JPS63174525A - Capacitor equipment switchgear - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] The present invention relates to a control method for a capacitor equipment switchgear.

Specifically, the present invention relates to a control method for a capacitor equipment switchgear that opens and closes a phase advance capacitor in a power system using an electromagnetic switch as the main component and a static switch configured by connecting thyristors in antiparallel.

This type of capacitor equipment switchgear is connected in parallel with a customer's load, for example, to detect the reactive power in that load, compare it with a reference signal, and apply an ignition control signal to the switch gate to activate the switch. Controls energized reactive power by turning it on and off.

FIG. 1 shows an example of a conventional capacitor equipment switchgear.

The circuit configuration in FIG. 1 will be explained.

A series reactor 3, a capacitor 4, and a thyrisk switch 5 are connected in series to an AC power source 1 via a circuit breaker 2. .

Thyristor switch 5 includes thyristor 5a and thyristor 5
b are connected in antiparallel.

Although the figure shows one phase, it is usually three-phase.

Here, the size of the capacitor 4 is determined by the size of the consumer's load.

Due to the varying magnitude of reactive power, capacitors are provided to compensate for this.

The individual capacitors are connected through their own switches.

Therefore, if the unit capacitor is made large, a large capacity switch 5 is required, and if the unit capacitor is made small, a large number of switches 5 are required.

In any case, the price of the switch 5 increases in proportion to the size of the capacitor 4.

The problem here is that the thyristor switch 5 is very expensive, and it greatly influences the price of the entire device.

The present invention has been made in order to solve such problems, and by slightly changing the circuit configuration, the thyristor switch 5 is made into a short-time rated, small capacity thyristor switch 5, thereby reducing the cost of the entire device. be.

FIG. 2 shows the capacitor installation switchgear of the present invention.

The circuit configuration shown in FIG. 2 will be explained.

A series reactor 3, a capacitor 4, and an electromagnetic switch 6 are connected in series to an AC power source 1 via a circuit breaker 2.

A cyrisk switch 5 is connected between both terminals of the electromagnetic switch 6.

In the conventional FIG. 1, the thyristor switch 5 had all the opening/closing functions, whereas in FIG. 2 of the present invention,
The electromagnetic switch 6 plays a main role in the switching/closing energizing function, and the thyrisk switch 5 plays a supplementary role to the main switch 6.

The electromagnetic switch 6 is cheaper than the thyristor switch 5, and is suitable for opening and closing large capacitors from a cost standpoint.

If the electromagnetic switch 6 is used alone, the contacts will be severely worn out due to the inrush current of the capacitor, and the electromagnetic switch 6 will
life span becomes shorter.

Therefore, it is necessary to prevent only the inrush current of the capacitor from flowing into the electromagnetic switch 6.

This role is played by the thyristor switch 5 connected in parallel between both terminals of the electromagnetic switch 6.

Since the thyristor switch 5 is capable of zero-cross switching, it is possible to avoid the influence of the inrush current of the capacitor.

In order to take advantage of the respective characteristics of both switches 5 and 6, the thyrisk switch 5 is used only for the first short period of time when the capacitor is opened and closed, and the electromagnetic switch 6 is used for passing large currents for a long time.
to take charge of the matter.

Therefore, the thyristor switch 5 has a short energization time, does not require large heat dissipation fins, and can be used even with a small capacity.

The overall cost of the device is reduced because the number of types of switches increases or the more expensive switches have smaller capacities.

The operation of the circuit shown in FIG. 2 of the present invention will be explained step by step.

When the capacitor 4 is turned on to the power supply, a conduction signal is supplied to the thyristor 5, and after a predetermined time has elapsed after supplying the conduction signal, a closing command signal is supplied to the electromagnetic switch 6, and the electromagnetic switch 6 is turned on. After confirming that, the supply of the conductive signal to the thyristor 5 is stopped.

Next, when opening the capacitor 4, a conduction signal is supplied to the thyristor 5, and after a predetermined time has elapsed after supplying the conduction signal, an open command signal is supplied to the electromagnetic switch 6, and the electromagnetic switch 6 is opened. After confirming that, the supply of the conduction signal to the thyristor 5 is stopped.

In this way, the present invention aims to maximize the respective characteristics of two different types of switches and to minimize the cost of the entire device.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing the configuration of a conventional capacitor equipment switching device, and FIG. 2 is a circuit diagram showing the configuration of the capacitor equipment switching device of the present invention.

Claims (1)

[Claims] 1) A capacitor equipment switchgear in which a static switch in which a thyristor is connected in anti-parallel between the contacts of an electromagnetic switch is connected in parallel. 2) When turning on the capacitor to the power supply, supply a conduction signal to the thyristor, and after a predetermined period of time has elapsed after supplying the conduction signal, supply a closing command signal to the electromagnetic switch to confirm that the electromagnetic switch has been turned on. After checking, stop supplying the conduction signal to the thyristor. 3) When opening the capacitor, supply a conduction signal to the thyristor, and after a predetermined period of time has elapsed after supplying the conduction signal, supply an open command signal to the electromagnetic switch.After confirming that the electromagnetic switch has been opened, the thyristor Stop supplying the conduction signal to.