JPH0444779B2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field to Which the Invention Pertains] The present invention relates to a thyristor which comprises a plurality of so-called capacitor banks whose capacitors are opened and closed by thyristor switches, thereby compensating for load reactive power and suppressing fluctuations in circuit voltage. The present invention relates to an open/close capacitor type reactive power compensator.

[Prior art and its problems]

Conventionally, as shown in FIG. 1, a plurality of capacitor banks 3-1, 3-2, 3-3, . . . are connected to a load 1.
In the reactive power compensation system with 3-n, the load 1
A detection circuit 2a in the control device 2 detects the reactive power taken by the control device 2, and a selection circuit 2b determines the number of banks to be input based on this value.

Normally, as the load reactive power increases, 3-1, 3-1 and 3-2, 3-1 and 3
Input banks are added one by one in the pattern -2 and 3-3. Therefore, if a failure occurs among the input banks, if only the failed bank is disconnected and operated, the putter that the disconnected bank is involved in will inevitably have a lack of compensation capacity (see Figure 2). (see dashed line). Therefore, when disconnecting a failed capacitor bank, the bank insertion pattern described above must be changed as shown in Figure 3, and the settings may be changed manually or automatically. required a special circuit.

[Purpose of the invention]

An object of the present invention is to eliminate the disadvantages of the conventional method, and even if a capacitor bank is disconnected due to a failure or the like, it is possible to properly continue operation using the remaining capacitor bank without changing the bank injection pattern setting. An object of the present invention is to provide a reactive power compensator using a thyristor opening/closing capacitor system.

[Key points of the invention]

According to the present invention, this purpose is to compensate for the reactive power of the load and the capacitor bank in a reactive power compensator of the thyristor opening/closing capacitor type, which increases or decreases the number of capacitor banks to be input as the reactive power of the load increases or decreases. Means for detecting reactive power, and integral type adjustment for controlling the number of capacitor bank inputs so that the deviation between the detected values from both of these means is introduced through a dead band element, and the deviation is within the range of the dead band width. This can be achieved by having a vessel.

[Embodiments of the invention]

Hereinafter, embodiments of the method of the present invention will be explained in detail with reference to the drawings.

FIG. 4 is a circuit diagram showing an embodiment of the present invention, in which 1 is a load, and 3-1, 3-2, . . . 3-n are capacitor banks that are a combination of capacitors and thyristor switches. Reference numeral 2 denotes a control device for controlling the ignition of the thyristor in the thyristor switch of each bank.In addition to the reactive power detection circuit 2a of the load 1, the control device 2 includes the respective capacitor banks 3-1, 3-2, . . . 3.
A detection circuit 2c for compensating reactive power of the entire capacitor bank is provided, and the deviation between the detected output values of the detectors 2a and 2c is introduced into the integral regulator 2e via the dead zone element 2d. This dead band element 2d corresponds to a maximum capacitance of one step, and 2b in the figure is a bank selection circuit which receives the output from the regulator 2e and determines whether to increase or decrease the number of capacitor banks to be input.

In this way, the regulator 2e controls the capacitor bank 3-1 so that the deviation between the reactive power of the load 1 detected by the detection circuit 2a and the compensated reactive power detected by the detection circuit 2c is always within the positive and negative dead bands. ,3-
The number of inputs of 2,...3-n is controlled.

As a result, even after a specific capacitor bank is disconnected due to a failure or the like, operation can be resumed and continued without changing the input pattern.

As described above, the reactive power compensator of the present invention is a reactive power compensator of the thyristor opening/closing capacitor type in which the number of capacitor banks to be input is increased as the reactive power of the load increases. Even if there is a change such as disconnection, operation can be continued properly without changing the bank input pattern settings, so there is no need to manually change the pattern settings as in the past, and it can be changed automatically. There is no need for a special circuit for this purpose, and it can be streamlined.

[Brief explanation of drawings]

Figure 1 is a circuit diagram of a conventional reactive power compensator, Figure 2 is a diagram showing the capacitor bank input pattern in the circuit of Figure 1, Figure 3 is a diagram showing the input pattern after disconnecting a failed bank, and Figure 4. FIG. 1 is a circuit diagram showing an embodiment of the device of the present invention. DESCRIPTION OF SYMBOLS 1... Load, 2... Control device, 2a... Load reactive power detection circuit, 2b... Bank selection circuit, 2c
...Compensated reactive power detection circuit, 2d...Dead zone, 2
e...Adjuster, 3-1, 3-2, 3-3...3-n
...Capacitor bank.

Claims (1)

[Claims] 1. In a thyristor-opening/closing capacitor type reactive power compensator that increases or decreases the number of capacitor banks to be inputted as the reactive power of the load increases or decreases, means for detecting the reactive power of the load and the compensating reactive power of the capacitor banks, respectively; and an integral type regulator that controls the number of input capacitor banks so that the deviation between the detected values from both of these means is introduced via a dead band element and the deviation falls within the range of the dead band width. A reactive power compensator.