JP2000078752A - Voltage/reactive-power controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To inhibit reactive power fed from a synchronous phase modifier by recognizing a reactive-power output supplied from the synchronous phase modifier by a voltage/reactive-power controller without adding a control circuit to synchronous phase modifier itself, and generating reactive power by controlling a power phase modifying equipment in an electric power substation. SOLUTION: Reactive power Qrc and voltage V2 are integrated and processed by a reactive-power integrating relay 17 and a voltage integrating relay 18 only in an AVR operation mode. Whether or not integrating processing exceeds a decision value and the state of the operation of a power phase modifying equipment is required is decided by a control-equipment selector circuit 19. Presence in any quadrant of a VQ control plane of an equipment needed for operation is judged. A synchronous phase modifier RC1 and a power phase modifying equipment capable of inhibiting the reactive power of the synchronous phase modifier RC1 in each quadrant most effectively are selected by the control-equipment selector circuit 19 in the first quadrant (V2+, Qrc+), the second quadrant (V2+, Qrc-), the third quadrant (V2-, Qrc-), and the fourth quadrant (V2--, Qrc+), and controlled by an LR control circuit 20 and an SC, ShR control circuit 21.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention detects reactive power and system voltage fluctuations in a power system, and controls a switching tap at the time of load of a transformer and a power phase adjusting device applied to the power system. The present invention relates to a voltage / reactive power control device for stabilizing power and system voltage.

[0002]

2. Description of the Related Art FIG. 5 shows, for example, a synchronous phase adjuster (hereinafter referred to as RC) connected to a power system and capable of changing the system voltage and the reactive power output of the power system, and a voltage / reactive power control device. FIG. 2 is a control block diagram of a conventional voltage / reactive power control device in a certain power system substation, showing the power supply (hereinafter, referred to as VQC).

In FIG. 5, 100 is VQC, 101 is RC, 102 is a primary bus of a substation system, 103 is a secondary bus of a substation system, 104 is a primary bus voltage detector, 105
Is a secondary bus voltage detector, 106 is a secondary current detector of the transformer 107, and 108 is a load switching tap (hereinafter referred to as LR) of the transformer 107. 109 is a transformer tap value detection circuit, 110 is a mode determination circuit for determining whether the operation mode is the RC operation mode, 120 is a static capacitor (hereinafter, referred to as SC) which is a power phase adjustment device, and 121 is a power phase adjustment device. Shunt Reactor (hereinafter, ShR)
).

The VQC 100 includes a determination circuit 111 for determining whether the RC 101 is in a voltage maintaining mode (hereinafter, referred to as AVR mode) or a reactive power maintaining mode (hereinafter, referred to as AQR mode), a sine wave voltage v ₂ and a sine wave current. AC measurement circuit 122 inputs the i ₂ for measuring the reactive power Q _2, AC measurement circuit for measuring the voltage V ₂ to a sine wave input voltage v ₂ 12
3, the target reference voltage V2s and the target reference reactive power Q1s and result of integral calculation program setter 124 as storage means for governing the setting and storage of the judgment value, the reactive power Q ₂ and program setter 124 target standard reactive power Q1s deviation integrating operation, reactive power integration relay 125 for outputting a judgment result to compare with the preset determination amount, the voltage V ₂
Voltage integration relay 126, which integrates the deviation between the voltage and the target reference voltage V2s of the program setting unit 124, compares the deviation with a predetermined determination amount, and outputs the determination result, the reactive power integration relay 125, and the voltage integration relay 126. An operation device determination circuit 127 for selecting an optimal power phase adjustment device based on the output result of the above, an LR control circuit 128 for controlling the LR tap 108 of the transformer 107, a power phase adjustment device SC120,
It is composed of an SC that controls the ShR 121, an ShR control circuit 129, and the like.

FIG. 6 is an explanatory diagram of a VQC control plane in the operating device determination circuit 127 of the VQC 100. In FIG. 6, reference numeral 501 denotes a first quadrant in a VQC control plane. The first quadrant is used to lower the system voltage and control the lowering of the tap position of the transformer 107, which is a power device capable of reducing reactive power. 50 where the fluctuation of
Reference numeral 2 denotes a second quadrant, which is a power device SC120 capable of lowering system voltage and increasing reactive power.
The region 503 is a third quadrant which is opposite to the first quadrant 501 in which the fluctuation of the system voltage is suppressed by opening the power system from the power system or controlling the power supply device ShR121 into the power system. A region 504 for performing control (raising the tab position), a region 504 for performing control (opening of SC, inputting of ShR) in the fourth quadrant, which is the reverse of the second quadrant 502, and 505
Is a dead zone where no control is performed.

Next, the operation will be described. Here, a voltage suppression method of a representative power system will be described with reference to FIG. By inputting the operation results of the reactive power integration relay 125 and the voltage integration relay 126 to the operation device determination circuit 127 (step ST101), if the operation execution determination result is obtained in the area of the second quadrant 502, SC, The SC 120 is opened by the ShR control circuit 129 to suppress fluctuations in the power system. The above determination is performed, for example, as follows. When the difference storage result ΔV ₂ (unit: V seconds) of the voltage integration relay 126 becomes ΔV ₂ = Z with respect to the preset V ₂ integration operation determination value Z, it is determined that the deviation has exceeded the operation determination level. The calculation condition of ΣV ₂ is implemented for each quadrant of the VQC control plane. That is, when the actual value of V ₂ is in the first quadrant is performed only integration operation in the first quadrant. if,
If the actual V ₂ value moves to another quadrant during the integration operation, the integration result ΔV ₂ currently being integrated is immediately reset to 0, and the integration is started in the destination quadrant.

That is, the VQC 100 sets a control target.
The target voltage value V _{vqc of} a certain time section and the target voltage value V _rc of a certain time section which are controlled by the synchronous phase shifter are not synchronized in a certain time section, that is, the target voltage value V _vqc is not synchronized in a certain time section. The target voltage value _Vrc is different. For example, the voltage control target value of 12:00 is V _vqc = 27.
The target voltage control value of 5.1 KV RC at 12:00 is V _rc = 274.9.
The case of KV may occur.

At this time, if the system voltage V2 is 275.0 KV unless VQC is locked, the VQC becomes V
2 <V _vqc , voltage raising control, RC is V2> V
Voltage reduction control is performed for _rc . For this reason, control with different control directions is performed simultaneously from two devices in the same substation, and as a result, a fluctuation (oscillation) occurs in the system voltage.

However, the mode determination circuit 111
Thus, it is determined whether the RC 101 is in the AVR mode (step ST102), and if not, the VQ control process is performed (step ST103). On the other hand, if it is determined that the AVR mode has been set, the system voltage suppression control of the RC 101 and the system voltage suppression control of the VQC 100 compete with each other, causing fluctuations in the system voltage. The integration result of the relay 126 is fixed to 0 to lock the integration operation, and as a result, the VQC control is locked (step ST104).

[0010]

Since the conventional voltage / reactive power control device is configured as described above, when the RC is operated in the AVR mode, the integral operation of VQC must be locked. However, when the amount of reactive power supplied by the RC reaches its limit, there is a problem that an operator must manually operate the power phase adjustment equipment. In addition, when the RC is operated in the reactive power maintenance mode (hereinafter, referred to as AQR mode), since the reactive power output is controlled independently, it is difficult to finely control the reactive power in the substation as a whole. There was a problem that.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and it is possible for a VQC to cooperate with an RC to suppress a voltage fluctuation of a power system without adding a control circuit to the RC itself. The VQC recognizes the reactive power supplied by the RC, and controls the power phase adjustment equipment in the substation to generate reactive power, constantly suppresses the reactive power supplied to the RC, and disables the RC in an emergency. An object of the present invention is to obtain a VQC capable of sufficiently exhibiting a power output.

[0012]

A voltage / reactive power control device according to the present invention comprises: a synchronous phase shifter for supplying reactive power to a substation connected to an electric power system; In order to control the secondary bus voltage and the reactive power passing through the transformer so as to be in the vicinity of a preset secondary voltage reference value and a secondary reactive power reference value, a load switching tap of the transformer of the substation and A voltage / reactive power control device having a power phase adjusting device to be supplied to or released from the power system, comprising: a reactive power detecting means for detecting the reactive power supplied by the synchronous phase adjuster; The computing means controls the reactive power supplied from the power phase adjustment equipment based on the detected reactive power.

The voltage / reactive power main calculation means of the voltage / reactive power control device according to the present invention is provided in the transformer so as to supply the same amount of reactive power as the reactive power supplied by the synchronous phase adjuster. It controls the raising and lowering of the tap of the tap changer and the opening and closing of the power phase adjustment equipment.

The voltage / reactive power control device according to the present invention comprises: a reactive power detecting means for detecting a reactive power supplied by a synchronous phase shifter; a mode recognizing means for recognizing a control mode of the synchronous phase shifter; Storage means for storing the reactive power output from the synchronous phase adjuster and the control target value of the system voltage, wherein the voltage / reactive power main calculation means calculates a deviation amount outside the target value range, and In order to control the reactive power output and the system voltage, a control command for raising and lowering the tap of a tap changer provided in the transformer and a control command for opening and closing the power phase adjustment equipment are transmitted.

The power phase adjustment equipment of the voltage / reactive power control device according to the present invention is a static capacitor or a shunt reactor connected to a substation.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below. Embodiment 1 FIG. FIG. 1 is a control block diagram of a certain power system substation having a function of adjusting the voltage and reactive power of the power system by applying VQC according to the first embodiment of the present invention. In FIG. 1, 50 is VQC, 1 is RC, 2 is a primary bus of a substation, 3 is a secondary bus of a substation, 4 is a primary bus voltage detector, 5 is a secondary bus voltage detector, and 6 is a secondary bus voltage detector. The transformer secondary current detector 8 switches the load of the transformer 7 under load (hereinafter, L
R is a tap), 9 is a tap value detection circuit of the transformer 7, 10 is an RC control circuit, 12 is SC, and 13 is ShR.

Reference numeral 11 denotes, for example, the RC control circuit 10
A state where a mode determines the mode determination circuit in contact (AVR = ON), 14 is an AC measurement circuit for measuring the reactive power Q _RC with a sine wave input voltage V ₁ and sinusoidal current i _RC, 15 AC measurement circuit that measures the grid voltage V ₂ by a sine wave input voltage v _2, 16 is a program as a storage means for storing the setting of the target reference voltage V2s and the target reference reactive power Q _RCS and integral calculation result judging value setter, 17 a deviation between the target reference reactive power Q _RCS target standard reactive power Q _RC program setter 16 and integral calculation, makes a comparison with a preset threshold quantity determination result to output reactive power integration relay 18 is the deviation integral calculation of the target voltage value v ₂ of the voltage V ₂ and the program setting unit 16, the voltage integrator relay for outputting compares the determination result of the preset determination amount, 19 the Mu Control device selection circuit which selects the optimum power equipment by the output result of the power integrated relay 17 and the voltage integral relays 18, 20 LR control circuit for controlling the LR tap 8 of the transformer 7, 21 power phase modifying equipment SC1
2. SC for controlling ShR13, ShR control circuit, 22
Is a current transformer. The components 11, 14 to 21 constitute the VQC 50. The components indicated by the reference numerals 17 to 19 constitute the voltage / reactive power main calculation means 51.

FIG. 2 is an explanatory plan view of the VQC control in the control equipment selection circuit 19, which is different from the conventional case shown in FIG.
Has become a state of being mirror-reversed in the axial next bus voltage V _2-wire. That is, the reactive power sign direction of RC1 as viewed from VQC 50 is opposite to the reactive power direction of normal VQC control.
Normally, the VQC detects the amount of reactive power of the transformer secondary, and controls the phase adjustment so that the reactive power is supplemented by the phase adjustment equipment of the substation. In the VQC cooperative control with RC1, in order to stop the reactive power output of RC1, a phase adjustment capable of generating reactive power equivalent to the reactive power output by RC1 is selected, and the excess is temporarily set. Generate reactive power in the system
Even if C1 does not output its own reactive power, it is recognized that the reactive power of the system is sufficient.

In FIG. 2, reference numeral 201 denotes a first quadrant, which releases the SC12, which is a power phase adjusting device capable of lowering the system voltage and increasing the reactive power, from the power system, or In the area where the fluctuation of the system voltage is suppressed by controlling the input of the ShR13 into the power system, reference numeral 202 denotes a second quadrant in the VQC control plane, in which the system voltage can be reduced and the reactive power can be reduced. A region in which the fluctuation of the system voltage is suppressed by the control for lowering the tap position of the transformer 7, which is a possible power phase adjusting device, is a third quadrant 203 which is a control opposite to the first quadrant 201 (opening of the SC12, opening of the ShR13). Input) area, 2
Reference numeral 04 denotes a fourth quadrant in which control is performed in the opposite direction to the second quadrant 202 (increase of the tap position), and reference numeral 205 denotes a dead zone in which no control is performed.

Next, the operation will be described. Here, the description will be given according to the flowcharts of FIGS. VQC5
The AC measurement circuit 14 and the AC measurement circuit 15 within 0 are RC1
The reactive power output Q _rC and the secondary voltage V ₂ are input (step ST1). Next, the mode determination circuit 11 confirms that the RC1 is operating in the AVR operation mode (Step S).
T2).

During the AVR operation mode, the reactive power Q _{rC is supplied} by the reactive power integrating relay 17 and the voltage integrating relay 18.
And performing the integration processing operation of the voltage V ₂ (step ST
3, ST4). Next, the control device selection circuit 19 determines whether or not the result of the integration operation exceeds the integration determination value and is in a state necessary for operating the power phase adjustment equipment (step ST5).
For a detailed method of determining the integral operation, see Japanese Patent Application No. 4-43022 (Japanese Patent Application Laid-Open No. 5-244719).
And Japanese Patent Application No. 5-49540 (JP-A-6-259).
155).

Next, based on the result of the integration determination, it is determined in which quadrant of the VQ control plane the equipment required for the operation is located (step ST6). In other words, the sign V of the voltage V ₂ and the reactive power Q _rC when the result of the integration operation determination indicates an operation determination.
o. Based on the state, it is determined which quadrant is currently located. The conditions are as follows: First quadrant: V ₂ +, Q _rC + Second quadrant: V ₂ +, Q _rC − Third quadrant: V ₂ −, Q _rC − Fourth quadrant: V ₂ −, Q _rC +

First quadrant judgment (step ST7), second quadrant judgment (step ST8), third quadrant judgment (step S7)
T9) The control device selection circuit 19 selects an LR tap and a power phase adjustment device that can most effectively suppress (reduce) the reactive power output of the RC1 in each quadrant in the fourth quadrant determination (step ST9). Then, the LR control circuit 20 and the SC and ShR control circuits 21 control the selected power phase equipment.

In the first quadrant, _ShR13 is used to suppress the generation of the reactive power Q _rC and reduce the system secondary voltage V _2.
Or opening SC12 (step ST
11), in order to reduce the suppressed and the system secondary voltage V ₂ of the generation of reactive power -Q _rC if the second quadrant, carried a tap lowering operation (step ST12), the reactive power if the third quadrant - In order to suppress the occurrence of Q _rC and increase the system secondary voltage V ₂ , the SC 12 is turned on or the ShR 13 is opened (step ST 13). If the determination is in the fourth quadrant, the generation of the reactive power Q _rC is suppressed. implementing the raising operation of the tap in order to increase the secondary bus voltage V ₂ (step ST1
4).

Next, the VQC 50 performs these controls,
It is confirmed that the power phase adjustment equipment has been operated (step ST1).
5) If the operation is normal, the process returns to the first operation (step ST1) to start the next operation (step ST1).
6).

[0026]

As described above, according to the present invention, RC
VQC recognizes the reactive power output supplied by RC without adding a control circuit to itself, controls the power phase adjustment equipment in the substation, generates reactive power, and disables the reactive power supplied by RC. Because it was configured to suppress the power output,
The RC enables immediate supply of reactive power in an emergency such as the occurrence of a power system accident, and the VQC cooperates with the RC to suppress power system voltage fluctuations without causing hunting, etc. There is an effect that a VQC device capable of keeping the reactive power within the target range can be obtained.

According to the present invention, the tap change of the tap of the tap changer provided in the transformer so as to supply the same amount of reactive power as the reactive power supplied by the synchronous phase shifter, and the control of the power phase adjusting equipment. Since the opening and closing are controlled, the fluctuation of the power system voltage can be suppressed with higher accuracy.

According to the present invention, upon recognizing that the RC is operating in the AVR mode, the reactive power output from the RC is measured, and the system voltage and the reactive power target value set in advance to VQC are determined. Calculate the deviation from the measured value,
When the deviation amount is larger than the control execution target value, the control is performed such that the tap up / down control command of the tap of the tap changer provided in the transformer or the opening / closing control command of the power phase adjusting devices SC and ShR is performed. In addition, there is an effect that a VQC device capable of selecting the most effective power phase adjustment equipment, transmitting a control command, and controlling the reactive power and the system voltage within the control target value can be obtained.

According to the present invention, as the power phase adjustment equipment,
Since the tap changer provided in the transformer, the static capacitor or the shunt reactor connected to the substation is used, the control can be easily performed.

[Brief description of the drawings]

FIG. 1 is a control block diagram of a power system substation to which a VQC device according to a first embodiment of the present invention is applied.

FIG. 2 is an explanatory plan view of a VQC control according to the first embodiment.

FIG. 3 is a flowchart of a control process of the VQC device according to the first embodiment of the present invention.

FIG. 4 is a flowchart following FIG. 3 of the control processing of the VQC device according to the first embodiment of the present invention.

FIG. 5 is a control block diagram of a conventional power system substation.

FIG. 6 is an explanatory diagram of a control plane of a conventional VQC device.

FIG. 7 is a flowchart of a control process of a conventional VQC device.

[Explanation of symbols]

1 Synchronous phase adjuster, 7 transformer, 8 LR tap, 11
Judgment circuit, 12 static capacitor, 13 shunt reactor, 14, 15 AC measurement circuit, 16 program setting unit (storage means), 17 reactive power integration relay (voltage / reactive power main calculation means), 18 voltage integration relay (voltage / inactive (Power main calculation means) 19 control equipment selection circuit (voltage / reactive power main calculation means), 20 LR control circuit, 21SC, ShR control circuit, 50 voltage / reactive power control device, 51 voltage / reactive power main calculation means.

 ──────────────────────────────────────────────────続 き Continued on front page (72) Inventor Kenji Kobayashi 1 Higashi-ku, Higashi-ku, Nagoya City, Aichi Prefecture Inside Chubu Electric Power Co. (72) Inventor Hiroshi Ichihara 1 Higashi-Shimmachi, Higashi-ku, Nagoya City, Aichi Prefecture Chubu Electric Power Stock In-house F term (reference) 5G066 DA01 DA04 FA01 FB02 FB07 FB17 5H420 BB03 BB16 CC04 DD03 EA30 EB13 FF07 FF22

Claims (4)

[Claims] 1. A synchronous phase shifter for supplying reactive power to a substation connected to a power system, and a primary bus voltage and a secondary bus voltage of the substation and reactive power passing through a transformer are set to a predetermined value. In order to perform control so as to be close to the secondary voltage reference value and the secondary reactive power reference value, there is provided a load switching tap of a transformer of the substation and a power phase adjustment device to be put into or released from the power system. In the voltage / reactive power control device, reactive power detection means for detecting the reactive power supplied by the synchronous phase adjuster, and the reactive power supplied from the power phase adjustment equipment based on the detected reactive power. A voltage / reactive power control device comprising: a voltage / reactive power main calculating means for controlling. 2. The voltage / reactive power main arithmetic means includes a tap changer for tap change of a tap changer provided in a transformer so as to supply the same amount of reactive power as the reactive power supplied by the synchronous phase adjuster. 2. The voltage / reactive power control device according to claim 1, wherein opening and closing of the power phase adjustment equipment are controlled. 3. A reactive power detecting means for detecting a reactive power supplied from the synchronous phase shifter, a mode recognizing means for recognizing a control mode of the synchronous phase shifter, a reactive power output from the synchronous phase shifter and a system. Storage means for storing a voltage control target value, and a tap provided in a transformer for calculating a deviation amount outside these target value ranges and controlling a reactive power output and a system voltage within the control target value. 2. The voltage / reactive power control device according to claim 1, further comprising a voltage / reactive power main arithmetic unit for transmitting a command for raising / lowering a tap of a switch and a command for opening / closing power phase adjustment equipment. . 4. The voltage / reactive power control according to claim 1, wherein the power phase adjustment equipment is a static capacitor or a shunt reactor connected to a substation. apparatus.