JPS6194124A - Hybrid static reactive power compensator - Google Patents

Abstract

PURPOSE:To attain high-speed control accordant with the control responsiveness by using a controller for phase control of a reactor and using the voltage deviation signal for control of the make/break of a capacitor bank. CONSTITUTION:A reactive power compensator contains two capacitor banks and a reactor 2 and controls a thyristor switch 4 by the deviation given from a transformer 5, a voltage detector 6, etc. through an ignition angle controller 12 and a synchronizing arithmetic circuit 14. Thus the reactive power compensation is performed. This device detects the actual value of the system voltage through the transformer 5 and the detector 6 and applies the voltage deviation DELTAV obtained by adding 8a said actual voltage value to the set value 7 to a controller 9 to obtain the reactive power command value. The phase of the switch 4 of the reactor 2 is controlled via a nonlinear correcting circuit 11 and the controller 12. Thus the delayed reactive power is controlled. Furthermore said deviation DELTAV is added 8b to the output of a bias circuit 10. Then the capacitor bank is made nad broken via a level detector (bank selector) 13.

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention combines a capacitor switching type static static power compensator (TSC) and a reactor phase control type static reactive power compensator (TCR). The present invention relates to a so-called hybrid static var power compensator.

[Conventional technology]

As such a reactive power compensator, the applicant has already proposed the following device (Japanese Patent Application No. 71018/1982). FIG. 2 is a block diagram showing a reactive power compensator, which is an example in which there are two capacitor banks and one reactor bank.

In the same figure, 1 and 5 are transformers, 2 is a reactor, and 3
is a capacitor, 4 is a thyristor inch, 6 is a voltage detector, 7 is a voltage setter, 8a, 8b are adders, 9 is a voltage regulator (PI regulator), 10 is a bias circuit, 11 is a nonlinear correction circuit, 12 is a firing angle adjuster, 16 is a bank selector (level detector), and 14 is a synchronization calculation circuit.

That is, the system voltage is detected by the transformer (PT) 5 and the voltage detector 6, and the system voltage deviation Δ■ is detected by the system voltage and the system voltage setting 1 from the setting device 7 via the adder 8a. This voltage deviation Δ■ is input to a proportional-integral regulator (PI regulator) 9, and a reactive power command corresponding to the voltage deviation is determined from its output. Then, from this reactive power command value, a required capacitor bank is selected by a bank selector (level detector) 16, and a predetermined capacitor bank is introduced into the power system via a synchronous calculation circuit 14. At this time, the adjustment of reactive power by adding capacitor banks is done in stages, so the reactive power required for the grid cannot be completely compensated, and in most cases, an excess or deficiency (residual deviation) remains. Become. Therefore, by adding the capacitor bank and subtracting from the reactive power command value the output of the bias circuit 10 that outputs a signal proportional to the capacitance of the capacitors that have already been added to the system, the output of the adder 8b is Outputs a reactive power command value that cannot be controlled by turning on the bank. Therefore, the phase of the thyristor switch 4 is controlled by the firing angle adjuster 12 via the nonlinear correction circuit 11 which calculates the thyristor firing angle commensurate with this output value, thereby compensating for the excess or deficiency. In addition, in order to suppress the inrush current when the thyristor switch 4 is turned on, the synchronization calculation circuit 14 applies a switching signal to the switch 4 in synchronization with the time when the difference between the capacitor voltage and the grid voltage becomes the minimum. established for the purpose of

[Problem that the invention seeks to solve]

In other words, reactive power compensation by opening and closing the capacitor bank should suppress the inrush current when the capacitor bank is turned on.
Since a synchronized closing method is adopted in which the capacitor is turned on at the phase where the difference between the capacitor voltage and the grid (power supply) voltage is the smallest, reactive power compensation using a capacitor bank has a control delay compared to reactive power compensation using reactor phase control. When something happens, I get angry. Therefore, in order to perform reactive power compensation without causing disturbance to the power system when voltage fluctuations occur in the power system, the control constants of the PI controller 9 must be adjusted to match the synchronization input when reactive power compensation is performed using the capacitor switching method. It is necessary to decide based on the accompanying control response characteristics.

Therefore, reactive power compensation using reactor phase control, which has a relatively fast control response, causes the same control delay as capacitor switching type reactive power compensation, and the problem remains that sufficient characteristics cannot be exhibited.

[Means and actions for solving the problem] A capacitor opening/closing type reactive power compensator that controls advanced reactive power by opening and closing a capacitor bank, and a reactor phase that controls delayed reactive power by phase-sterilizing the reactor. In a hybrid type reactive power compensator combined with a controlled type reactive power compensator, a voltage deviation detector detects the deviation between the system voltage deviation value and a set value;
The reactor is controlled by a regulator that calculates the reactive power command value to be absorbed by the reactor phase control type reactive power compensator based on the L pressure deviation, and a signal proportional to the capacitor capacity already input to the system is output. The capacitor puncture is increased by a bias circuit, an adder that adds the output of the bias circuit and the voltage deviation, and a level detector that detects when this added value exceeds a predetermined level.

By controlling the reduction, reactive power control by phase control of the reactor can be realized with a faster response than before.

[Embodiments of the invention]

FIG. 1 is a block diagram showing an embodiment of the present invention.

Note that this embodiment is also an example in which there are two capacitor banks and one reactor bank.

As is clear from the figure, the various devices used in this embodiment are the same as those in FIG. 2, but the installation positions of the regulator 9, adder 8b, and bias circuit 10 are different. That is, in this ~, the actual value of the grid voltage is detected by the transformer (I'T) 5 connected to the grid and the voltage detector 6, and the actual value of the grid voltage and the set value are added to the polarity as shown in the figure by the adder 8a. The voltage deviation (ΔV) obtained by addition is input to the regulator 9, and the reactive power command value to be compensated for by the reactor is detected. This command signal is input to the risk switch 4 via the nonlinear correction circuit 11 and the firing angle regulator 12, thereby controlling the delayed reactive power flowing to the reactor. On the other hand, the voltage deviation ΔV obtained via the adder 8a and the output from the bias circuit 'IO, that is, the output proportional to the capacitance of the capacitor already input to the system, are added together by the adder 8b.

The level detector 16 monitors the output from this adder 8b, and when the output exceeds a predetermined level and continues for a certain period of time, additional capacitor bank is added, and when the output continues to exceed a predetermined level for a certain period of time or below. [Effects of the Invention] According to the present invention, a regulator is used to control the phase of the reactor, while a voltage deviation signal is used to turn on and cut off the capacitor bank. As a result, it is possible to perform high-speed control in accordance with the control response of the reactor for system fluctuations that can be compensated for by reactor phase control alone, and also for fluctuations that cannot be controlled by reactor phase control alone. In this case, there is an advantage that the capacitor bank can be quickly turned on and off.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG. 2 is a block diagram showing a conventional example of a hybrid static var power compensator. Symbol explanation 1.5...Transformer, 2...Reactor, 3...Capacitor, 4...Thyristor switch, 6...Voltage detection Vessel, 7...
...Voltage setting device, 8a, 8b... Adder, 9.
...Adjuster, 10...Bias circuit, 1
1... Nonlinear correction circuit, 12... Firing angle adjuster, 13... Level detector (bank selector), 14... Synchronous calculation circuit. Figure 1 Figure 2

Claims (1)

[Claims] A capacitor switching type reactive power compensator that controls advanced reactive power step by step by opening and closing multiple capacitor banks using predetermined switch elements, and a capacitor switching type reactive power compensator that controls reactive power in stages by opening and closing multiple capacitor banks using predetermined switch elements, and a capacitor switching type reactive power compensator that controls reactive power in stages by opening and closing multiple capacitor banks using predetermined switch elements. This is a hybrid static type reactive power compensator that compensates for reactive power in a power system by combining a reactor phase control type reactive power compensator that continuously controls reactive power. a voltage deviation detector that detects the deviation between a bias circuit that outputs a signal proportional to the capacitance of the bias circuit, an adder that adds the output of the bias circuit and the voltage deviation, and a level detector that detects whether the added value exceeds a predetermined level. , performing phase control of the reactor based on the output of the regulator, and turning on the capacitor bank based on the output of the level detector;
A hybrid static type reactive power compensator characterized by determining a cutoff.