute value limiter 14 inputs the reactive power component discriminated by the power calculation circuit 4, and is directly proportional to the reactive power component when the absolute value of the limit value which is varied by the gain from the harmonic compensation capacity calculation device 13 is equal to or less than the absolute value. Is output, and a constant gain is output when the absolute value of the limit value is exceeded.

Hereinafter, the operation of the control device of the reactive power and harmonic compensating power converter configured as described above will be described. In FIG. 1, the electric power obtained from the system voltage and the detected current iL is divided into an instantaneous actual power p and an instantaneous imaginary power q by the pq arithmetic circuit 3, and this is calculated by the electric power arithmetic circuit 4.
The harmonic power components Ph and Qh and the reactive power component Qo are discriminated. The size of each discriminated component is limited by the limiter 5 on the pq axes. Component P of limited size
The inverse pq arithmetic circuit 6 converts h1, Qh1, and Qo1 into the output current command value ic ^* . Output current command value ic ^*
Is limited to the device rating by the absolute value limiter 7, is input to the inverter 2 as the output current command ic1 ^* , and the current ic is output from the inverter 2.

Next, referring to FIG. 2, the operation of the limiter 5 on the pq axes will be described.

The magnitudes of the harmonic power components Ph and Qh are calculated by the vector calculation circuit 11, and the peak value is detected and held by the peak detection circuit 12. Then, when the output of the reactive power exceeds a certain value by the harmonic compensation capacity calculation device 13, the limit value of the harmonic compensation gain calculation device 15 is lowered, and the gain according to the limit value is output. This gain is multiplied by the harmonic power components Ph and Qh, and the harmonic power command values Ph1 and Qh1 are output within the range of the lowered limit value. At this time, in the reactive power component Qo, the limit value of the absolute value limiter 14 is raised.

According to the first embodiment described above, the harmonic power command values Ph1, Qh1 and the reactive power command value Qo1 are kept below the set values, and the output current command value ic is also kept below the set value. .

From the above, the harmonic power command value,
If the sum of the upper limits of the reactive power command values is set within the device rating, the output current command value will not exceed the device rating.

The capacity of the device can be effectively used by dynamically changing the upper limit of the harmonic command value and the upper limit of the reactive power command value according to changes in load and operating conditions.

FIG. 3 is a block diagram showing a second embodiment of the present invention, which is an embodiment in the case where the harmonic power components are divided by giving preferential residence. The difference from the first embodiment described above is that a reactive power compensation capacity calculation device 131 is provided in a portion corresponding to the harmonic compensation capacity calculation device 13 in FIG.

Here, the reactive power compensation capacity calculation device 131
Is to input the peak value of the effective value of the harmonic power held in the peak detection circuit 12 and output a gain in inverse proportion to the peak value when the peak value exceeds a certain value. Harmonic compensation gain computing device 1 used in this embodiment
5 inputs the peak value of the effective value of the harmonic power held by the peak detection circuit 12, and the reactive power compensation capacity calculation device 1
A constant gain is output when the value is less than or equal to the limit value that is variable by the gain from 31, and a gain that is inversely proportional to a quadratic curve with respect to the peak value of the effective value of the harmonic power is output when the limit value is exceeded. It is a thing. Further, the absolute value limiter 14 used in this embodiment inputs the reactive power component discriminated by the power computing circuit 4, and the reactive power compensation capacity computing device 131.
A gain that is directly proportional to the reactive power component is output when it is less than or equal to the absolute value of the limit value that varies depending on the gain from, and a constant gain is output when the absolute value of the limit value is exceeded.

In the second embodiment, the magnitudes of high frequency powers of the harmonic power components Ph and Qh are calculated by the vector calculation circuit 11, and the peak value of the calculated value is detected and held by the peak detection circuit 12. When the high frequency power held in the peak detection circuit 12 exceeds a certain value, the reactive power compensation capacity calculation device 131 lowers the limit value of the reactive power with respect to the absolute value limiter 14, and the gain k is increased according to this limit value.
3 is output to the multiplication circuit 17, and the multiplication circuit 17 multiplies the gain k3 and the reactive power component Qo, and outputs the reactive power command value Qo1 within the range of the limit value.

Further, when the high frequency power held in the peak detection circuit 12 exceeds a certain value, the limit value is raised in the harmonic compensation gain calculation device 15, and the gains kl and k2 according to the limit value are multiplied by the multiplication circuit. 17 are output. The gains k1 and k2 are multiplied by the harmonic power components Ph and Qh in the multiplication circuit 17, and the harmonic power command values Ph1 and Qh1 are output within the range of the limit value.

FIG. 4 is a block diagram showing a third embodiment of the present invention, which is an example in which the upper limit values of the harmonic power component and the reactive power component are monitored and divided. The difference from the first embodiment is that the harmonic compensation capacity calculation device 13 of FIG. 2 or the reactive power compensation capacity calculation device 131 of FIG. The point is that the compensation capacity calculation device 1311 including the device 13 or the reactive power compensation capacity calculation device as shown in FIG. 3 is provided.

Here, the harmonic compensation capacity computing device of the compensation capacity computing device 1311 inputs the reactive power component Qo discriminated by the power computing circuit 4, and when the reactive power component Qo exceeds a certain value, The gain is inversely proportional to the reactive power component.

In addition, the reactive power compensation capacity arithmetic unit of the compensation capacity arithmetic unit 1311 inputs the peak value of the effective value of the harmonic power held in the peak detection circuit 12, and the peak value exceeds a certain value. At this time, a gain that is inversely proportional to the peak value is output.

Further, the harmonic compensation gain computing device 15 used in this embodiment inputs the peak value of the effective value of the harmonic power held in the peak detection circuit 12, and the harmonic compensation capacitance computing device or the above A constant gain is output when the value is less than or equal to the limit value that is varied by the gain from the reactive power compensation capacity calculation device, and when the limit value is exceeded, the peak value of the effective value of the harmonic power is inversely proportional to a quadratic curve. It outputs the gain to

Further, the absolute value limiter 14 used in this embodiment inputs the reactive power component discriminated by the power calculation circuit 4 and uses the gain from the harmonic compensation capacity calculation device or the reactive power compensation capacity calculation device. A gain that is directly proportional to the reactive power component is output when the absolute value of the variable limit value is less than the absolute value, and a constant gain is output when the absolute value of the limit value is exceeded.

In the third embodiment, the magnitudes of the harmonic powers of the harmonic power components Ph and Qh are calculated by the vector calculation circuit 11, and the peak value of the harmonic power is detected and held by the peak detection circuit 12. It When the harmonic power held by the peak detection circuit 12 exceeds a certain value,
The absolute value limiter 14 is set by the compensation capacity calculation device 1311.
At, the limit value of the reactive power is lowered, the gain k3 according to the limit value is output to the multiplication circuit 17, and the multiplication circuit 1
In 7, the gain k3 is multiplied by the reactive power component Qo, and the reactive power command value Qo1 is output within the range of the limit value.

Similarly, when the reactive power component Qo exceeds a fixed value, the limit value of the harmonic compensation gain calculation device 15 is lowered, and the gains kl and k2 according to the limit value are output to the multiplication circuit 17, respectively. To be done. The gains kl and k2 are
In the multiplication circuit 17, the harmonic power components Ph and Qh are multiplied, and within the limit value, the harmonic power command values Ph1 and Qh.
h1 is output. In this way, when the output of both the harmonic power component and the reactive power component exceeds a certain value,
The limit value is controlled so that the capacity is divided at a certain ratio.

[0034]

According to the present invention described above, the capacity of the device can be effectively used by controlling the upper limits of the harmonic command value and the reactive power command value and dynamically changing them, and the reactive power can be downsized. It is also possible to provide a control device for a power converter for harmonic compensation.

[Brief description of drawings]

FIG. 1 is a principle configuration diagram of a control device for a reactive power and harmonic compensation power converter according to the present invention.

FIG. 2 shows a first embodiment according to the present invention,
FIG. 6 is a block diagram in the case of using a limiter on the pq axes and dynamic division of an upper limit.

FIG. 3 is a block diagram showing a second embodiment according to the present invention.

FIG. 4 is a block diagram in the case of using a limiter on the pq axes of FIG. 3 and dynamic division of an upper limit.

FIG. 5 is a block diagram by a limiter on a pq axis of a control device of a conventional power conversion device for reactive power and harmonic compensation.

6 is a block diagram showing a limiter on the pq axes of FIG. 5. FIG.

[Explanation of symbols]

1 ... Electric power command arithmetic circuit, 2 ... Inverter, 3 ... Pq arithmetic circuit, 4 ... Electric power arithmetic circuit, 5 ... Limiter on pq axis, 6
Inverse pq arithmetic circuit, 7 ... Absolute value limiter, 11 ... Vector arithmetic circuit, 12 ... Peak detection circuit, 13 ... Harmonic compensation capacity arithmetic device, 131 ... Reactive power compensation capacity arithmetic device, 1
311 ... Compensation capacity calculation device, 14 ... Absolute value limiter, 1
5 ... Harmonic compensation gain calculator, 17 ... Multiplier circuit.

Front page continuation (58) Fields surveyed (Int.Cl. ⁷ , DB name) H02M 7/48 H02J 3/46

Claims (3)

(57) [Claims] 1. A controller for a reactive power and harmonic compensating power converter for compensating for reactive power and harmonics in a power system, which takes in a voltage and a detected current of the power system and calculates based on this. The instantaneous real power p and the instantaneous imaginary power q
A power calculation circuit for discriminating the power divided by the pq calculation circuit into a harmonic power component and a reactive power component, and a harmonic power component discriminated by the power calculation circuit as an input. A vector calculation circuit for calculating the effective value of the wave power, a peak detection circuit for detecting and holding the peak value of the effective value of the harmonic power calculated by the vector calculation circuit, and a reactive power component discriminated by the power calculation circuit. Enter
A harmonic compensation capacitance calculation device that outputs a gain that is inversely proportional to the reactive power component when the reactive power component exceeds a certain value; and a peak value of the effective value of the harmonic power held by the peak detection circuit. Is input, a constant gain is output when the value is equal to or less than a limit value that is varied by the gain from the harmonic compensation capacity calculation device, and when the limit value is exceeded, 2 is applied to the peak value of the effective value of the harmonic power. A harmonic compensation gain calculation device that outputs a gain inversely proportional to the following curve, and input the reactive power component discriminated by the power calculation circuit,
A gain that is directly proportional to the reactive power component is output when the absolute value of the limit value that is changed by the gain from the harmonic compensation capacitance calculation device is less than or equal to the absolute value, and a constant gain is output when the absolute value of the limit value is exceeded. A first absolute value limiter for determining a harmonic power command value from the product of the harmonic power component discriminated by the power calculation circuit and the gain of the harmonic compensation gain calculation device, and the reactive power component and the A multiplication circuit for obtaining the reactive power command value from the product of the gain which is the output of the absolute value limiter of 1, and the harmonic power command value and the reactive power command value which are the outputs of the multiplication circuit are input to output the output current command value. An inverse pq arithmetic circuit to be obtained, and a second absolute value limit for inputting the output current instruction value of the inverse pq arithmetic circuit and outputting the output current instruction value limited to the rating of the electric power converter to the electric power converter. Control device for reactive power and harmonic compensation power conversion device having data and, a. 2. A controller for a reactive power and harmonic compensating power converter for compensating for reactive power and harmonics in a power system, wherein a voltage and a detected current of the power system are fetched and calculated based on this. The instantaneous real power p and the instantaneous imaginary power q
A power calculation circuit for discriminating the power divided by the pq calculation circuit into a harmonic power component and a reactive power component, and a harmonic power component discriminated by the power calculation circuit as an input. A vector calculation circuit for calculating the effective value of the wave power, a peak detection circuit for detecting and holding the peak value of the effective value of the harmonic power calculated by the vector calculation circuit, and a harmonic power held by the peak detection circuit A peak value of the effective value of, and outputs a gain in inverse proportion to the peak value when the peak value exceeds a certain value, and a harmonic held by the peak detection circuit. The peak value of the effective value of the wave power is input, a constant gain is output when the value is equal to or less than the limit value that is changed by the gain from the reactive power compensation capacity calculation device, and the high value is output when the limit value is exceeded. A harmonic compensation gain calculation unit for outputting the inverse proportional gain by a quadratic curve with respect to the peak value of the effective value of the wave power to enter the reactive power component which is discriminated by the power calculation circuit,
A gain that is directly proportional to the reactive power component is output when the absolute value of the limit value that is changed by the gain from the reactive power compensation capacity calculation device is less than or equal to the absolute value, and a constant gain is output when the absolute value of the limit value is exceeded. A first absolute value limiter for determining a harmonic power command value from the product of the harmonic power component discriminated by the power calculation circuit and the gain of the harmonic compensation gain calculation device, and the reactive power component and the A multiplication circuit for obtaining the reactive power command value from the product of the gain which is the output of the absolute value limiter of 1, and the harmonic power command value and the reactive power command value which are the outputs of the multiplication circuit are input to output the output current command value. An inverse pq arithmetic circuit to be obtained, and a second absolute value resistor for inputting the output current command value of the inverse pq arithmetic circuit and outputting the output current command value limited to the rating of the power converter to the power converter. Jitter and the control device of the reactive power and harmonic compensation power converter provided with the. 3. A controller for a reactive power and harmonic compensating power converter for compensating for reactive power and harmonics in a power system, which takes in a voltage and a detected current of the power system and is operated based on this. The instantaneous real power p and the instantaneous imaginary power q
A power calculation circuit for discriminating the power divided by the pq calculation circuit into a harmonic power component and a reactive power component, and a harmonic power component discriminated by the power calculation circuit as an input. A vector calculation circuit for calculating the effective value of the wave power, a peak detection circuit for detecting and holding the peak value of the effective value of the harmonic power calculated by the vector calculation circuit, and a reactive power component discriminated by the power calculation circuit. Enter
A harmonic compensation capacitance calculation device that outputs a gain that is inversely proportional to the reactive power component when the reactive power component exceeds a certain value; and a peak value of the effective value of the harmonic power held by the peak detection circuit. Of the effective value of the harmonic power held by the peak detection circuit, and a reactive power compensation capacity calculation device that outputs a gain in inverse proportion to the peak value when the peak value exceeds a certain value. When a peak value is input, a constant gain is output when the peak value is less than or equal to a limit value that is changed by the gain from the harmonic compensation capacity calculation device or the reactive power compensation capacity calculation device, and when the limit value is exceeded, the harmonic power is output. A harmonic compensation gain calculation device that outputs a gain that is inversely proportional to a quadratic curve with respect to the peak value of the effective value of, and a reactive power component discriminated by the power calculation circuit,
When the absolute value of the limit value that is changed by the gain from the harmonic compensation capacity calculation device or the reactive power compensation capacity calculation device is less than or equal to the absolute value, a gain that is directly proportional to the reactive power component is output, and the absolute value of the limit value is A first absolute value limiter that outputs a constant gain when exceeding, a harmonic power command value is obtained from the product of the harmonic power component discriminated by the power calculation circuit and the gain of the harmonic compensation gain calculation device. A multiplying circuit that obtains a reactive power command value from a product of the reactive power component and a gain that is an output of the first absolute value limiter; and a harmonic power command value and a reactive power command value that are outputs of the multiplying circuit. An inverse pq arithmetic circuit for inputting and obtaining an output current instruction value, and an output current instruction value limited to the rating of the power converter by inputting the output current instruction value of the inverse pq arithmetic circuit. Second absolute value control unit of the reactive power and harmonic compensation power conversion apparatus comprising a limiter, the output to the conversion device.