JPH036606A - Control method for static reactive power compensator - Google Patents

Abstract

PURPOSE:To attain the current balance between two units of SVC (stationary var-hour compensator) by detecting the deviation between a reference SVC and a follower SVC and feeding the detected deviation back to the follower SVC. CONSTITUTION:The deviation of current value between a reference SVC and a follower SVC is detected by an addition/subtraction circuit 11. This detected deviation is inputted to a proportion/integration circuit 12 via an integration arithmetic circuit 8. If the current value of the follower SVC is larger than that of the reference SVC, the output of the circuit becomes plus (+). As a result, the output of the circuit 8 increases and the output of the circuit 12 decreases together with reduction of the current value of the follower SVC respectively. For this purpose, the control thyristors 3 and 4 are controlled. Thus the current value of the follower SVC is equal to that of the reference SVC. In such a constitution, when plural SVCs are operated, the balance is secured between the reactive powers compensated by both SVCs and a highly effective operation is ensured for these SVCs.

Description

[Detailed Description of the Invention] [Purpose of the Invention (Industrial Field of Application)] The present invention relates to a static var compensator, particularly when a plurality of static var compensators are operated at the same time. The present invention relates to a method of controlling a reactive power compensator.

(Prior Art) FIG. 4 shows an example of the configuration of a static var compensator (hereinafter simply referred to as SVC) connected to a power system. In Fig. 4, 1 is a power system, 2 is a thyristus control reactor, 3.4 is a control thyristus, 5 is a gate pulse generator, 6 is a current transformer, 7 is a voltage transformer, and 9 is a reference voltage setting device. , 10 is a voltage detection circuit, 11 is an addition/subtraction circuit, 12 is a proportional-integral circuit, 13 is a current detection circuit, 14 is a filter circuit breaker, 15 is a filter, and 16 is a slope reactance. The reactive power output of a delayed phase reactive power generation section (hereinafter referred to as TRC) consisting of a thyristor control reactor 2 and control thyristors 3 and 4 connected in antiparallel is continuously variably controlled by the firing angle of the thyristor switch. The firing angle is S
It is determined by the setting state of the SvC control circuit, such as the VC detection voltage, current, reference voltage value, and slope reactance.

(Problems to be Solved by the Invention) Conventional SvC will be explained using FIG. 4. SVC
When attempting to operate with two reference voltage setters 9 set to the same value, if the set value of the reference voltage setter 9 of the first SvC is small due to variations etc., the control system of the first SVC will be invalid. As the power output moves in the direction of increasing, the system voltage of the power system 1 in which the SvC is installed is affected and decreases.

Since the output of the voltage detection circuit IO decreases, the control system of the second SVC moves in the direction of canceling out the variation, thereby decreasing the reactive power output.

Conversely, if the setting of the reference voltage setter 9 of the first SvC is high, the control system of the first SvC moves in the direction of decreasing the reactive power output, but the control system of the second SvC moves in the direction of decreasing the reactive power output. S of
The reactive power output increases by moving in the direction of canceling the output of vC. That is, if the reference voltages vary when two SVCs are operated independently, the control system moves in the direction of mutually canceling the reactive power outputs, resulting in a problem that the system voltage cannot be controlled. Also, even if the reference voltage settings of two SvCs are the same, the voltage detection circuit of each SvC,
Differences occur in the outputs of the individual SvCs due to variations in the control circuits, etc., and the outputs of the two SVCs cannot be coordinated, resulting in problems similar to those described above.

An object of the present invention is to provide a control method for a static var power compensator that can compensate for current variations in two SVCs regardless of variations in control parameters such as reference voltage and variations in detection circuits, excluding the above-mentioned drawbacks. There is a particular thing.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above object, the present invention provides means for detecting a deviation between the current of the reference SVC and the current of the follow-up SVC, and a means for feeding back this deviation to the follow-up SVC. Provide means to do so.

(Function) In addition to conventional inputs such as reference voltage, the deviation between the current value of the reference SVC and the follow-up SvC current is input to the control system of the follow-up SVC to control the firing angle of the TCR and control the firing angle of the two SvCs. It is possible to balance the current.

(Example) The present invention will be described below with reference to FIG. In FIG. 1, 1 is a power system, 2 is a thyristor-controlled reactor, and 3.
4 is a control thyristor, 5 is a gate pulse generator, 6
1 is a current transformer, 7 is a voltage transformer, 8 is an integral calculation circuit, 9 is a reference voltage setting device, 10 is a voltage detection circuit, 11 is an addition/subtraction circuit, 12 is a proportional-integral circuit, 13 is a current detection circuit, and 14 is a A filter circuit breaker, 15 is a filter, and 16 is a slope reactance.

The deviation between the reference SvC current value and the follow-up SvC current value is detected by an addition/subtraction circuit 11, and is inputted to a proportional-integral calculation circuit 12 via an integral calculation circuit 8. For example, when the current of the follow-up SvC is larger than the current of the reference SvC, the output of the addition/subtraction circuit 11 becomes "+", the output of the integral calculation circuit 8 increases, the output of the proportional-integral circuit 12 decreases, and the output of the follow-up SVC Control thyristors 3 and 4 so that the current is small
is controlled so that the current of the follower SvC becomes equal to the current of the reference SVC.

Therefore, when the current of the follow-up SvC is smaller than the current of the reference SvC, the output of the addition/subtraction circuit 11 becomes ", but it similarly operates to balance the current.

In the embodiment shown in FIG. 1, the current balance operation of two SVCs has been described, but the same applies to the case of current balance operation of three or more SVCs. FIG. 2 shows a control block diagram when performing current balance operation of three or more SvCs. In Fig. 2, 1 is a power system, 2 is a thyristor control reactor, 3°4 is a control thyristor, 5 is a gate pulse generator, 6 is a current transformer, 7 is a voltage transformer, 8 is an integrating circuit, and 9 is a Reference voltage setter, 10 is a voltage detection circuit, 11 is an addition/subtraction circuit, 12 is a proportional-integral circuit, 13 is a current detection circuit, 14 is a filter circuit breaker, 15 is a filter, 16 is a slope reactance, and 17 is a reference SVC. automatic control system,
18 is an automatic control system of the follow-up SVC.

Similar to FIG. 1 showing the embodiment of the present invention, although the number of SVCs is different, current balance control can be realized by detecting the deviation between the current of the reference SVC and the current of each follower SvC and feeding it back to the follower SVC.

The same applies to the case of current balance operation of SvC including a phase leading reactive power generating section (hereinafter referred to as TSC) consisting of a thyristor switch connected in anti-parallel to a capacitance element.

FIG. 3 shows a control block diagram when performing balanced operation of SVC including TSC. In FIG. 3, 1 is a power system, 2 is a thyrisk control reactor, 3.4 is a control thyristor, 5 is a gate pulse generator, 6 is a current transformer,
7 is a voltage transformer, 8 is an integrating circuit, 9 is a reference voltage setter,
10 is a voltage detection circuit, 11 is an addition/subtraction circuit, 12 is a proportional-integral circuit, 13 is a current detection circuit, 1G is a slope reactance, 19 is a thyrisk control capacitance, 20 is a reactor, and 21 is a TSC on/off control logic.

The TSC on/off level control logic 21 performs on/off control of the TSC according to the output of the proportional-integral circuit 12, that is, the invalid seventh generation reference value. The follow-up SVC detects the deviation between the reference SVC current and the follow-up SVC current, and feeds it back to the follow-up SVC, thereby realizing current balance control in the same manner as in the embodiment shown in FIG.

As described above, according to the present invention, even when operating two SVCs including a TSC, the reactive power compensated by each SVC can be coordinated and efficient operation can be achieved. The same applies when three or more SVCs including TSCs are operated.

[Effects of the Invention] According to the present invention, when a plurality of SVCs are operated, the reactive power compensated by each SVC can be balanced and efficient operation can be achieved.

[Brief explanation of drawings]

FIG. 1 is a block diagram of one embodiment for realizing the control method of the present invention, FIG. 2 is a block diagram of another embodiment of the present invention for performing current balance operation of three or more SVCs, and FIG.
The figure is a block diagram of still another embodiment of the present invention in the case of performing current balance operation of an SVC including a TSC, and FIG. 4 is a block diagram showing an example of a conventional SVC control system. 1... Power system 2... Thyristor control reactor 3.4... Control thyristor 5... Gate pulse generator 6... Current transformer 7... Voltage transformer 8...
Integral calculation circuit 9... Reference voltage setter 10... Voltage detection circuit 11... Addition/subtraction circuit 12... Proportional integral calculation circuit 13... Current detection circuit 14... Filter circuit breaker 15. ...Filter 16...Slope reactance 17...Reference SVC control system 18...Following SVC control system 19...Thyristor control capacitance 20...Reactor

Claims (1)

[Claims] In a static reactive power compensator that includes a slow phase reactive power generator consisting of an inductance element and an anti-parallel connected thyristor switch provided in series with the inductance element, and performs reactive power compensation control, voltage fluctuation control, etc. of a power system, multiple units can be used. When operating the static var compensators at the same time, the reference static var compensator is operated so that the current of the standard static var compensator and the current of the follower static var compensator that follows it are equal. It is characterized by feeding back the deviation between the current of the reactive power compensator and the current of the tracking static reactive power compensator to the tracking static reactive power compensator to balance the reactive power outputs of the multiple static reactive power compensators. A method for controlling a static reactive power compensator.