JP6901911B2 - Control device for static power compensator - Google Patents

Description

The present invention relates to a control device that controls a static power compensator connected to a power system.

A power system in which a distributed power source such as a photovoltaic power generation system is connected to a power system is used. In such a power system, if not properly controlled, the system voltage of the power system may deviate from the proper range. Therefore, by connecting a static power compensator for flowing arbitrary reactive power to the power system to the power system, deviation from the proper range of the system voltage is suppressed (see, for example, Patent Document 1).

JP-A-2007-20306

In recent years, due to the increase in energy generated by photovoltaic power generation and the increase in the load connected to the power system, static VAR compensators have not only basic functions such as voltage control and power factor control of the power system, but also imbalance compensation. It is required to have a plurality of functions such as control and harmonic suppression control. Here, there is room for consideration of configurations for realizing various controls required for the static VAR compensator such as voltage control, unbalanced compensation control, and harmonic suppression control.

An object of the present invention is to provide a control device for a static power compensator capable of solving the above-mentioned problems and realizing various controls such as voltage control, imbalance compensation control, and harmonic suppression control.

In order to solve the above problems, the control device of the ineffective power compensating device according to the present invention is a control device that controls the ineffective power compensating device connected to the power system, and obtains the ineffective current output by the ineffective power compensating device. The voltage magnitude controller that outputs the instructed invalid current command and the output current of the invalid power compensator are orthogonal to the direction of the interconnection point voltage that is the voltage at the connection point between the power system and the ineffective power compensator. The invalid current component is provided with an invalid current controller that controls the invalid power compensator so that the invalid current component follows the invalid current command, and the voltage magnitude controller includes the voltage command of the interconnection point voltage and the said. A voltage deviation calculator that calculates the deviation from the magnitude of the interconnection point voltage, and when the deviation is equal to or greater than the upper limit of the predetermined dead zone, the deviation is output by subtracting the upper limit from the deviation, and the deviation is output. Is equal to or less than the lower limit of the dead zone, a value obtained by subtracting the lower limit from the deviation is output, and when the deviation is larger than the lower limit and smaller than the upper limit, 0 is output. When the outputs of the dead band detector and the voltage dead band detector are not 0, the output of the voltage dead band detector is proportionally integrated and amplified and output as the invalid current command, and the output of the voltage dead band detector is 0. In some cases, it includes an error amplifier that brings the invalid current command closer to 0 with a predetermined time constant.

Further, in order to solve the above problems, the control device of the invalid power compensation device according to the present invention is a control device that controls the invalid power compensation device connected to the power system, and the invalid power compensation device outputs the invalid power. Direction of interconnection point voltage, which is the voltage at the connection point between the power system and the ineffective power compensator, of the output current of the ineffective power compensator and the voltage magnitude controller that outputs the ineffective current command that indicates the current. The voltage magnitude controller includes an invalid current controller that controls the invalid power compensator so that the invalid current component orthogonal to the invalid current component follows the invalid current command, and the voltage magnitude controller receives the input voltage command. A primary lag filter that outputs a voltage command that has undergone primary lag processing, a proportional integral amplification of the deviation between the voltage command output from the primary lag filter and the magnitude of the interconnection point voltage, and output as the invalid current command. When the error amplifier and the invalid current command output by the error amplifier are equal to or larger than the upper limit value of the dead zone of the invalid current, the lower limit voltage command is input to the primary delay filter and output by the error amplifier. When the invalid current command is equal to or less than the lower limit value of the dead band, the upper limit voltage command is input to the primary delay filter, and the invalid current command output by the error amplifier is larger than the lower limit value. If it is smaller than the upper limit value, a filter output switch that inputs the output of the first-order lag filter to the first-order lag filter is provided.

Further, in order to solve the above problems, the control device of the ineffective power compensating device according to the present invention is a control device that controls the inactive power compensating device connected to the power system, and is the power system and the ineffective power compensating device. A dq coordinate system consisting of orthogonal d-axis and q-axis that rotates in the forward direction at the frequency of the power system by converting the interconnection point voltage, which is the voltage at the connection point with, with a negative voltage phase. A dq coordinate voltage converter that outputs a voltage vector of components, and a phase adjuster that outputs the voltage phase so that the average value of the q-axis components of the voltage vector becomes 0 in a half cycle of the frequency of the power system. And, the voltage vector of the component of the xyb coordinate system including the orthogonal xb axis and the yb axis which rotate in the opposite direction at the frequency of the power system, which is obtained by converting the interconnection point voltage with the rotational coordinates in the voltage phase. , An unbalanced voltage detector that outputs an unbalanced voltage vector that is an average value in the half cycle, and each component of the xyb coordinate system of the unbalanced voltage vector are proportionally integrated and amplified and output as an unbalanced compensation current command. The unbalanced compensating current command generator and the unbalanced power compensating device are controlled so that each component of the xyb coordinate system of the output current of the unbalanced power compensating device follows each component of the unbalanced compensating current command. It includes a balanced current controller.

Further, in order to solve the above problems, the control device of the ineffective power compensating device according to the present invention is a control device that controls the inactive power compensating device connected to the power system, and is the power system and the ineffective power compensating device. A dq coordinate system consisting of orthogonal d-axis and q-axis that rotates in the forward direction at the frequency of the power system by converting the interconnection point voltage, which is the voltage at the connection point with, with a negative voltage phase. A dq coordinate voltage converter that outputs a voltage vector of components, and a phase adjuster that outputs the voltage phase so that the average value of the q-axis components of the voltage vector becomes 0 in a half cycle of the frequency of the power system. And, the voltage vector of the component of the xyb coordinate system including the orthogonal xb axis and the yb axis which rotate in the opposite direction at the frequency of the power system, which is obtained by converting the interconnection point voltage with the rotational coordinates in the voltage phase. , The unbalanced voltage detector that outputs the unbalanced voltage vector which is the average value in the half cycle, and the magnitude when the magnitude of the unbalanced voltage vector is less than the width of the dead zone of the unbalanced voltage. When an output voltage vector of 0 is output and the magnitude of the unbalanced voltage vector is equal to or greater than the width of the dead zone, the width of the dead zone of the unbalanced voltage is large in the same direction as the unbalanced voltage vector. An unbalanced voltage dead zone detector that outputs a vector having a value as an output voltage vector, and if the magnitude of the output voltage vector is not 0, each component of the output voltage vector is proportionally integrated and amplified to compensate for the unbalanced compensation current. It is output as a command, and when the magnitude of the output voltage vector is 0, the unbalance compensation current command outputs an unbalance compensation current command so that the unbalance compensation current command approaches 0 with a predetermined time constant. An unbalanced current controller that controls the unbalanced power compensator so that each component of the xyb coordinate system of the output current of the unbalanced power compensator follows each component of the unbalanced compensating current command. , Equipped with.

Further, in order to solve the above problems, the control device of the ineffective power compensating device according to the present invention is a control device that controls the inactive power compensating device connected to the power system, and is the power system and the ineffective power compensating device. A dq coordinate system consisting of orthogonal d-axis and q-axis that rotates in the forward direction at the frequency of the power system by converting the interconnection point voltage, which is the voltage at the connection point with, with a negative voltage phase. A dq coordinate voltage converter that outputs a voltage vector of components, and a phase adjuster that outputs the voltage phase so that the average value of the q-axis components of the voltage vector becomes 0 in a half cycle of the frequency of the power system. And the orthogonal xn that rotates at a frequency n times the frequency of the power system obtained by converting the interconnection point voltage at an angle of n (n is a multiple of 6 ± 1) times the voltage phase. Each of the harmonic voltage detector that outputs the nth harmonic voltage vector, which is the average value in the half cycle of the voltage vector of the component of the xyn coordinate system consisting of the axis and the yn axis, and the nth harmonic voltage vector. Each component of the xyn coordinate system of the output current of the ineffective power compensator and the harmonic suppression current command generator that proportionally integrates and amplifies the components and outputs them as the nth harmonic suppression current command is the nth harmonic. A harmonic current controller that controls the ineffective power compensator so as to follow each component of the suppression current command is provided.

Further, in order to solve the above problems, the control device of the ineffective power compensating device according to the present invention is a control device that controls the inactive power compensating device connected to the power system, and is the power system and the ineffective power compensating device. A dq coordinate system consisting of orthogonal d-axis and q-axis that rotates in the forward direction at the frequency of the power system by converting the interconnection point voltage, which is the voltage at the connection point with, with a negative voltage phase. A dq coordinate voltage converter that outputs a voltage vector of components, and a phase adjuster that outputs the voltage phase so that the average value of the q-axis components of the voltage vector becomes 0 in a half cycle of the frequency of the power system. And the orthogonal xn that rotates at a frequency n times the frequency of the power system obtained by converting the interconnection point voltage at an angle of n (n is a multiple of 6 ± 1) times the voltage phase. A harmonic voltage detector that outputs the nth harmonic voltage vector, which is the average value in the half cycle of the voltage vector of the component of the xyn coordinate system consisting of the axis and the yn axis, and the magnitude of the nth harmonic voltage vector. When is less than the width of the dead zone of the nth harmonic voltage, an output voltage vector having a magnitude of 0 is generated, and the magnitude of the nth harmonic voltage vector is the nth harmonic voltage. If it is equal to or greater than the width of the dead band, a vector having the size of the predetermined dead band of the nth harmonic voltage in the same direction as the nth harmonic voltage vector is subtracted from the nth harmonic voltage vector. The nth harmonic voltage vector generator with a dead band that outputs as an output voltage vector, and when the magnitude of the output voltage vector is not 0, each component of the output voltage vector is proportionally integrated and amplified to suppress the nth harmonic. It is output as a current command, and when the magnitude of the output voltage vector is 0, the nth harmonic suppression current command is output so that the nth harmonic suppression current command approaches 0 with a predetermined time constant. The ineffective power compensator so that each component of the xyn coordinate system of the output current of the nth harmonic suppression current command and the output current of the ineffective power compensator follows each component of the nth harmonic suppression current command. It is equipped with a harmonic current controller that controls the voltage.

Further, in the control device of the ineffective power compensating device according to the present invention, the harmonic current controller is an average value of the current vectors of the output currents of the ineffective power compensating devices for each component of the xyn coordinate system in the half cycle. The deviation between the nth harmonic current detector that outputs the nth harmonic current vector, each component of the nth harmonic suppression current command, and each component of the nth harmonic current vector is proportionally integrated and amplified. The xyn coordinate system integrator, the nth harmonic dq coordinate current converter that converts the nth harmonic suppression current command into the components of the dq coordinate system and outputs the nth harmonic, and the xyn coordinate system integrator. The nth harmonic dq coordinate voltage converter that converts the output into the components of the dq coordinate system and outputs the output is provided, and each component of the dq coordinate system of the output current of the ineffective power compensator is detected and output. A dq coordinate current controller that proportionally integrates and amplifies the deviation between each component of the output of the current detector, the nth harmonic dq coordinate current converter, and each component of the output of the current detector, and outputs the current controller. It is preferable to further include a voltage command calculator that outputs the sum of the output of the harmonic current controller and the output of the dq coordinate current controller as a command value of the output voltage of the ineffective power compensator.

Further, in the control device of the ineffective power compensating device according to the present invention, the inactive power compensating device is connected to a three-phase power converter that outputs a voltage according to a command value and one end to the output of the three-phase power converter. The converter side reactor, the connected filter capacitor connected to the other end of the converter side reactor, and the system side where one end is connected to one end of the filter capacitor and the other end is connected to the power system. The harmonic current controller includes a reactor or a transformer, and the harmonic current controller estimates a current flowing through the filter capacitor based on the filter voltage detector that detects the filter voltage that is the voltage of the filter capacitor and the capacitor voltage. Harmonic current command that corrects the capacitor current estimator and the nth harmonic suppression current command with the current, and generates and outputs a reactor current command that indicates the reactor current that is the current flowing through the converter side reactor. A corrector, an nth harmonic current detector that outputs an nth harmonic current vector that is an average value in the half cycle of the current vector of each component of the xyn coordinate system of the reactor current, and the nth harmonic The xyn coordinate system integrator that proportionally integrates and amplifies the deviation between each component of the wave suppression current command and each component of the nth harmonic current vector and outputs the deviation, and the dq coordinate system that outputs the nth harmonic suppression current command. The nth harmonic dq coordinate current converter that converts and outputs the components of the dq coordinate system, and the nth harmonic dq coordinate voltage converter that converts the output of the xyn coordinate system integrator into the components of the dq coordinate system and outputs it. A current detector that detects and outputs each component of the dq coordinate system of the output current of the ineffective power compensator, each component of the output of the nth harmonic dq coordinate current converter, and the current. The ineffective power is the sum of the dq coordinate current controller that proportionally integrates and amplifies the deviations from each component of the detector output, the output of the harmonic current controller, and the output of the dq coordinate current controller. It is preferable to include a voltage command calculator that outputs as a command value of the output voltage of the compensator.

Further, in the control device of the static power compensator according to the present invention, the static VAR compensator is
A three-phase power converter that outputs a voltage according to a command value, a converter-side reactor whose one end is connected to the output of the three-phase power converter, and a connection that is connected to the other end of the converter-side reactor. From the magnitude of the filter voltage, which is the voltage of the filter capacitor, the filter capacitor is provided with a system-side reactor or transformer whose one end is connected to one end of the filter capacitor and the other end is connected to the power system. It is preferable to further include a voltage corrector that corrects the voltage drop due to the transformer and outputs the voltage as the interconnection point voltage.

According to the control device of the static power compensator according to the present invention, various controls such as voltage control, imbalance compensation control, and harmonic suppression control can be realized.

It is a figure which shows an example of the structure of the control device of the static power compensator which concerns on 1st Embodiment of this invention. It is a figure which shows an example of the structure of the voltage magnitude controller shown in FIG. It is a figure which shows an example of the structure of the error amplifier shown in FIG. It is a figure which shows another example of the structure of the error amplifier shown in FIG. It is a figure which shows another example of the structure of the error amplifier shown in FIG. It is a figure which shows another example of the structure of the error amplifier shown in FIG. It is a figure which shows another example of the structure of the voltage magnitude controller shown in FIG. It is a figure which shows an example of the structure of the unbalanced voltage controller shown in FIG. It is a figure which shows another example of the structure of the unbalanced voltage controller shown in FIG. It is a figure which shows an example of the structure of the harmonic voltage controller shown in FIG. It is a figure which shows another example of the structure of the harmonic voltage controller shown in FIG. It is a figure which shows another example of the structure of the harmonic current controller shown in FIG. It is a figure which shows an example of the structure of the dq coordinate current controller shown in FIG. It is a figure which shows an example of the structure of the control device of the static power compensator which concerns on 2nd Embodiment of this invention. It is a figure which shows an example of the structure of the high frequency current controller shown in FIG. It is a figure which shows an example of the structure of the dq coordinate current controller shown in FIG. It is a figure which shows an example of the structure of the control device of the static power compensator which concerns on 3rd Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described.

(First Embodiment)
FIG. 1 is a diagram showing an example of the configuration of the control device 10 according to the first embodiment of the present invention. The control device 10 according to the present embodiment controls the static VAR compensator device 2 which is connected to the power system 1 and adjusts the system voltage of the power system 1. The static power compensator 2 is composed of, for example, a three-phase power converter that outputs a three-phase voltage according to an input voltage command.

The control device 10 shown in FIG. 1 includes an interconnection point voltage detector 11, a current detector 12, a voltage magnitude detector 13, a voltage magnitude controller 14, a dq coordinate voltage converter 15, and phase adjustment. Instrument 16, unbalanced voltage detector 17, unbalanced voltage controller 18, harmonic voltage detector 19, harmonic voltage controller 20, harmonic current controller 21, dq coordinate current controller 22 And a dq coordinate voltage command calculator 23.

The interconnection point voltage detector 11 detects the interconnection point voltage, which is the voltage at the connection point between the power system 1 and the static VAR compensator 2, and outputs the detection results to the voltage magnitude detector 13 and the dq coordinate voltage converter 15. , Output to the unbalanced voltage detector 17 and the harmonic voltage detector 19.

The current detector 12 detects the output current i _{αβ of the static VAR} compensator 2 and outputs the detection result to the harmonic current controller 21 and the dq coordinate current controller 22.

_{The voltage magnitude detector 13 calculates the magnitude V l} of the interconnection point voltage detected by the interconnection point voltage detector 11 based on the following equation (1), and obtains the magnitude of the interconnection point voltage. V _l is output to the voltage magnitude controller 14. In equation (1), v _α is the α-axis component of the interconnection point voltage, and v _b is the β-axis component of the interconnection point voltage.

The voltage magnitude controller 14 generates a _{reactive current command i qfr} that indicates a reactive current component orthogonal to the direction of the interconnection point voltage (indicates the reactive current output by the reactive power compensator 2). Here, the voltage magnitude controller 14 generates the reactive current command i _{qfr so that the magnitude V l} of the interconnection point voltage output from the voltage magnitude detector 13 becomes a predetermined value. The voltage magnitude controller 14 outputs the generated reactive current command i _qfr to the dq coordinate current controller 22.

FIG. 2 is a diagram showing an example of the configuration of the voltage magnitude controller 14.

The voltage magnitude controller 14 shown in FIG. 2 includes a voltage deviation calculator 141, a voltage dead zone detector 142, and an error amplifier 143.

The voltage deviation calculator 141 obtains the deviation v _{err by subtracting the magnitude V l} of the interconnection point voltage from the interconnection _{point voltage command v ref,} which is the voltage command of the interconnection point voltage, and obtains the acquired deviation v _err . Output to the voltage dead zone detector 142.

The voltage dead zone detector 142 outputs _{the dead band voltage v dz} to the error amplifier 143 based on the following equation (2) using _{the deviation ver err output from the voltage deviation calculator 141.} In equation (2), v _dzH is the upper limit of the dead zone in which the system voltage is not controlled. Further, v _dzL is the lower limit value of the dead zone in which the voltage control of the system voltage is not performed.

As is clear from the equation (2), in the voltage dead zone detector 142, the deviation v _err is equal to or higher than the upper limit value v _{dzH of the} predetermined dead band (the range of the deviation v _err in which the voltage is not controlled according to the deviation v _err). In this case, the value obtained by subtracting the upper limit value v _{dzH of the dead band from the deviation v err} is output as the dead band voltage v _{dz. Further, when the deviation v err is equal to} or less than the lower limit value v dzL of the predetermined dead band, the voltage dead zone detector 142 outputs the value obtained by subtracting the lower limit value _{v dz L of the dead band from the deviation v err} as the dead band voltage v dz. .. Further, the voltage dead zone detector 142 outputs 0 as _{the dead band voltage v dz when the deviation v err} is larger than the lower limit value v _dzL of the dead band and smaller than the upper limit value v _dzH.

When the output of the voltage dead band detector 142 (dead band voltage v _dz ) is not 0, the error amplifier 143 proportionally integrates and amplifies the output of the voltage dead band detector 142 and uses the reactive current command i _qfr as the dq coordinate current controller 22. Output to. The error amplifier 143 when the output of the voltage dead band detector 142 is 0, generates a reactive current command i _QFR as reactive current command i _QFR approaches zero at a predetermined time constant, dq coordinate current controller Output to 22.

FIG. 3 is a diagram showing an example of the configuration of the error amplifier 143.

The error amplifier 143 shown in FIG. 3 includes a gain amplifier 301, a first-order lag filter 302, an adder 303, and an output switch 304.

The gain amplifier 301 multiplies the output of the voltage dead zone detector 142 (dead band voltage v _dz ) by kp and outputs the output to the adder 303.

The first-order lag filter 302 is a filter represented by the transfer function G1 represented by the following equation (3). In equation (3), s is the Laplace operator and Ti is the integration time. Further, A is a value that can be switched according to the output of the output switch 304.

The first-order lag filter 302 performs filter processing (first-order lag processing) by the transfer function G1 on _{the reactive current command i qfr, and outputs the result to the adder 303.}

The adder 303 outputs the sum of the output of the gain amplifier 301 (kp-multiplied dead band voltage v _dz ) and the output of the first-order lag filter 302 as a reactive current command i _qfr .

_{The output switch 304 outputs a gain K as A when the dead band voltage v dz} output from the voltage dead band detector 142 is 0, and 0 as A when the dead band voltage v _dz is not 0. Output.

Therefore, when the dead band voltage v _dz is not 0, the error amplifier 143 shown in FIG. 3 proportionally integrates and amplifies the _{dead band voltage v dz} and outputs it as _{a reactive current command i qfr.} Further, the error amplifier 143 sets the reactive current command i _qfr to approach 0 with the time constant T _{l = Ti / K when the dead band voltage v dz is 0.} The time constant T _l indicates the response speed when the reactive current command i _{qfr approaches 0.}

The configuration of the error amplifier 143 is not limited to the configuration shown in FIG. FIG. 4 is a diagram showing another example of the configuration of the error amplifier 143. In FIG. 4, the same reference numerals are given to the same configurations as those in FIG. 3, and the description thereof will be omitted.

The error amplifier 143 shown in FIG. 4 includes a gain amplifier 301, a first-order lag filter 302a, an adder 303a, an output switch 304a, and a multiplier 305.

The output switch 304a outputs a gain K to the multiplier 305 when _{the dead band voltage v dz} output from the voltage dead band detector 142 is 0, and sets 1 when the _{dead band voltage v dz is not 0.} Output to multiplier 305.

The multiplier 305 outputs a value obtained by multiplying the output (gain K or 1) of the output switch 304a by the reactive current command i _qfr to the first-order lag filter 302a.

The first-order lag filter 302a is a filter represented by a transfer function G = 1 / (1 + sTi). The first-order lag filter 302a performs filter processing (first-order lag processing) by the transfer function G on _{the reactive current command i qfr, and outputs the result to the adder 303a.}

The adder 303a outputs the sum of the output of the gain amplifier 301 (the dead band voltage v _dz multiplied by kp) and the output of the filter 302a as a reactive current command i _qfr .

Therefore, when the dead band voltage v _dz is not 0, the error amplifier 143 shown in FIG. 4 proportionally integrates and amplifies the _{dead band voltage v dz} and outputs it as _{a reactive current command i qfr.} Further, the error amplifier 143 sets the _{reactive current command i qfr} to approach 0 with the time constant T _l = Ti / (1-K) _{when the dead band voltage v dz is 0.}

FIG. 5 is a diagram showing another example of the configuration of the error amplifier 143. In FIG. 5, the same components as those in FIG. 3 are designated by the same reference numerals, and the description thereof will be omitted.

The error amplifier 143 shown in FIG. 5 includes a gain amplifier 301, first-order lag filters 302b-1, 302b-2, an adder 303b, and an output switch 304b.

The first-order lag filter 302b-1 is a filter represented by a transfer function G = 1 / (1 + sTi). _{The reactive current command i qfr} is input to the primary delay filter 302b-1, and the input (reactive current command i _qfr ) is filtered by the transfer function G = 1 / (1 + sTi) (primary delay processing) and output. Output to the switch 304b.

The first-order lag filter 302b-2 is a filter represented by a transfer function G = 1 / (1 + sTf). Here, Tf is a time constant. 0 is input to the primary delay filter 302b-2, the input is filtered by the transfer function G = 1 / (1 + sTf) (primary delay processing), and the input is output to the output switch 304b.

_{When the dead band voltage v dz} output from the voltage dead zone detector 142 is not 0, the output switch 304b outputs the output of the primary delay filter 302b-1 to the adder 303b. When the dead band voltage v _dz becomes 0, the input of the output switch 304b is preset to the value of the reactive current command i _{qfr at the moment when the dead band voltage v dz is switched to 0.} After that, the output switch 304b outputs the output of the primary delay filter 302b-2 to the adder 303b. As a result, the output of the output switch 304b approaches 0 with the time constant Tf from the preset value.

The adder 303a outputs the sum of the output of the gain amplifier 301 (the dead band voltage v _dz multiplied by kp) and the output of the output switch 304b as the reactive current command i _qfr .

Therefore, when the dead band voltage v _dz is not 0, the error amplifier 143 shown in FIG. 5 proportionally integrates and amplifies the _{dead band voltage v dz} and outputs it as _{a reactive current command i qfr.} Further, the error amplifier 143 sets the reactive current command i _qfr to approach 0 with the time constant T _{l = Tf when the dead band voltage v dz is 0.}

FIG. 6 is a diagram showing another example of the configuration of the error amplifier 143. In FIG. 6, the same reference numerals are given to the same configurations as those in FIG. 3, and the description thereof will be omitted.

The error amplifier 143 shown in FIG. 6 includes a gain amplifier 301, a first-order lag filter 302c, an adder 303c, an output switch 304c, and an integrator 306.

_{The integrator 306 integrates the dead band voltage v dz} output from the voltage dead zone detector 142 and outputs it to the output switch 304c.

The first-order lag filter 302c is a filter represented by a transfer function G = 1 / (1 + sTf). 0 is input to the primary delay filter 302c as an input, and the input is filtered by the transfer function G = 1 / (1 + Tfs) (primary delay processing) and output to the output switch 304c.

The output switch 304c outputs the output of the integrator 306 to the adder _{303c when the dead band voltage v dz} output from the voltage dead zone detector 142 is not 0. When the dead band voltage v _dz becomes 0, the input of the output switch 304c is preset to the value of the reactive current command i _{qfr at the moment when the dead band voltage v dz is switched to 0.} After that, the output switch 304c outputs the output of the first-order lag filter 302c to the adder 303c. As a result, the output of the output switch 304c approaches 0 with the time constant Tf from the preset value.

The adder 303c outputs the sum of the output of the gain amplifier 301 (kp-multiplied dead band voltage v _dz ) and the output of the output switch 304c as a reactive current command i _qfr .

Therefore, when the dead band voltage v _dz is not 0, the error amplifier 143 shown in FIG. 6 proportionally integrates and amplifies the _{dead band voltage v dz} and outputs it as _{a reactive current command i qfr.} Further, the error amplifier 143 sets the reactive current command i _qfr to approach 0 with the time constant T _{l = Tf when the dead band voltage v dz is 0.}

In the error amplifier 143 shown in FIG. 4, if the interconnection point voltage is constantly equal to _{or higher than the upper limit value v dzH of the} dead zone or lower than the lower limit value v _dzL , compensation is provided as long as the compensation capacity remains. The remaining compensation capacity becomes 0 or less. In this case, there is a problem that compensation cannot be performed if the interconnection point voltage further fluctuates momentarily.

In order to avoid such a problem, the steady voltage fluctuation of the power system 1 is connected in series with the power system 1 and automatically switches the tap of the transformer to adjust the voltage (SVR:). Compensation by Step Voltage Regulator), the ineffective power compensator 2 needs coordinated control that specializes in compensating for instantaneous voltage fluctuations in the power system 1.

FIG. 7 is a diagram showing another example of the configuration of the voltage magnitude controller 14. The voltage magnitude controller 14 shown in FIG. 7 is suitable for the above-mentioned cooperative control.

The voltage magnitude controller 14 shown in FIG. 7 includes a current dead zone detector 144, a filter output switch 145, a first-order lag filter 146, a subtractor 147, and an error amplifier 148.

_{When the reactive current command i qfr} is input and the input reactive current command i _{qfr is equal to} or higher than the upper limit value I qH of the reactive current dead band, the current dead zone detector 144 sets -1 to the filter output switch 145. Output. Further, the current dead zone detector 144 outputs 1 to the filter output switch 145 when _{the reactive current command i qfr is equal to or less than the lower limit value I qL} of the reactive current dead band. Further, the current dead zone detector 144 outputs 0 to the filter output switcher 145 when _{the reactive current command i qfr is larger than the lower limit value I qL} of the reactive current dead band and smaller than the upper limit value I _qH.

When the output of the current dead zone detector 144 is 1, the filter output switcher 145 outputs the upper limit voltage command _VH to the primary delay filter 146. Further, when the output of the current dead zone detector 144 is -1, the filter output switcher 145 outputs the lower limit voltage command _VL to the primary delay filter 146. Further, when the output of the current dead zone detector 144 is 0, the filter output switcher 145 inputs the output of the primary lag filter 146 to the primary lag filter 146. That is, when the reactive current command i _{qfr is equal to} or higher than the upper limit value I qH of the reactive current dead zone, the filter output switcher 145 inputs the lower limit voltage command _VL to the primary delay filter 146. Further, when the reactive current command i _{qfr is equal to or less than the lower limit value I qL} of the reactive current dead zone, the filter output switcher 145 inputs the upper limit voltage command V _H to the primary delay filter 146. Further, when the reactive current command i _qfr is smaller than the upper limit value I _{qH of} the dead band and larger than the lower limit value I _{qL of the} dead band, the filter output switcher 145 inputs the output of the first-order lag filter 146 to the first-order lag filter 146. To do.

The first-order lag filter 146 is a filter represented by a transfer function G = 1 / (1 + sTv). Here, Tv is a time constant. The primary delay filter 146 receives a voltage command from the filter output switch 145, and performs a filter process (primary delay process) by the transfer function G on the input voltage command to generate a voltage command. The first-order lag filter 146 outputs the generated voltage command to the filter output switch 145 and the subtractor 147. That is, the primary delay filter 146 outputs a voltage command obtained by performing primary delay processing on the input voltage command.

_{The subtractor 147 calculates a deviation obtained by subtracting the magnitude v l} of the interconnection point voltage from the voltage command output from the first-order lag filter 146, and outputs the calculated deviation to the error amplifier 148.

The error amplifier 148 proportionally integrates and amplifies the deviation output from the subtractor 147, and outputs the reactive current command i _qfr to the current dead zone detector 144 and the dq coordinate current controller 22. That is, the error amplifier 148 proportionally integrates and amplifies the deviation between the voltage command output from the first-order lag filter 146 and the magnitude v _{l of the interconnection point voltage, and outputs it as the reactive current command i qfr} .

According to the voltage magnitude controller 14 shown in FIG. 7, when the reactive current command i _{qfr is equal to} or higher than the upper limit value I qH of the reactive current dead zone, the lower limit voltage command _VL (can be set as a voltage command). _{The reactive current command i qfr} is generated according to the lower limit value). Further, reactive current command i _QFR is equal to or less than the lower limit value I _qL of the dead zone of the reactive current, the reactive current command i _QFR corresponding to the upper limit of the voltage command V _H (upper limit value that can be set as a voltage command) Generated. Therefore, when the reactive current command i _qfr deviates from the reactive current dead zone, the reactive current command i _qfr can be returned to the dead zone range in a predetermined time by the time constant Tv. That is, it is possible to compensate for the instantaneous voltage fluctuation of the power system 1. Therefore, the voltage magnitude controller 14 shown in FIG. 7 is suitable for the above-mentioned cooperative control.

Referring to FIG. 1 again, the dq coordinate voltage converter 15 converts the interconnection point voltage in the negative direction with the voltage phase θ (rotational coordinate conversion with the negative voltage phase (−θ)), and the dq coordinate system. It is output to the phase adjuster 16 as the voltage vector V _{dq of the component of.} Here, the dq coordinate system is a coordinate system including orthogonal d-axis and q-axis that rotate in the forward direction at the frequency of the power system 1. That is, the dq coordinate voltage converter 15 converts the interconnection point voltage into rotational coordinates with a negative voltage phase (−θ), and rotates forward at the frequency of the power system 1 with the orthogonal d-axis and q-axis. It is output as _{a voltage vector V dq} of the components of the dq coordinate system consisting of.

The phase adjuster 16 determines the voltage phase θ such that the average value of the q-axis components of _{the voltage vector V dq} output from the dq coordinate voltage converter 15 becomes 0 in the half cycle of the frequency of the power system 1. The phase adjuster 16 outputs the determined voltage phase θ to the dq coordinate voltage converter 15, the unbalanced voltage detector 17, the harmonic voltage detector 19, the harmonic current controller 21, and the dq coordinate current controller 22.

The unbalanced voltage detector 17 is an unbalanced voltage which is an average value of the voltage vectors of the components of the xyb coordinate system obtained by converting the interconnection point voltage with the voltage phase θ in a half cycle of the frequency of the power system 1. _{Detects the} vector V xyb. Here, the xyb coordinate system is a coordinate system including orthogonal xb axes and yb axes that rotate in opposite directions at the frequency of the power system 1. The unbalanced voltage detector 17 outputs the detected unbalanced voltage vector V _xyb to the unbalanced voltage controller 18.

The unbalanced voltage controller 18 proportionally integrates and amplifies each component of the _{unbalanced voltage vector V xyb} output from the unbalanced voltage detector 17 _{, and dq as the unbalanced compensation current command vector i xybr} (unbalanced compensation current command). Output to the coordinate current controller 22.

FIG. 8 is a diagram showing an example of the configuration of the unbalanced voltage controller 18.

The unbalanced voltage controller 18 shown in FIG. 8 includes an unbalanced compensation current command generator 181.

_{The unbalanced compensation current command generator 181 proportionally integrates and amplifies each component of the unbalanced voltage vector V xyb} output from the unbalanced voltage detector 17, so that each component of the unbalanced voltage vector V _xyb becomes 0. The imbalance compensation current command vector i _xybr is output to the dq coordinate current controller 22. That is, the unbalanced compensation current command generator 181 proportionally integrates and amplifies each component of the xyb coordinate system of the _{unbalanced voltage vector V xyb , and outputs the unbalanced compensation current command vector i xybr} (unbalanced compensation current command).

In FIG. 8, a configuration example of the unbalanced voltage controller 18 when the dead zone of the unbalanced voltage is not provided has been described, but the present invention is not limited to this.

FIG. 9 is a diagram showing another example of the configuration of the unbalanced voltage controller 18 when the dead zone of the unbalanced voltage is provided.

The unbalanced voltage controller 18 shown in FIG. 9 includes an unbalanced voltage vector generator 182 with a dead zone and an unbalanced compensation current command generator 185.

The unbalanced voltage vector generator 182 with _{a dead zone has a magnitude of 0 when the magnitude of the unbalanced voltage vector V xyb} output from the unbalanced voltage detector 17 is less than the width of the dead zone of the unbalanced voltage. The dead zone unbalanced voltage vector v _dzxyb (output voltage vector) is output to the unbalanced compensation current command generator 185. Further, the unbalanced voltage vector generator 182 with an unbalanced band has the same direction as the _{unbalanced voltage vector V xyb and is unbalanced when the magnitude of the unbalanced voltage vector V xyb} is equal to or larger than the width of the unbalanced voltage vector V _{xyb. The dead zone unbalanced voltage vector v dzxyb} (output voltage vector) having the magnitude of the dead zone width of the balanced voltage is output to the unbalance compensation current command generator 185.

The unbalanced voltage vector generator 182 with a dead zone includes an unbalanced voltage magnitude calculator 183 and an unbalanced voltage dead zone detector 184.

The unbalanced voltage magnitude calculator 183 calculates the magnitude v _{bvl of the unbalanced voltage vector V xyb} based on the following equation (4) and outputs it to the unbalanced voltage dead zone detector 184.

The unbalanced voltage dead zone detector 184 uses the unbalanced voltage vector V _xyb and the magnitude v _{bvl of the unbalanced voltage vector V xyb} output from the unbalanced voltage magnitude calculator 183 to obtain the following equation (5). ), The dead zone unbalanced voltage vector v _dzxyb is generated.

That is, in the unbalanced voltage dead zone detector 184, the magnitude v _bvl of the unbalanced voltage vector V xyb is in the unbalanced voltage dead zone (the range of the unbalanced voltage that does not _{perform the unbalanced compensation control according to the unbalanced voltage).} If it is less than the width, a dead zone unbalanced voltage vector v _dzxyb (output voltage vector) of zero magnitude is generated. Further, the unbalanced voltage dead zone detector 184 is unbalanced in the same direction as the _{unbalanced voltage vector V xyb when} the magnitude v _{bvl of the unbalanced voltage vector V xyb} is equal to or larger than the width of the unbalanced voltage dead zone. _Generates a deadband unbalanced voltage vector v dzxyb (output voltage vector) with a voltage deadband width v _bw.

The unbalanced voltage dead zone detector 184 outputs the generated dead zone unbalanced voltage vector v _dzxyb to the unbalanced compensation current command generator 185.

The unbalanced compensation current command generator 185 has, for example, the same configuration as the error amplifier 143 described with reference to FIGS. 3 to 6. However, the gain value is different. The unbalanced compensation current command generator 185 is a deadband unbalanced voltage vector when _{the magnitude of the deadband unbalanced voltage vector v dzxyb} (output voltage vector) output from the deadband unbalanced voltage vector generator 182 is not 0. Each component of v _dzxyb is proportionally integrated and amplified, and output to the dq coordinate current controller 22 as an unbalanced compensation current command vector i _xybr. Further, in the unbalanced compensation current command generator 185, _when the magnitude of the dead zone unbalanced voltage vector v dzxyb is 0, each component of the unbalanced compensation current command vector i _xybr is referred to with reference to FIGS. 3 to 6. _{The unbalanced compensation current command vector i xybr} that approaches zero at each time constant of the error amplifier 143 described above is output to the dq coordinate current controller 22.

Referring again to FIG. 1, the harmonic voltage detector 19 transforms the interconnection point voltage into rotational coordinates at an angle (nθ) n times the voltage phase θ, which is the power of the voltage vector of the components of the xyn coordinate system. _{The nth harmonic voltage vector V xyn} , which is the average in the half cycle of the frequency of the system 1, is generated. Here, the xyn coordinate system is a coordinate system including orthogonal xn axes and yn axes that rotate at a frequency n times that of the power system 1. n is, for example, 5,7,11,13 (n = 6m ± 1 (m is a natural number of 1 or more)). Therefore, the harmonic voltage detector 19 converts the 5th, 7th, 11th, and 13th harmonic voltages of the interconnection point voltage into DC components and extracts them when the frequency of the power system 1 is set to the 1st order. Then, it is output to the harmonic voltage controller 20. In FIG. 1, the 5th, 7th, 11th, and 13th harmonic voltages are collectively shown as the nth harmonic voltage vector V _xyn .

_{The harmonic voltage controller 20 proportionally integrates and amplifies the nth harmonic voltage vector V xyn} output from the harmonic voltage detector 19, so that each component of the nth harmonic voltage vector V _{xyn becomes 0. Generates the} nth harmonic compensation current command vector i xynr (nth harmonic current command). That is, the harmonic voltage controller 20 sets _{the static VAR compensator 2 so that each component of the xyn coordinate system of the output current i αβ} of the static VAR compensator 2 follows each component of the nth harmonic suppression current command. Control.

FIG. 10 is a diagram showing an example of the configuration of the harmonic voltage controller 20. The harmonic voltage controller 20 includes the configuration shown in FIG. 10 corresponding to the harmonics of each order.

The harmonic voltage controller 20 shown in FIG. 10 includes an nth harmonic suppression current command generator 201.

n harmonic suppression current command generator 201 is proportional integrating amplifier each component of the n-th harmonic voltage vector V _xyn, the n-th harmonic voltage n-th harmonic as the components of the vector V _xyn becomes 0 The compensation current command vector i _xynr is output to the harmonic current controller 21.

In FIG. 10, a configuration example of the harmonic voltage controller 20 in the case where the dead zone of the harmonic voltage is not provided has been described, but the present invention is not limited to this.

FIG. 11 is a diagram showing an example of the configuration of the harmonic voltage controller 20 when the dead zone of the harmonic voltage is provided. Also in FIG. 11, the harmonic voltage controller 20 includes the configuration shown in FIG. 11 corresponding to the harmonics of each order.

The harmonic voltage controller 20 shown in FIG. 11 includes an nth harmonic voltage vector generator 202 with a dead band and an nth harmonic suppression current command generator 205.

The nth harmonic voltage vector generator 202 with a dead band is used when _{the magnitude of the nth harmonic voltage vector V xyn} output from the harmonic voltage detector 19 is less than the width of the dead band of the nth harmonic voltage. _{Outputs the nth harmonic voltage vector V dzxyn} (output voltage vector) with a dead band of magnitude 0 to the nth harmonic suppression current command generator 205. Further, in the nth harmonic voltage vector generator 202 with a dead band, _when the magnitude of the nth harmonic voltage vector V xyn is equal to or larger than the width of the dead band of the nth harmonic voltage, the nth harmonic voltage vector _{Outputs the nth harmonic voltage vector V dzxyn} (output voltage vector) with a dead zone, which has the width of the dead zone of the nth harmonic voltage in the same direction as V xyn, to the nth harmonic suppression current command generator 205. ..

The nth harmonic voltage vector generator 202 with a dead band includes an nth harmonic voltage magnitude calculator 203 and an nth harmonic voltage dead band detector 204.

The nth harmonic voltage magnitude calculator 203 calculates the magnitude v _nvl of _{the nth harmonic voltage vector V xyn} output from the harmonic voltage detector 19 based on the following equation (6), and calculates the nth harmonic voltage magnitude calculator 203. Output to harmonic voltage dead zone detector 204.

The nth harmonic voltage dead zone detector 204 sets the nth harmonic voltage vector V _xyn and the magnitude v _{nvl of the nth harmonic voltage vector V xyn} output from the nth harmonic voltage magnitude calculator 203. _{The nth harmonic voltage vector V dzxyn} with a dead band is generated based on the following equation (7).

The nth harmonic suppression current command generator 205 has, for example, the same configuration as the error amplifier 143 described with reference to FIGS. 3 to 6. However, the gain value is different. The nth harmonic suppression current command generator 205 is used when _{the magnitude of the dead band nth harmonic voltage vector V dzxyn} (output voltage vector) output from the dead band nth harmonic voltage vector generator 202 is not 0. Proportionally integrates and amplifies each component of the _{nth harmonic voltage vector V dzxyn} with a dead band, and _{outputs the nth harmonic compensation current command vector i xynr} to the harmonic current controller 21. Further, in the nth harmonic suppression current command generator 205, _{when the magnitude of the nth harmonic voltage vector V dzxyn} with a dead band is 0, the nth harmonic voltage vector V dzxyn with a dead band is obtained from FIGS. _{The nth harmonic compensation current command vector i xynr} that approaches zero with the time constant of the error amplifier 143 described with reference to FIG. 6 is output to the harmonic current controller 21.

Referring to FIG. 1 again, the harmonic voltage controller 20 outputs the harmonic compensation current command vector generated for each of the 5th, 7th, 11th, and 13th harmonic voltages to the harmonic current controller 21. In FIG. 1, the harmonic compensation current command vectors generated for each of the 5th, 7th, 11th, and 13th harmonic voltages are collectively shown as the nth harmonic compensation current command vector i _xynr .

In the harmonic current controller 21, _{each component of the xyb coordinate system of the output current i αβ} of the static power compensator 2 is the nth harmonic compensation current command vector i _xynr (nth order) output from the harmonic voltage controller 20. The static VAR compensator 2 is controlled so as to follow each component of the harmonic current command).

FIG. 12 is a diagram showing an example of the configuration of the harmonic current controller 21. The harmonic current controller 21 includes the configuration shown in FIG. 12 corresponding to the harmonics of each order.

The harmonic current controller 21 shown in FIG. 12 includes an nth harmonic current detector 211, an nth harmonic current deviation calculator 212, an xyn coordinate system integrator 213, and an nth harmonic dq coordinate voltage converter. It includes 214 and an nth harmonic dq coordinate current converter 215.

The nth harmonic current detector 211 generates the _{nth harmonic current vector I xyn} , which is a current vector obtained by rotating _{the output current i αβ} of the invalid power compensator 2 detected by the current detector 12 with nθ. , Nth harmonic current is output to the current deviation calculator 212. That is, the nth harmonic current detector 211 is the nth harmonic which is the average value of the current vectors of each component of the xyn coordinate system of _{the output current i αβ of the static power compensator 2 in the half cycle of the frequency of the power system 1.} The wave current vector I _xyn is output.

The nth harmonic current deviation calculator 212 includes the nth harmonic compensation current command vector i _xynr output from the harmonic voltage controller 20 and the nth harmonic current output from the nth harmonic current detector 211. The deviation of each component from the vector I _xyn is calculated and output to the xyn coordinate system integrator 213.

The xyn coordinate system integrator 213 integrates the deviation output from the nth harmonic current deviation calculator 212 and outputs it to the nth harmonic dq coordinate voltage converter 214.

The nth harmonic dq coordinate voltage converter 214 converts the output of the xyn coordinate system integrator 213 into rotational coordinates with − (n + 1) θ to generate the _{nth harmonic dq coordinate voltage command vector v dqnr.} The nth harmonic dq coordinate voltage converter 214 outputs the generated nth harmonic dq coordinate voltage command vector v _dqnr to the dq coordinate voltage command calculator 23.

The nth harmonic dq coordinate current converter 215 transforms the nth harmonic compensation current command vector i _xynr output from the harmonic voltage controller 20 into rotational coordinates with − (n + 1) θ to convert the nth harmonic to the nth harmonic. dq coordinate current command vector i _dqnr is generated. The nth harmonic dq coordinate current converter 215 outputs the generated nth harmonic dq coordinate current command vector i _dqnr to the dq coordinate current controller 22.

Explaining with reference to FIG. 1 again, the harmonic current controller 21 transfers the nth (5th, 7th, 11th, 13th) harmonic dq coordinate current command vector i _dqnr to the dq coordinate current controller 22. Output. Further, the harmonic current controller 21 outputs the nth (5th, 7th, 11th, 13th) harmonic dq coordinate voltage command vector v _dqnr to the dq coordinate voltage command calculator 23.

In the dq coordinate current controller 22, the dq coordinate system current command obtained by converting the current command obtained by each control (voltage control, unbalance compensation control, harmonic suppression control) into the dq coordinate system is the invalid power compensation device 2. It operates to generate the _{invalid voltage command v qfbr} and the effective voltage command v _dfbr , which are voltage commands that match the output current i _{αβ converted into dq coordinates.} The dq coordinate current controller 22 outputs the generated invalid voltage command v _qfbr and effective voltage command v _dfbr to the dq coordinate voltage command calculator 23.

FIG. 13 is a diagram showing an example of the configuration of the dq coordinate current controller 22.

The dq coordinate current controller 22 shown in FIG. 13 includes an unbalanced dq coordinate converter 221, a total current command calculator 222, a dq coordinate converter 223, a dq coordinate current deviation calculator 224, and an invalid current controller 225. And an effective current controller 226.

The unbalanced dq coordinate converter 221 converts the unbalanced compensation current command vector i _xybr output from the unbalanced voltage controller 18 into rotational coordinates with the voltage phase θ, thereby converting the unbalanced dq coordinates, which is a vector of the dq coordinate system. The current command vector I _dqbr is generated and output to the total current command calculator 222.

As represented by the equation (8), the total current command calculator 222 adds the q-axis components of the current commands of each input dq coordinate to obtain the sum invalid current command i _qr as the dq coordinate current deviation calculator. Output to 224. Further, the total current command calculator 222 adds the d-axis components of the current commands of each input _{dq coordinate and outputs the sum effective current command idr} to the dq coordinate current deviation calculator 224. In equation (8), i _q5r is the q-axis component of the fifth harmonic dq coordinate current command vector i _dq5r. i _q7r is the q-axis component of the 7th harmonic dq coordinate current command vector i _dq7r. i _q11r is the q-axis component of the 11th harmonic dq coordinate current command vector i _dq11r. i _q13r is the q-axis component of the 13th harmonic dq coordinate current command vector i _dq13r. i _d5r is a d-axis component of the fifth harmonic dq coordinate current command vector i _dq5r. i _d7r is the d-axis component of the 7th harmonic dq coordinate current command vector i _dq7r. i _d11r is a d-axis component of the 11th harmonic dq coordinate current command vector i _dq11r. i _d13r is the q-axis component of the 13th harmonic dq coordinate current command vector i _dq13r.

The dq coordinate converter 223 converts the output current i _{αβ of the invalid power compensator 2 into the dq coordinate current vector I dq} , which is a vector of the dq coordinate system, by converting the output current i αβ in the negative direction in the voltage phase θ. The dq coordinate converter 223 outputs the q-axis component i _q and the d-axis component i _d of the dq coordinate current vector I _dq to the dq coordinate current deviation calculator 224.

The dq coordinate current deviation calculator 224 is composed of the sum invalid current command i _qr output from the sum current command calculator 222 and the q-axis component i _q of the _{dq coordinate current vector I dq} output from the dq coordinate converter 223. The deviation is output to the invalid current controller 225. Further, the dq coordinate current deviation calculation unit 224 is outputted from the sum current command calculator 222 total active current command i _dr and, in the dq coordinate current vector I _dq output from the dq coordinate converter 223 d-axis component i _d The deviation from and is output to the effective current controller 226.

The reactive current controller 225 proportionally integrates and amplifies the deviation of the q-axis component output from the dq coordinate current deviation calculator 224, and _issues a reactive voltage command v qfbr such that the deviation becomes 0 to the dq coordinate voltage command calculator 23. Output to. That is, the reactive current controller 225 compensates for the reactive power so that the reactive current component in the direction orthogonal to the direction of the interconnection point voltage of _{the output current i αβ} of the reactive power compensator 2 follows the _{reactive current command i qfr.} Control device 2.

The effective current controller 226 proportionally integrates and amplifies the deviation of the d-axis component output from the dq coordinate current deviation calculator 224, and _issues an effective voltage command v dfbr such that the deviation becomes 0 to the dq coordinate voltage command calculator 23. Output to.

Focusing on the compensation of the unbalanced voltage, the unbalanced compensation current command vector i _xybr is converted into the unbalanced dq coordinate current command vector I _dqbr by the unbalanced dq coordinate converter 221, and the dq coordinate current deviation calculator 224 does not. The deviation between the balanced dq coordinate current command vector I _dqbr and the dq coordinate current vector I _dq is output to the invalid current controller 225 and the effective current controller 226, and the invalid power compensation is performed by the invalid current controller 225 and the effective current controller 226. The ineffective power compensation device 2 is controlled so that each component of the xyb coordinate system of the output current i _αβ of the device 2 follows each component of the unbalance compensation current command vector i _{xybr (unbalance compensation current command).} Therefore, the unbalanced dq coordinate converter 221 and the dq coordinate converter 223, the dq coordinate current deviation calculator 224, the reactive current controller 225 and the reactive current controller 226 are the xyb coordinates _{of the output current i αβ of the reactive power compensator 2.} The unbalanced current controller 232 that controls the reactive power compensating device 2 so that each component of the system follows each component of the unbalanced compensating current command vector i _{xybr (unbalanced compensating current command) constitutes.}

Focusing on the suppression of the harmonic voltage, the dq coordinate current controller 22 proportionalizes the deviation between each component of the output of the nth harmonic dq coordinate current converter 215 and each component of the output of the current detector 12. It is integrated and amplified and output. However, in the dq coordinate system that rotates in the forward direction at the frequency of the power system 1, the gain corresponding to the integration term is designed to be the gain corresponding to the dq coordinate system even if the proportional integral amplification is performed. It causes a delay. Therefore, the harmonic current controller 21 integrates and amplifies the integral gain with an appropriate integral gain in the corresponding xyn coordinate system.

_{That is, the output current of the static} power compensator 2 can be quickly matched with the nth harmonic compensation current command vector i xynr by performing proportional amplification in the dq coordinate system and integral amplification in the xyn coordinate system.

Referring to FIG. 1 again, the dq coordinate voltage command calculator 23 (voltage command calculator) is the sum of the components of _{the reactive current command v qfbr output from the reactive current controller 225 shown in the equation (9).} The total q-axis voltage command v _qr is output to the reactive power compensator 2. Further, the dq coordinate voltage command calculator 23 outputs the total d-axis voltage command v _{dr , which is the sum of each component of the effective voltage command v dfbr} output from the active current controller 226, to the static power compensator 2. In equation (9), v _q5r is the q-axis component of the fifth harmonic dq coordinate voltage command vector v _dq5r. v _q7r is the q-axis component of the 7th harmonic dq coordinate voltage command vector v _dq7r. v _q11r is the q-axis component of the 11th harmonic dq coordinate voltage command vector v _dq11r. v _q13r is the q-axis component of the 13th harmonic dq coordinate voltage command vector v _dq13r. v _d5r is the d-axis component of the fifth harmonic dq coordinate voltage command vector v _dq5r. v _d7r is the d-axis component of the 7th harmonic dq coordinate voltage command vector v _dq7r. v _d11r is the d-axis component of the 11th harmonic dq coordinate voltage command vector v _dq11r. v _d13r is the d-axis component of the 13th harmonic dq coordinate voltage command vector v _dq13r.

As described above, according to the control device 10 of the static power compensator 2 according to the present embodiment, various controls such as voltage control, imbalance compensation control, and harmonic suppression control can be realized.

(Second embodiment)
FIG. 14 is a diagram showing an example of the configuration of the control device 10A of the static power compensator 2 according to the second embodiment of the present invention. In FIG. 14, the same components as those in FIG. 1 are designated by the same reference numerals, and the description thereof will be omitted.

In FIG. 14, the ineffective power compensator 2 includes a three-phase power converter 3, a converter side reactor 4, a filter capacitor 5, a transformer 6, a converter current detector 7, and a filter voltage detector 8. An example with and is shown.

The three-phase power converter 3 outputs a three-phase voltage according to the command values (total q-axis voltage command v _qr and total d-axis voltage command v _{dr) output from the dq coordinate voltage command calculator 23.}

One end of the converter side reactor 4 is connected to the output of the three-phase power converter 3. The converter side reactor 4 is provided corresponding to each of the three-phase outputs of the three-phase power converter 3.

The filter capacitor 5 is provided corresponding to each of the three-phase outputs of the three-phase power converter 3, and one end thereof is connected to the other end of the reactor 4 on the converter side. Further, the other ends of the filter capacitors 5 are connected to each other.

One end of the transformer 6 is connected to one end of the filter capacitor 5, and the other end is connected to the power system 1. The transformer 6 may be a reactor (system side reactor).

_{The converter current detector 7 detects the current i αβ} output from the three-phase power converter 3 and flows through the reactor 4 on the converter side, and the detection results are described later in the harmonic current controller 21A and the dq coordinate current controller 22A. Output to.

The filter voltage detector 8 detects the voltage of the filter capacitor 5 (filter voltage V _cαβ ) and outputs the detection result to the harmonic current controller 21A and the dq coordinate current controller 22A.

It is necessary to remove the component of the switching frequency times included in the output voltage of the three-phase power converter 3 composed of a three-phase inverter or the like. Therefore, in the static power compensator 2 shown in FIG. 14, a filter capacitor 5 is provided. However, when the filter capacitor 5 is included and the converter current detector 7 detects the current i _{αβ flowing through the converter side reactor 4, the output current i αβ} of the ineffective power compensator 2 is not controlled, but three. The output current of the phase power converter 3 will be controlled. Therefore, it is necessary to correct each current command output from the voltage magnitude controller 14, the unbalanced voltage controller 18, and the harmonic voltage controller 20 with the estimated value of the current of the filter capacitor 5 in the corresponding rotating coordinate system. There is. The control device 10A of the static power compensator 2 according to the present embodiment corrects each of the above-mentioned current commands.

In the control device 10A shown in FIG. 14, the harmonic current controller 21 was changed to the harmonic current controller 21A and the dq coordinate current controller 22 was changed to the dq coordinate current as compared with the control device 10 shown in FIG. It is different from the point changed to the controller 22A.

FIG. 15 is a diagram showing an example of the configuration of the harmonic current controller 21A. The harmonic current controller 21A includes the configuration shown in FIG. 15 corresponding to the harmonics of each order. In FIG. 15, the same reference numerals are given to the same configurations as those in FIG. 12, and the description thereof will be omitted.

The harmonic current controller 21A shown in FIG. 15 has a filter nth harmonic voltage detector 216 and a condenser nth harmonic current estimator 217 (condenser current) as compared with the harmonic current controller 21 shown in FIG. An estimator) and an nth harmonic current command corrector 218 are additionally provided.

The filter nth harmonic voltage detector 216 converts the filter voltage V _cαβ detected by the filter voltage detector 8 into rotational coordinates at n times the voltage phase θ (nθ), and calculates the moving average in a half cycle of the power system 1. By calculating, the filter nth harmonic voltage vector V _cxyn (capacitor voltage) is acquired. The filter nth harmonic voltage detector 216 outputs the acquired filter nth harmonic voltage vector V _cxyn to the capacitor nth harmonic current estimator 217.

The capacitor nth harmonic current estimator 217 uses the filter nth harmonic voltage vector V _cxyn output from the filter nth harmonic voltage detector 216 to obtain the filter capacitor 5 based on the following equation (10). The nth harmonic capacitor current vector i _cxyn (xn-axis component i _cxn and yn-axis component i _cyn ), which is the flowing current, is estimated. In equation (10), ω is the angular frequency of the power system 1, and C _f is the capacitance of the filter capacitor 5.

The capacitor nth harmonic current estimator 217 outputs the estimated nth harmonic capacitor current vector i _cxyn to the nth harmonic current command corrector 218.

The nth harmonic current command corrector 218 (harmonic current command corrector) transmits the nth harmonic compensation current command vector i _xynr to the nth harmonic capacitor current output from the nth harmonic current estimator 217. Using the vector i _cxyn , correction is performed based on the following equation (11). The corrected nth harmonic compensation current command vector _i'xynr is a reactor current command that indicates a reactor current that is a current flowing through the converter side reactor 4. n-th harmonic current command compensator 218 outputs the n-th harmonic compensation current command vector _i 'xynr (xn-axis component i' the _xnr and yn-axis component i _ynr) to the n-th harmonic current deviation calculator 212.

FIG. 16 is a diagram showing an example of the configuration of the dq coordinate current controller 22A. In FIG. 16, the same components as those in FIG. 13 are designated by the same reference numerals, and the description thereof will be omitted.

Compared with the dq coordinate current controller 22 shown in FIG. 13, the dq coordinate current controller 22A shown in FIG. 16 has a filter dq coordinate voltage detector 227, a capacitor dq coordinate current estimator 228, and a filter unbalanced voltage detector 229. , The point that the capacitor unbalanced current estimator 230 and the unbalanced current command estimator 231 were added, the point that the unbalanced dq coordinate converter 221 was changed to the unbalanced dq coordinate converter 221A, and the total current command calculator 222. This is different from the change to the total current command calculator 222A.

The filter dq coordinate voltage detector 227 converts the filter voltage V _cαβ detected by the filter voltage detector 8 into rotational coordinates in the negative voltage phase θ, and moves and averages the filter dq in a half cycle of the power system 1. Get the coordinate voltage vector V _cdq . The filter dq coordinate voltage detector 227 outputs the acquired filter dq coordinate voltage vector V _cdq to the capacitor dq coordinate current estimator 228.

The capacitor dq coordinate current estimator 228 uses the filter dq coordinate voltage vector V _{cdq output from the filter dq coordinate voltage detector 227, and the dq coordinate compensation current vector I cdq} (q axis) based on the following equation (12). Component i _cq and d-axis component i _cd ).

The capacitor dq coordinate current estimator 228 outputs the estimated dq coordinate compensation current vector I _cdq to the total current command calculator 222A.

The filter unbalanced voltage detector 229 converts the filter voltage V _cαβ detected by the filter voltage detector 8 into rotational coordinates with the voltage phase θ, and moves and averages the filter voltage V cαβ in a half cycle of the power system 1 to obtain a filter unbalanced voltage vector. Get V _cxyb . The filter unbalanced voltage detector 229 outputs the acquired filter unbalanced voltage vector V _cxyb to the capacitor unbalanced current estimator 230.

The capacitor unbalanced current estimator 230 uses the filter unbalanced voltage vector V _{cxyb output from the filter unbalanced voltage detector 229, and uses the unbalanced capacitor current vector I cxyb} (x-axis) based on the following equation (13). The component i _cxb and the y-axis component i _cyb ) are estimated.

The capacitor unbalanced current estimator 230 _{outputs the estimated unbalanced capacitor current vector I cxyb} to the unbalanced current command estimator 231.

The unbalanced current command estimator 231 uses _{each component of the unbalanced compensation current command vector i xybr} and each component of the unbalanced capacitor current vector I _cxyb output from the capacitor unbalanced current estimator 230 as follows. Based on the equation (14), the imbalance compensation current command vector _I'xybr is generated. The unbalanced current command estimator 231 outputs the generated unbalanced compensation current command vector _I'xybr (x-axis component _i'xbr and y-axis component _i'ybr ) to the unbalanced dq coordinate converter 221A.

The unbalanced dq coordinate converter 221A is an unbalanced _{dq coordinate system vector by converting the unbalanced compensation current command vector I'xybr} output from the unbalanced current command estimator 231 into rotational coordinates with the voltage phase θ. The dq coordinate current command vector I _dqbr is generated and output to the total current command calculator 222A.

As represented by the equation (15), the total current command calculator 222A adds the q-axis component of the current command of each input dq coordinate and the d-axis component of the _{dq coordinate compensation current vector I cdq, and sums them.} It is output to the dq coordinate current deviation calculator 224 as an invalid current command i _qr. Further, the total current command calculator 92 subtracts the q-axis component of the dq coordinate compensation current vector from the sum of the d-axis components of the current command of each input dq coordinate, and sets the total effective current command _{id r} to the dq coordinate current. Output to the deviation calculator 224.

As described above, according to the control device 10A of the static power compensator 2 according to the present embodiment, various controls such as voltage control, imbalance compensation control, and harmonic suppression control can be realized with higher accuracy.

(Third Embodiment)
FIG. 17 is a diagram showing an example of the configuration of the control device 10B of the static power compensator 2 according to the third embodiment of the present invention. In FIG. 17, the same reference numerals are given to the configurations similar to those in FIG. 14, and the description thereof will be omitted.

The control device 10B shown in FIG. 17 is different from the control device 10A shown in FIG. 14 in that the interconnection point voltage detector 11 is deleted and the voltage corrector 24 is added.

The voltage corrector 24 uses the filter voltage V _{cαβ detected by the filter voltage detector 8 and the invalid current command i qfr} , which is the output of the voltage magnitude controller 14, as the dq coordinate vector i _dqfr (d-axis component is 0). _{The unbalanced compensation current command vector i xybr} , which is the output of the unbalanced voltage controller 18, _{and the nth harmonic compensation current command vector i xynr} , which is the output of the harmonic voltage controller 20, are used. so as to correct the voltage drop and the transformer ratio N caused by the low-pressure side leakage inductance L ₁ of the transformer 6, based on the following equation (16), interconnection node voltage V _{'.alpha..beta} (alpha -axis component v' _alpha and β Estimate the axis component _v'β). That is, the second and subsequent terms of the equation 16 are the voltage drops due to _{the combined leakage inductance L 1} on the high voltage side and the low voltage side of the transformer 6 when viewed from the high voltage side.

The voltage corrector 24 outputs the estimated interconnection point voltage _V'αβ to the voltage magnitude detector 13, the dq coordinate voltage converter 15, the unbalanced voltage detector 17, and the harmonic voltage detector 19.

In the present embodiment, various controls such as voltage control, imbalance compensation control, and harmonic suppression control can be realized without providing the interconnection point voltage detector 11.

Although the present invention has been described with reference to the drawings and embodiments, it should be noted that those skilled in the art can easily make various modifications or modifications based on the present disclosure. Therefore, it should be noted that these modifications or modifications are within the scope of the present invention. For example, the functions included in each block and the like can be rearranged so as not to be logically inconsistent, and a plurality of blocks can be combined or divided into one.

1 Power system 2 Invalid power compensator 3 Three-phase power converter 4 Converter side reactor 5 Filter capacitor 6 Transformer 7 Converter Current detector 8 Filter voltage detector 10 Controller 11 Interconnection point voltage detector 12 Current detector 13 Voltage magnitude detector 14 Voltage magnitude controller 15 dq coordinate voltage converter 16 Phase adjuster 17 Unbalanced voltage detector 18 Unbalanced voltage controller 19 Harmonic voltage detector 20 Harmonic voltage controller 21,21A Harmonic Wave current controller 22,22A dq coordinate current controller 23 dq coordinate voltage command calculator 24 voltage corrector 141 voltage deviation calculator 142 voltage dead zone detector 143 error calculator 144 current dead band detector 145 filter output switcher 146 primary delay Filter 147 Subtractor 148 Error amplifier 181 Unbalanced compensation current command generator 182 Unbalanced voltage vector generator with dead zone 183 Unbalanced voltage magnitude calculator 184 Unbalanced voltage Dead zone detector 185 Unbalanced compensation current command generator 201 nth order Harmonic suppression current command generator 202 Nth harmonic voltage vector generator with dead band 203 nth harmonic voltage magnitude calculator 204 nth harmonic voltage dead band detector 205 nth harmonic suppression current command generator 211 nth order Harmonic current detector 212 nth harmonic current deviation calculator 213 xyn coordinate system integrator 214 nth harmonic dq coordinate voltage converter 215 nth harmonic dq coordinate current converter 216 filter nth harmonic voltage detector 217 Condenser nth harmonic voltage estimator 218 nth harmonic current command corrector 221,221A Unbalanced dq coordinate converter 222, 222A Total current command calculator 223 dq coordinate current deviation calculator 224 dq coordinate converter 225 Invalid current control 226 Effective current controller 227 Filter dq coordinate voltage detector 228 Condenser dq coordinate voltage detector 229 Filter unbalanced voltage detector 230 Condenser unbalanced current estimator 231 Unbalanced current command estimator 301 Gain amplifier 302, 302a, 302b- 1,302b-2,302c First-order lag filter 303, 303a, 303c Adder 304, 304a, 304b, 304c Output switcher 305 Multiplier 306 Integrator

Claims (9)

A control device that controls the static VAR compensator connected to the power system.
A voltage magnitude controller that outputs a reactive current command that indicates the reactive current output by the reactive power compensator, and
The reactive current component of the output current of the reactive power compensator, which is orthogonal to the direction of the interconnection point voltage which is the voltage at the connection point between the power system and the reactive power compensator, follows the reactive current command. A reactive current controller that controls the reactive power compensator is provided.
The voltage magnitude controller is
A voltage deviation calculator that calculates the deviation between the voltage command of the interconnection point voltage and the magnitude of the interconnection point voltage, and
When the deviation is equal to or more than the upper limit value of the predetermined dead zone, a value obtained by subtracting the upper limit value from the deviation is output, and when the deviation is equal to or less than the lower limit value of the dead zone, the lower limit is obtained from the deviation. A voltage dead zone detector that outputs a value obtained by subtracting a value and outputs 0 when the deviation is larger than the lower limit value and smaller than the upper limit value.
When the output of the voltage dead zone detector is not 0, the output of the voltage dead zone detector is proportionally integrated and amplified and output as the reactive current command. When the output of the voltage dead zone detector is 0, the output is A control device including an error amplifier that brings the reactive current command close to 0 with a predetermined time constant. A control device that controls the static VAR compensator connected to the power system.
A voltage magnitude controller that outputs a reactive current command that indicates the reactive current output by the reactive power compensator, and
The reactive current component of the output current of the reactive power compensator, which is orthogonal to the direction of the interconnection point voltage which is the voltage at the connection point between the power system and the reactive power compensator, follows the reactive current command. A reactive current controller that controls the reactive power compensator is provided.
The voltage magnitude controller is
A primary lag filter that outputs a voltage command that has undergone primary lag processing for the input voltage command,
An error amplifier that proportionally integrates and amplifies the deviation between the voltage command output from the primary delay filter and the magnitude of the interconnection point voltage and outputs it as the reactive current command.
When the reactive current command output by the error amplifier is equal to or greater than the upper limit of the dead band of the reactive current, the lower limit voltage command is input to the primary delay filter and the reactive current command output by the error amplifier is input. However, when it is equal to or less than the lower limit value of the dead zone, the upper limit voltage command is input to the first-order lag filter, and the reactive current command output by the error amplifier is larger than the lower limit value and smaller than the upper limit value. In the case of a control device, the control device includes a filter output switch that inputs the output of the primary lag filter to the primary lag filter. A control device that controls the static VAR compensator connected to the power system.
The interconnection point voltage, which is the voltage at the connection point between the power system and the ineffective power compensator, is subjected to rotational coordinate conversion with a negative voltage phase, and the orthogonal d-axis that rotates in the forward direction at the frequency of the power system. A dq coordinate voltage converter that outputs a voltage vector of the components of the dq coordinate system consisting of the q axis,
A phase adjuster that outputs the voltage phase such that the average value of the q-axis components of the voltage vector becomes 0 in a half cycle of the frequency of the power system.
The voltage vector of a component of the xyb coordinate system composed of orthogonal xb axes and yb axes that rotate in opposite directions at the frequency of the power system, which is obtained by converting the interconnection point voltage into rotational coordinates with the voltage phase. An unbalanced voltage detector that outputs an unbalanced voltage vector, which is the average value in a half cycle,
An unbalanced compensation current command generator that proportionally integrates and amplifies each component of the xyb coordinate system of the unbalanced voltage vector and outputs it as an unbalanced compensation current command.
Each component of the xyb coordinate system of the output current of the static VAR compensator is provided with an unbalanced current controller that controls the static VAR compensator so that each component of the xyb coordinate system follows each component of the unbalanced compensation current command. A control device characterized by. A control device that controls the static VAR compensator connected to the power system.
The interconnection point voltage, which is the voltage at the connection point between the power system and the ineffective power compensator, is subjected to rotational coordinate conversion with a negative voltage phase, and the orthogonal d-axis that rotates in the forward direction at the frequency of the power system. A dq coordinate voltage converter that outputs a voltage vector of the components of the dq coordinate system consisting of the q axis,
A phase adjuster that outputs the voltage phase such that the average value of the q-axis components of the voltage vector becomes 0 in a half cycle of the frequency of the power system.
The voltage vector of a component of the xyb coordinate system composed of orthogonal xb axes and yb axes that rotate in opposite directions at the frequency of the power system, which is obtained by converting the interconnection point voltage into rotational coordinates with the voltage phase. An unbalanced voltage detector that outputs an unbalanced voltage vector, which is the average value in a half cycle,
When the magnitude of the unbalanced voltage vector is less than the width of the dead zone of the unbalanced voltage, an output voltage vector having a magnitude of 0 is output, and the magnitude of the unbalanced voltage vector is the magnitude of the dead zone. When the width is greater than or equal to the width, an unbalanced voltage dead zone detector that outputs a vector having the width of the unbalanced voltage dead zone in the same direction as the unbalanced voltage vector as an output voltage vector.
When the magnitude of the output voltage vector is not 0, each component of the output voltage vector is proportionally integrated and amplified and output as an imbalance compensation current command, and when the magnitude of the output voltage vector is 0, it is output. An unbalanced compensation current command generator that outputs an unbalanced compensation current command so that the unbalanced compensation current command approaches 0 with a predetermined time constant.
Each component of the xyb coordinate system of the output current of the static VAR compensator is provided with an unbalanced current controller that controls the static VAR compensator so that each component of the xyb coordinate system follows each component of the unbalanced compensation current command. A control device characterized by. A control device that controls the static VAR compensator connected to the power system.
The interconnection point voltage, which is the voltage at the connection point between the power system and the ineffective power compensator, is subjected to rotational coordinate conversion with a negative voltage phase, and the orthogonal d-axis that rotates in the forward direction at the frequency of the power system. A dq coordinate voltage converter that outputs a voltage vector of the components of the dq coordinate system consisting of the q axis,
A phase adjuster that outputs the voltage phase such that the average value of the q-axis components of the voltage vector becomes 0 in a half cycle of the frequency of the power system.
With the orthogonal xn axis rotating at a frequency n times the frequency of the power system obtained by rotating the interconnection point voltage at an angle n (n is a multiple of 6 ± 1) times the voltage phase. A harmonic voltage detector that outputs the nth harmonic voltage vector, which is the average value in the half cycle of the voltage vector of the component of the xyn coordinate system including the yn axis,
A harmonic suppression current command generator that proportionally integrates and amplifies each component of the nth harmonic voltage vector and outputs it as an nth harmonic suppression current command.
A harmonic current controller that controls the static VAR compensator so that each component of the xyn coordinate system of the output current of the static VAR compensator follows each component of the nth harmonic suppression current command. A control device characterized by being provided. A control device that controls the static VAR compensator connected to the power system.
The interconnection point voltage, which is the voltage at the connection point between the power system and the ineffective power compensator, is subjected to rotational coordinate conversion with a negative voltage phase, and the orthogonal d-axis that rotates in the forward direction at the frequency of the power system. A dq coordinate voltage converter that outputs a voltage vector of the components of the dq coordinate system consisting of the q axis,
A phase adjuster that outputs the voltage phase such that the average value of the q-axis components of the voltage vector becomes 0 in a half cycle of the frequency of the power system.
With the orthogonal xn axis rotating at a frequency n times the frequency of the power system obtained by rotating the interconnection point voltage at an angle n (n is a multiple of 6 ± 1) times the voltage phase. A harmonic voltage detector that outputs the nth harmonic voltage vector, which is the average value in the half cycle of the voltage vector of the component of the xyn coordinate system including the yn axis,
When the magnitude of the nth harmonic voltage vector is less than the width of the dead zone of the nth harmonic voltage, an output voltage vector having a magnitude of 0 is generated, and the magnitude of the nth harmonic voltage vector is large. When is equal to or greater than the width of the dead zone of the nth harmonic voltage, a vector having a predetermined dead zone magnitude of the nth harmonic voltage in the same direction as the nth harmonic voltage vector is used as the nth harmonic voltage vector. An nth harmonic voltage vector generator with a dead band that is subtracted from the second harmonic voltage vector and output as an output voltage vector,
When the magnitude of the output voltage vector is not 0, each component of the output voltage vector is proportionally integrated and amplified and output as an nth harmonic suppression current command, and the magnitude of the output voltage vector is 0. The nth harmonic suppression current command generator that outputs the nth harmonic suppression current command such that the nth harmonic suppression current command approaches 0 with a predetermined time constant is used.
A harmonic current controller that controls the static VAR compensator so that each component of the xyn coordinate system of the output current of the static VAR compensator follows each component of the nth harmonic suppression current command. A control device characterized by being provided. In the control device according to claim 5 or 6.
The harmonic current controller
An nth harmonic current detector that outputs an nth harmonic current vector that is an average value in the half cycle of the current vector of each component of the xyn coordinate system of the output current of the static power compensator.
An xyn coordinate system integrator that proportionally integrates and amplifies the deviation between each component of the nth harmonic suppression current command and each component of the nth harmonic current vector and outputs it.
An nth harmonic dq coordinate current converter that converts the nth harmonic suppression current command into components of the dq coordinate system and outputs the nth harmonic suppression current command.
The nth harmonic dq coordinate voltage converter that converts the output of the xyn coordinate system integrator into the components of the dq coordinate system and outputs the integrator is provided.
A current detector that detects and outputs each component of the dq coordinate system of the output current of the static power compensator, and
A dq coordinate current controller that proportionally integrates and amplifies the deviation between each component of the output of the nth harmonic dq coordinate current converter and each component of the output of the current detector and outputs the output.
A voltage command calculator that outputs the sum of the output of the harmonic current controller and the output of the dq coordinate current controller as a command value of the output voltage of the static VAR compensator is further provided. Control device. In the control device according to claim 5 or 6.
The static power compensator is
A three-phase power converter that outputs a voltage according to the command value,
The reactor on the converter side, one end of which is connected to the output of the three-phase power converter,
A connected filter capacitor connected to the other end of the converter side reactor,
A system-side reactor or transformer, one end connected to one end of the filter capacitor and the other end connected to the power system.
The harmonic current controller
A filter voltage detector that detects the filter voltage, which is the voltage of the filter capacitor, and
A capacitor current estimator that estimates the current flowing through the filter capacitor based on the capacitor voltage, and
A harmonic current command corrector that corrects the nth harmonic suppression current command with the current to generate and output a reactor current command that indicates a reactor current that is a current flowing through the converter-side reactor.
An nth harmonic current detector that outputs an nth harmonic current vector that is an average value in the half cycle of the current vector of each component of the xyn coordinate system of the reactor current.
An xyn coordinate system integrator that proportionally integrates and amplifies the deviation between each component of the nth harmonic suppression current command and each component of the nth harmonic current vector and outputs it.
An nth harmonic dq coordinate current converter that converts the nth harmonic suppression current command into components of the dq coordinate system and outputs the nth harmonic suppression current command.
The nth harmonic dq coordinate voltage converter that converts the output of the xyn coordinate system integrator into the components of the dq coordinate system and outputs the integrator is provided.
A current detector that detects and outputs each component of the dq coordinate system of the output current of the static power compensator, and
A dq coordinate current controller that proportionally integrates and amplifies the deviation between each component of the output of the nth harmonic dq coordinate current converter and each component of the output of the current detector and outputs the output.
A control including a voltage command calculator that outputs the sum of the output of the harmonic current controller and the output of the dq coordinate current controller as a command value of the output voltage of the static power compensator. apparatus. In the control device according to any one of claims 1 to 7.
The static power compensator is
A three-phase power converter that outputs a voltage according to the command value,
The reactor on the converter side, one end of which is connected to the output of the three-phase power converter,
A connected filter capacitor connected to the other end of the converter side reactor,
A system-side reactor or transformer, one end connected to one end of the filter capacitor and the other end connected to the power system.
A control device further comprising a voltage corrector that corrects a voltage drop due to the transformer from the magnitude of the filter voltage, which is the voltage of the filter capacitor, and outputs the voltage as the interconnection point voltage.

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