JP2022048702A - Power system, control device, power compensation unit, and control method - Google Patents

Abstract

To provide a technique capable of controlling a power factor of a power system side to be constant even when effective power fluctuates.SOLUTION: A power system includes: a generator 300 that is connected to a power system 500 and outputs effective power and reactive power; an SVC 200 that is connected to the power system 500 and outputs reactive power; a controller 100 for controlling the SVC 200; a first detector 600 for detecting an effective power value P1 output from the generator 300 and a reactive power value Q1 output from the generator 300; and a second detector 700 for detecting an effective power value P2 output from the power system 500 and a reactive power value Q2 output from the power system 500. The control device 100 calculates a first quantity based on a difference between a value based on the effective power value P1 and the reactive power value Q1 and calculates a second quantity based on a difference between a value based on the effective power value P2 and the reactive power value Q2 to control a reactive power value Q3 by adding the first quantity and the second quantity.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to power systems, controls, power compensation units, and control methods.

In general, a generator outputs active power as well as reactive power. Active power is the power consumed by the load. On the other hand, reactive power is power that is not consumed by the load. In addition, fluctuations in the reactive power may cause voltage fluctuations and the like. In view of this point, a static power compensator that outputs static power has been proposed in order to suppress voltage fluctuations. Patent Document 1 discloses a power system including a static power compensator connected to a power system, a control device for controlling the static power compensation device, and a generator connected to the power system. ..

Japanese Unexamined Patent Publication No. 2004-104865

In an electric power system that outputs electric power to an electric power system, control to keep the power factor on the electric power system side constant is desired. The power factor is a value determined by active power and active power. In this control, it is conceivable to set a target value of the reactive power output from the reactive power compensator and control the reactive power to the target value to keep the power factor constant.

For example, when the invention described in Patent Document 1 is configured to execute the control for keeping the power factor constant as described above, it is based on the active power from the generator and the reactive power from the generator. , A configuration is conceivable to control the reactive power output from the reactive power compensator. Here, when the active power output from the generator changes, it is necessary to keep the power factor on the power system side constant. However, in this configuration, when the active power output from the generator changes, the value of the active power in the power system from the reactive power compensator cannot reach the target value, and as a result, the power system cannot be reached. There was a problem that the power factor on the side could not be controlled appropriately and constantly.

The present disclosure has been made to solve the above-mentioned problems, and the purpose in a certain aspect is to control the power factor on the power system side to be constant even when the active power fluctuates. It is to provide the technology that can be done.

A power system according to certain aspects of the present disclosure comprises a generator, an ineffective power compensator, a control device, a first detector, and a second detector. The generator is connected to the power system and outputs active power and reactive power. The static power compensator is connected to the power system and outputs static power. The control device controls the static VAR compensator. The first detector detects the active power value output from the generator and the invalid power value output from the generator. The second detector detects an active power value output to the power system and an ineffective power value output to the power system. The control device includes a first calculation unit, a second calculation unit, and a control unit. The first calculation unit calculates the first quantity based on the difference between the value based on the active power value detected by the first detector and the inactive power value detected by the first detector. The second calculation unit determines the difference between the value based on the active power value detected by the second detector and the active power value detected by the second detector, or the active power value detected by the first detector. The second quantity is calculated based on the difference between the value based on the value and the reactive power value detected by the second detector. The control unit controls the static power value output from the static power compensator by adding the first quantity and the second quantity.

According to the present disclosure, the first quantity based on the difference between the active power output from the generator and the ineffective power output from the generator, and the active power output to the power system and the ineffective power output to the power system. By adding the second quantity based on the difference between the above and the second quantity, the ineffective power value of the ineffective power compensator is controlled. Further, since the active power output to the power system and the active power output from the generator are substantially the same, the second amount is output to the active power output from the generator and the power system. It may be a value based on the difference from the dead power. As described above, according to the present disclosure, the static power value of the static power compensator is controlled by the added value of the first quantity and the second quantity. Therefore, even when the active power output from the generator changes, the value of the reactive power in the power system can reach the target value, and as a result, the power factor can be controlled to be constant.

The above and other objects, features, aspects and advantages of the invention will become apparent from the following detailed description of the invention as understood in connection with the accompanying drawings.

It is a configuration example of the electric power system of this embodiment. It is a block diagram which shows the hardware composition of a control device. It is a figure for demonstrating θ. It is a functional block diagram of a control device. It is a figure which shows an example of the waveform which shows the electric power value and the like output from each component part of the 1st calculation part. It is a figure which shows an example of the waveform such as electric power output from each component part of the 2nd calculation part. It is a figure which shows an example of the waveform of the reactive power value Q3 shown by the command signal generated by the generation part of a control part. It is a flowchart which shows an example of the processing of a control device. It is a block diagram of the control device of 2nd Embodiment.

The electric power system according to the embodiment based on the present invention will be described below with reference to the drawings. In addition, the same reference number may be assigned to the same parts and equivalent parts, and duplicate explanations may not be repeated. In addition, it is planned from the beginning to use at least a part of the configurations in each embodiment in appropriate combinations. In the following, the static var compensator (Static Var Compensator) will also be referred to as "SVC".

<First Embodiment>
[Power system configuration]
FIG. 1 is a configuration example of the power system 1000 of the present embodiment. The power system 1000 includes a static power compensation unit 250, a generator 300, a three-winding transformer 400, a first detector 600, and a second detector 700. The static power compensation unit 250 includes an SVC 200 and a control device 100 that controls the SVC 200. The generator 300 includes a control unit 302. Further, the SVC 200 and the generator 300 are connected to the power system 500 via the three-winding transformer 400.

The generator 300 uses natural energy such as solar power generation and wind power generation to generate electric power. The generator is typically an alternator. Active power and reactive power are output from the generator 300. Further, the value of the active power output from the generator 300 is referred to as "active power value P1", and the value of the active power output from the generator 300 is referred to as "reactive power value Q1". The active power and the reactive power output from the generator 300 are output to the load (not shown) of the power system 500 via the three-winding transformer 400. This load is driven on the basis of active power.

Further, the control unit 302 of the generator 300 controls the invalid power value Q1. For example, even when the active power value P1 fluctuates, the reactive power value Q1 is controlled so that the reactive power value Q1 becomes a value corresponding to the fluctuation value of the active power value P1. The method of controlling the control unit 302 may be another method. Further, the generator 300 may not have the control unit 302. That is, the generator 300 may not control the invalid power value Q1.

As will be described later, the SVC 200 outputs an reactive power for controlling the power factor to be constant (compensates for the reactive power). The value of the reactive power output from the SVC200 is referred to as "reactive power value Q3". The reactive power output from the SVC 200 is output to a load (not shown) of the power system 500 via the three-winding transformer 400. Further, the control device 100 controls the invalid power value Q3 output from the SVC 200.

The three-winding transformer 400 changes the voltage from the generator 300 to a predetermined voltage. Further, the three-winding transformer 400 receives the active power and the reactive power output from the generator 300 and the reactive power output from the SVC 200. The three-winding transformer 400 outputs the active power output from the generator 300 to the power system 500. Further, the three-winding transformer 400 adds the ineffective power output from the generator 300 and the ineffective power output from the SVC 200 and outputs it to the power system 500.

The first detector 600 is installed between the three-winding transformer 400 and the generator 300. The first detector 600 detects the active power value P1 and the active power value Q1 from the generator 300. The first detector 600 may be divided into a detection unit that detects the active power value P1 and a detection unit that detects the invalid power value Q1. The first detector 600 outputs the active power value P1 and the active power value Q1 to the control device 100.

The second detector 700 is installed between the three-winding transformer 400 and the power system 500. The second detector 700 detects the active power value P2 and the reactive power value Q2 output from the three-winding transformer 400. The active power value P2 and the active power value Q2 are also power values output to the power system 500. The second detector 700 may be divided into a detection unit that detects the active power value P2 and a detection unit that detects the invalid power value Q2. The second detector 700 outputs the active power value P2 and the active power value Q2 to the control device 100.

The control device 100 determines the reactive power value Q3 so that the "power factor on the power system 500 side" described later becomes the target power factor. In the present embodiment, the control device 100 determines the active power value Q3 based on the active power value P1, the active power value Q1, the active power value P2, and the active power value Q2. The control device 100 controls the SVC 200 so that the reactive power of the determined reactive power value Q3 is output from the SVC 200.

[Hardware configuration of controller]
FIG. 2 is a block diagram showing a hardware configuration of the control device 100. The control device 100 has a controller 150. The controller 150 has a CPU (Central Processing Unit) 160, a ROM (Read Only Memory) 162, a RAM (Random Access Memory) 164, an HDD (Hard Disk Drive) 166, and a communication I / F (communication I / F) as main components. Interface) 168. The components are interconnected by a data bus.

Under the control of the CPU 160, the communication I / F 168 can output a command signal to the SVC 200. The command signal includes an invalid power value Q3 output from the SVC200.

The ROM 162 stores a program executed by the CPU 160. The RAM 164 can temporarily store the data generated by executing the program in the CPU 160 and the data input via the communication I / F 168. The RAM 164 can function as a temporary data memory used as a work area. HDD 166 is a non-volatile storage device. Further, instead of the HDD 166, a semiconductor storage device such as a flash memory may be adopted.

Further, the program stored in the ROM 162 may be stored in a storage medium and distributed as a program product. Alternatively, the program may be provided by an information provider as a program product that can be downloaded via the so-called Internet or the like. The control device 100 reads a program provided by a storage medium, the Internet, or the like. The control device 100 stores the read program in a predetermined storage area (for example, ROM 162). The CPU 160 executes the above-mentioned display process by executing the stored program.

The storage medium is not limited to DVD-ROM (Digital Versatile Disk Read Only Memory), CD-ROM (compact disc read-only memory), FD (Flexible Disk), and hard disk, but also magnetic tape, cassette tape, and optical disc (MO (Magnetic)). Semiconductors such as optical discs) / MDs (Mini Discs) / DVDs (Digital Versatile Discs), optical cards, mask ROMs, EPROMs (Electronically Programmable Read-Only Memory), EEPROMs (Electronically Erasable Programmable Read-Only Memory), flash ROMs, etc. It may be a medium such as a memory that carries a fixed program. The recording medium is a non-temporary medium in which a computer can read a program or the like.

[About target power factor]
In the control device 100 of the present embodiment, the power factor determined by the active power output to the power system 500 and the ineffective power output to the power system 500 (hereinafter, also referred to as “power factor on the power system 500 side”) is determined. The SVC200 is made to output the reactive power that becomes the target power factor. Further, as shown in FIG. 5 and the like described later, the active power value P1 may fluctuate. The control device 100 controls the SVC 200 so that the power factor on the power system 500 side becomes the target power factor even if the active power value P1 fluctuates. Further, the reactive power value when the target power factor is reached is also referred to as "target value of reactive power".

FIG. 3 is a diagram for explaining an example of the target power factor cos θ. In FIG. 3, a right triangle with the active power value P as the base and the active power value Q as the height is shown. The hypotenuse is the apparent power S. θ is an angle formed by the hypotenuse indicating the apparent power S and the base indicating the active power value P. Also, the target power factor is typically represented by cos θ. That is, the target power factor cos θ can be expressed by the following equation (1).

Target power factor cos θ = P / S = P / {(P ² + Q ² ) ^1/2 } (1)
This target power factor cos θ is a value predetermined by a designer or the like. Therefore, θ is also a predetermined value.

Further, the power factor cosφ1 determined by the active power and the reactive power output from the SVC 200 and the active power output from the generator 300 is expressed by the following equation (2) using P1, Q1 and Q3. be able to.

cos φ1 = P1 / {(P1 ² + (Q1 + Q3) ² ) ^1/2 } (2)
The power factor cosφ1 of the formula (2) is also referred to as “power factor on the generator 300 and SVC200 side”.

Further, the power factor cos φ2 on the power system 500 side can be expressed by the following equation (3) using P2 and Q2.

cos φ2 = P2 / {(P2 ² + Q2 ² ) ^1/2 } (3)
Further, when the change element described later does not exist, P1 = P2 and Q2 = Q1 + Q3. However, since the power system 1000 has a changing element that changes at least one of active power and reactive power, P1≈P2 actually becomes P1≈P2, and Q2≈Q1 + Q3. The changing element is, for example, the impedance included in the three-winding transformer 400 and the plurality of wirings included in the power system 1000. The plurality of wirings include wiring connecting the generator 300 and the first detector 600, wiring connecting the first detector 600 and the three-winding transformer 400, and the ineffective power compensation unit 250 and the three-winding transformer 400. Wiring to connect, including wiring to connect the three-winding transformer 400 and the second detector 700.

[Control device configuration]
FIG. 4 is a functional block diagram of the control device 100. The control device 100 includes a first calculation unit 110, a second calculation unit 120, and a control unit 130. The first calculation unit 110 includes a tan θ multiplication unit 111, a first subtraction unit 112, a first gain unit 114, and a filter unit 116. The second calculation unit 120 includes a tan θ multiplication unit 121, a second subtraction unit 122, a second gain unit 124, and a filter unit 116.

First, the first calculation unit 110 will be described. The tan θ multiplication unit 111 included in the first calculation unit 110 multiplies the active power value P1 by tan θ. Since θ is a predetermined value as described above, tan θ is also a predetermined value.

As shown in the example of FIG. 3, the value obtained by multiplying the active power value P1 by tan θ is the ineffective power value corresponding to the ineffective power. Since the reactive power value Q (P1 · tanθ) is the reactive power value Q corresponding to the target power factor cosθ, it is also referred to as the “first target value of the reactive power”.

The tanθ multiplication unit 111 outputs P1 · tanθ to the first subtraction unit 112. The first subtraction unit 112 calculates the difference between P1 · tan θ and the reactive power value Q1 detected by the first detector 600. In the example of FIG. 4, the first subtraction unit 112 performs a subtraction of P1 · tan θ−Q1. The first subtraction unit 112 outputs P1 · tan θ−Q1 to the first gain unit 114.

The first gain unit 114 calculates K1 · (P1 · tanθ −Q1) by multiplying P1 · tanθ−Q1 by the first gain K1. The first gain K1 is a predetermined value. The first gain unit 114 outputs K1 · (P1 · tanθ−Q1) to the filter section 116.

The filter unit 116 executes a filter process on K1 · (P1 · tanθ−Q1) which is an output from the first gain section 114. This filter processing is a processing for removing the high frequency component of K1 · (P1 · tanθ−Q1). The filter unit 116 is configured by, for example, a low-pass filter. This low-pass filter is, for example, a first-order lag element. Further, the low-pass filter may be a multi-order lag element (for example, a second-order lag element). By executing the filter processing for K1 · (P1 · tanθ−Q1), the high frequency noise of K1 · (P1 · tanθ−Q1) can be removed. The filter unit 116 outputs K1 · (P1 · tanθ−Q1) from which the high frequency component has been removed to the control unit 130. Further, K1 · (P1 · tanθ-Q1) from which the high frequency component has been removed becomes the "first amount" and "operation amount for setting the reactive power value output from the SVC200 to the first target value" of the present disclosure. handle. Further, the first calculation unit 110 executes feedforward control in order to set the reactive power value output from the SVC 200 to the first target value. As described above, since the first calculation unit 110 executes the feedforward control, even if the active power value P1 fluctuates, it can quickly respond to the fluctuation. The first amount is also referred to as a feed forward amount.

By the way, it is conceivable that the control device 100 outputs cosφ1 to the target power factor cosθ by outputting the reactive power that becomes the first target value (P1 · tanθ) to the SVC200. However, as described above, the power system 1000 includes a changing element that changes the power factor (for example, the impedance included in the three-winding transformer 400). Therefore, P1 ≠ P2 and Q2 ≠ Q1 + Q3, so cos φ1 ≠ cos φ2.

Therefore, when the active power from the generator 300 fluctuates, even if cosφ1 becomes the target power factor cosθ, a deviation between cosφ2 and the target power factor cosθ occurs. Therefore, in the present embodiment, the second calculation unit 120 performs feedback control for eliminating this deviation. As a result, even when the active power from the generator 300 fluctuates, the "power factor cos φ2 on the power system 500 side" can be controlled to the target power factor cos θ.

The active power value P2 from the second detector 700 is input to the tan θ multiplication unit 121 included in the second calculation unit 120. The tanθ multiplication unit 121 multiplies the active power value P2 by tanθ. This tan θ is the same as the tan θ used in the tan θ multiplication unit 111. Further, as shown in the example of FIG. 3, the value obtained by multiplying the active power value P2 by tan θ is the ineffective power value corresponding to the ineffective power. Since this reactive power value (P2 · tanθ) is the reactive power value Q corresponding to the target power factor cosθ, it is also referred to as “second target value of reactive power”.

The tanθ multiplication unit 121 outputs P2 · tanθ to the second subtraction unit 122. The second subtraction unit 122 calculates the second quantity, which is the difference between P2 · tan θ and the reactive power value Q2 detected by the second detector 700. In the example of FIG. 4, the second subtraction unit 122 performs a subtraction of P2 · tanθ−Q2. The second subtraction unit 122 outputs P2 · tan θ−Q2 to the second gain unit 124.

The second gain unit 124 calculates K2 · (P2 · tanθ−Q2) by multiplying P2 · tanθ−Q2 by the second gain K2. The second gain K2 is a predetermined value. The first gain K1 and the second gain K2 may be the same or different. The second gain unit 124 outputs K2 · (P2 · tanθ−Q2) to the integrating section 126.

The integration unit 126 performs integration processing on K2 · (P2 · tanθ−Q2) for a predetermined period Δt. This integration process is a process for eliminating the above-mentioned deviation. Further, K2 · (P2 · tanθ-Q2) on which the integration process is executed becomes the “second quantity” and “operation amount for setting the reactive power value output from the SVC200 to the second target value” of the present disclosure. handle. Further, the second calculation unit 120 executes feedback control in order to set the reactive power value Q3 output from the SVC 200 to the second target value. Therefore, the second quantity is also referred to as a feedback quantity. The integrating unit 126 transmits the second value (K2 · (P2 · tanθ−Q2) where the integration process has been performed) to the adding unit 132.

The addition unit 132 included in the control unit 130 adds the first value from the filter unit 116 and the second value from the integration unit 126. This added value is the value of the reactive power output from the SVC 200 (reactive power value Q3). The generation unit 134 generates a command signal indicating the reactive power value Q3, and outputs the command signal to the SVC 200. The SVC200 outputs the reactive power of the reactive power value Q3 included in this command signal.

FIG. 5 is a diagram showing an example of a waveform showing a power value input to the first calculation unit 110 and a waveform showing a power value output from each component of the first calculation unit 110. FIG. 6 is a diagram showing an example of a waveform of electric power output from each component of the second calculation unit 120. FIG. 7 is a diagram showing an example of the waveform of the reactive power value Q3 indicated by the command signal generated by the generation unit 134 of the control unit 130.

The horizontal axis of FIGS. 5 to 7 is time. Further, in FIG. 5A, since the waveform of the active power value P1 is shown, the vertical axis represents watts. 5 (B) to 5 (E), and FIGS. 6 and 7, show the waveform of the power corresponding to the reactive power, so that the vertical axis indicates a bar. Further, FIGS. 5 to 7 are schematic views showing waveforms, and the wattage value and the bar value in each drawing are different from the actual values.

It is assumed that the active power value P1 is fluctuated (increased) at the timing t1 shown in FIGS. 5 to 7. Next, the factors that cause the active power value P1 to fluctuate will be described. For example, a case where the generator 300 has a solar panel and power is generated by solar power generation by the solar panel will be described. In this case, when the amount of sunlight per unit area of the solar panel fluctuates, the active power value P1 increases. Further, for example, in the case where the generator 300 has a wind turbine and is a device that generates power by wind power generation, the active power value P1 fluctuates when the air volume hitting the wind turbine fluctuates.

5 (B) to 5 (E) show a power value output from the tan θ multiplication unit 111, a power value output from the first subtraction unit 112, and a power value output from the first gain unit 114, respectively. And the waveform of the power value output from the filter unit 116 is shown.

As shown in FIG. 5B, when the active power increases at the timing T1, the power value output from the tan θ multiplication unit 111, the power value output from the first subtraction unit 112, and the first gain unit. The power value output from 114 also increases. As described above, the filter unit 116 removes the high frequency component of the output value from the first gain unit 114. Therefore, the top of the waveform shown in FIG. 5 (D) has a rounded shape as shown in FIG. 5 (E).

Next, FIG. 6 will be described. As shown in FIG. 6A, the power values P2 and tanθ output from the tanθ multiplication unit 121 fluctuate at the timing T1. As described above, P1 · tan θ ≈ P2 · tan θ.

As shown in FIG. 6B, the power value P2 · tan θ−Q2 output from the second subtraction unit 122 increases at the timing T1 and then gradually decreases. As shown in FIG. 6C, the power value output from the second gain unit 124 is also the power value output from the second gain unit 124 as in FIG. 6B, K2 (P2 · tan θ-). Q2) increases at timing T1 and then gradually decreases.

As shown in FIG. 6D, the voltage value output from the integrating unit 126 increases so as to converge to P2 · tan θ, which is the target value of the reactive power.

FIG. 7 is a diagram showing an example of a voltage value output from the addition unit 132. As described above, the voltage value output from the addition unit 132 is the reactive power value Q3 output from the SVC 200. In the example of FIG. 7, the power value increases at a relatively large rate of increase from timing T1 to timing T2. The reason why the increase rate of the power value from the timing T1 to the timing T2 becomes large is that the first calculation unit 110 executes the feed forward control so that the invalid power value from the SVC 200 becomes the first target value. (See location α in FIG. 5 (E)).

Further, after the timing T2, the voltage value output from the addition unit 132 gradually approaches the target value (P2 · tan θ) based on the feedback control of the second calculation unit 120, and at the timing T3, the voltage value reaches the target value. To reach. The generation unit 134 generates a command signal for outputting the ineffective power of the ineffective power value Q3 output from the addition unit 132 from the SVC 200. Upon receiving the command signal, the SVC 200 outputs the reactive power having the reactive power value Q3 indicated by the command signal.

For example, in the invention described in Patent Document 1, when the control to keep the power factor constant (hereinafter, also referred to as “constant control”) is executed, the active power from the generator and the ineffective power from the generator are executed. A configuration is conceivable to control the ineffective power output from the ineffective power compensator based only on the basis. Here, as shown in the timing T1 of FIG. 5A, it is necessary to keep the power factor constant even when the active power output from the generator changes. However, in this configuration, when the active power output from the generator changes, the power is generated from the generator even if constant control is executed based on the active power from the generator and the invalid power from the generator. Since the above-mentioned change elements are included in the system, the value of the ineffective power in the power system from the ineffective power compensator cannot reach the target value. As a result, there is a problem that the power factor on the power system side cannot be controlled to the target power factor in this configuration.

Therefore, in the control device 100 of the present embodiment, based on "the difference between the value based on the active power value P1 output from the generator 300 and the value based on the invalid power value Q1 output from the generator 300". The sum of the calculated first amount and the second value calculated based on "the active power value P2 output to the power system 500 side and the invalid power value Q2 output to the power system 500 side", The invalid power value is Q3. Then, the control device 100 outputs the reactive power of the reactive power value Q3 from the SVC 200. In particular, the second quantity is a value detected by the second detector 700 arranged between the three-winding transformer 400 and the power system 500. Therefore, even if a change element is included from the generator 300 to the power system 500, the power factor on the power system 500 side can be controlled to the target power factor.

Further, it is conceivable that the control device 100 does not use the first quantity and calculates the reactive power value Q3 based on the second quantity. That is, this configuration does not use the active power value P1 and the active power value Q1 detected by the first detector 600. In this configuration, the cooperation between the generator 300 and the SVC200 is not guaranteed. The points of concern due to this configuration will be described below.

The reactive power value Q1 output from the generator 300 may vibrate or diverge due to various causes. The first cause is a cause that may occur due to interference between the control of the reactive power value Q1 by the control unit 302 and the control of the reactive power value Q3 by the control device 100. The second cause is, for example, a cause that can occur when the load for outputting the reactive power is arranged in the power system 1000 other than the SVC 200 and the generator 300. The third cause is a cause that can occur when a malfunction of the generator 300 occurs. Further, the reactive power value Q1 may vibrate or diverge due to a cause other than the first to third causes. In the following, vibration or divergence may be referred to as "vibration or the like". In the configuration in which the control device 100 calculates the reactive power value Q3 based on the second quantity without using the first quantity, the power system 500 is generated when the reactive power output from the generator 300 vibrates or the like. The power factor on the side cannot be the target power factor.

On the other hand, in the power system 1000 of the present embodiment, not only the second amount but also the first amount calculated by the first calculation unit 110 (active power value P1 output from the generator 300 and reactive power value Q1). The specified amount) is also used. Specifically, as shown in FIG. 4, the control device 100 calculates the reactive power value Q3 based on the value P1 · tan θ−Q1. Therefore, even if the power system 1000 vibrates the reactive power value Q1, the power system 1000 can calculate the reactive power value Q3 in which the vibration is eliminated, and as a result, the power factor on the power system 500 side is targeted. It can be a power factor.

Further, the tanθ multiplication unit 111 calculates P1 · tanθ by multiplying the active power value P1 detected by the first detector 600 by tanθ (coefficient). This P1 · tan θ is the first target value of the reactive power output from the SVC200. The first target value is a value close to the second target value. The first calculation unit 110 calculates an operation amount (first amount) for setting the reactive power value output from the SVC 200 to the first target value by executing the feedforward control. Therefore, as described in Timing T1 to Timing T2 in FIG. 7, even if the active power value P1 from the generator 300 fluctuates, it is possible to respond at high speed. If the response to the fluctuation of the active power value P1 is slow, it becomes slow to make the power factor the same as the power factor before the fluctuation of the active power value P1, and as a result, a problem occurs in the load of the power system 500. In some cases. In the present embodiment, since the response to the fluctuation of the active power value P1 can be made faster, it is possible to reduce the occurrence of such a problem.

Further, the second calculation unit 120 calculates an operation amount (second amount) for setting the reactive power value output from the SVC 200 to the second target value by executing the feedback control. Therefore, the reactive power value output from the SVC 200 can be controlled to the target value (P2 · tan θ) on the power system 500 side. Therefore, as described above, the power factor on the power system 500 side can be controlled with high accuracy and stability to the target power factor while realizing a high-speed response to the fluctuation of the active power value P1.

Further, the filter unit 116 executes a filter process on K1 · (P1 · tanθ−Q1) which is an output from the first gain section 114. This filter processing is a processing for removing the high frequency component of K1 · (P1 · tanθ−Q1). By this processing, high frequency noise of K1 · (P1 · tanθ−Q1) can be removed. Further, as described above, even if the vibration of the reactive power value Q1 occurs, the filter unit 116 can suppress the vibration of the reactive power value Q1.

Further, as shown in FIG. 1, the SVC 200 and the generator 300 are connected to the power system 500 via a three-winding transformer 400. Therefore, the voltage from the generator 300 can be converted into a predetermined voltage. Further, the impedance of the three-winding transformer 400 and the like are the above-mentioned change factors, and even if this change factor exists, the power factor on the power system 500 side can be controlled to the target power factor.

[Control device processing]
FIG. 8 is a flowchart showing an example of processing of the control device 100. The process of FIG. 8 is a process executed every fixed time (for example, 0.1 second) elapses. It should be noted that steps S4 to S10 show the processing of the first calculation unit 110, and steps S12 to S18 show the processing of the second calculation unit 120.

In step S2, the control device 100 acquires the active power value P1 and the active power value Q1 from the first detector 600, and acquires the active power value P2 and the active power value Q2 from the second detector 700.

In step S4, the tan θ multiplication unit 111 of the first calculation unit 110 multiplies the active power value P1 by tan θ. Next, in step S6, the first subtraction unit 112 calculates the difference (P1 · tan θ−Q1) between P1 · tan θ and the reactive power value Q1 detected by the first detector 600.

Next, in step S8, the first gain unit 114 calculates K1 · (P1 · tanθ−Q1) by multiplying P1 · tanθ−Q1 by the first gain K1. Next, in step S10, the filter unit 116 executes a filter process on K1 · (P1 · tanθ−Q1) which is an output from the first gain section 114.

Further, in step S12, the tanθ multiplication unit 121 of the second calculation unit 120 multiplies the active power value P2 by tanθ. Next, in step S14, the second subtraction unit 122 calculates the difference between P2 · tan θ and the reactive power value Q2 detected by the second detector 700. Next, in step S16, the second gain unit 124 calculates K2 · (P2 · tanθ−Q2) by multiplying P2 · tanθ−Q2 by the second gain K2. Next, in step S18, the integration unit 126 performs integration processing on K2 · (P2 · tanθ−Q2) for a predetermined period Δt.

Next, in step S20, the addition unit 132 included in the control unit 130 calculates the reactive power value Q3 by adding the output value from the filter unit 116 and the output value from the integration unit 126. This completes the process.

<Second Embodiment>
FIG. 9 is a block diagram of the control device 100A of the second embodiment. In the first embodiment, as shown in FIG. 4, the active power value P1 is input to the tan θ multiplication unit 111 of the first calculation unit 110, and the active power value P2 is the tan θ multiplication unit 121 of the second calculation unit 120. The configuration to be input to is explained. In the second embodiment, as shown in FIG. 9, the active power value P1 is input to the tan θ multiplication unit 111 of the first calculation unit 110 and the tan θ multiplication unit 121 of the second calculation unit 120. In the second embodiment, the active power value P2 is not used. The other processes are the same as those in the first embodiment.

Further, in the flowchart of the control device 100A of the second embodiment, "calculate P2 · tan θ" in S12 is replaced with "calculate P1 · tan θ".

As described above, the active power value P1 ≈ the active power value P2. Therefore, the control device 100A of the second embodiment is lower than the control device 100 of the first embodiment in the accuracy of controlling the power factor to be constant. However, since it is not necessary to use the active power value P2, there is no need for wiring to output the active power value P2 from the second detector 700 to the control device 100.

<Other embodiments>
(1) If the control device 100 is configured to control the SVC 200 by using the active power values P1 and P2 and the active power values Q1 and Q2, other control may be executed. For example, the first calculation unit 110 executes feedforward control using the active power value P2 and the active power value Q2, and the second calculation unit 120 feeds back using the active power value P1 and the active power value Q1. Control may be performed.

(2) In the present embodiment, the configuration in which the SVC 200 and the generator 300 are connected to the power system 500 via the three-winding transformer 400 has been described. However, for example, the SVC 200 is connected to the power system 500 via the first two-winding transformer, and the generator 300 is connected to the power system 500 via the second two-winding transformer. May be good.

In addition, it should be considered that each embodiment disclosed this time is exemplary in all respects and is not restrictive. The scope of the present invention is shown by the scope of claims rather than the above description, and is intended to include all modifications within the meaning and scope equivalent to the scope of claims. Further, the inventions described in the embodiments and the modifications thereof are intended to be carried out alone or in combination as much as possible.

100, 100A Control device, 110 1st calculation unit, 112 1st subtraction unit, 114 1st gain unit, 116 filter unit, 120 2nd calculation unit, 122 2nd subtraction unit, 124 2nd gain unit, 126 integration unit, 130, 302 Control unit, 132 Adder unit, 134 Generator unit, 150 controller, 162 ROM, 164 RAM, 250 Static power compensation unit, 300 generator, 400 winding transformer, 500 power system, 600 1st detector, 700 Second detector, 1000 power system.

Claims (8)

A generator that is connected to the power system and outputs active and reactive power,
A static power compensator that is connected to the power system and outputs static power,
A control device that controls the static power compensator and
A first detector that detects an active power value output from the generator and an ineffective power value output from the generator, and
A second detector for detecting an active power value output to the power system and an inactive power value output to the power system is provided.
The control device is
A first calculation unit that calculates the first quantity based on the difference between the value based on the active power value detected by the first detector and the inactive power value detected by the first detector, and the first calculation unit.
The difference between the value based on the active power value detected by the second detector and the reactive power value detected by the second detector, or the value based on the active power value detected by the first detector. A second calculation unit that calculates the second quantity based on the difference from the reactive power value detected by the second detector, and
A power system including a control unit that controls an invalid power value output from the static power compensator by adding the first quantity and the second quantity. The first calculation unit is
The first target value is calculated by multiplying the active power value detected by the first detector by a coefficient.
The power system according to claim 1, wherein the operation amount for setting the static power value output from the static power compensator to the first target value is calculated as the first amount. The second calculation unit is
The second target value is calculated by multiplying the active power value detected by the second detector or the active power value detected by the first detector by a coefficient.
The power according to claim 1 or 2, wherein the operation amount for setting the static power value output from the static power compensator to the second target value by executing the feedback control is calculated as the second amount. system. The first calculation unit executes a filter process for removing a high frequency component from the difference between the value based on the active power value detected by the first detector and the inactive power value detected by the first detector. The electric power system according to any one of claims 1 to 3. The power system according to any one of claims 1 to 4, wherein the generator and the static VAR compensator are connected to the power system via a three-winding transformer. The control device included in the electric power system according to any one of claims 1 to 5. The static power compensator unit including the static power compensator and the control device, which is included in the power system according to any one of claims 1 to 5. It is a control method to control the static VAR compensator.
A step of detecting an active power value output from a generator and an invalid power value output from the generator, and
A step of detecting an active power value output to the power system to which the ineffective power compensator and the generator are connected and an ineffective power value output to the power system.
A step of calculating the first quantity based on the difference between the value based on the active power value output from the generator and the ineffective power value output from the generator, and
The difference between the value based on the active power value output to the power system and the invalid power value output to the power system, or the value based on the active power value output from the generator and the value output to the power system. The step of calculating the second quantity based on the difference from the invalid power value
A control method comprising: a step of controlling a static power value output from the static power compensator by adding the first quantity and the second quantity.

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