SU1473005A1 - Method of switching three-phase capacitor installation - Google Patents

Abstract

The invention relates to the field of electrical engineering and can be used to regulate the power of a three-phase capacitor bank. The purpose of the invention is to increase speed. Semiconductor switches 4, 5 are connected between the first terminals 9-11 of the first 1 and second 2, second 2 and third 3 phase capacitors, respectively. Each of the semiconductor switches 6-8 is connected between the first output (9-11) of one phase capacitor 1-3 and the second output (12-14) of the previous phase capacitor 1-3. When phase capacitors are switched from star to delta, switch 4 is turned off at the moment current passes through it and zero is switched on switch 8 at time of residual voltage on capacitor 1 and key line voltage corresponding to it. zero and in turn, at the moment of residual voltage on the capacitors 2 and 3 and the corresponding linear supply voltages, turn on the switches 7 and 6. As a result, the capacitors 1-3 are connected in a "triangle" scheme. 2 Il.

Description

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The invention relates to electrical engineering and can be used to regulate the power of a three-phase capacitor plant.

The purpose of the invention is to increase speed.

Figure 1 is a diagram of the device that implements the proposed method; Fig. 2 shows voltage graphs on capacitors explaining the operation of the device.

The device contains phase capacitors 1-3 of the capacitor unit and semiconductor switches 4-8, made on bipolarly connected thyristors.

Semiconductor switches 4 and 5. included between the first terminals 9-11 of the first 1 and second 2, second 2 and third 3 phase capacitors, respectively. Each of the semiconductor switches 6-8 is connected between the first.: Output 9-11 of one phase capacitor 1-3 and the second output 12-14 of the previous phase capacitor 1-3.

The device works as follows.

In the absence of control signals, all switches 4–8 are disconnected and condensate-3 is disconnected from the network.

Let keys 4-5 be included and conden

Sisters 1-3 are connected according to the star. When switching phase capacitors 1-3 from a star to a triangle, first turn off the key 4 at the time of the passage of current through zero (Fig. 2, time t) and turn on the moment of equality of the residual voltage on the capacitor 1 and the corresponding linear supply voltage network key 8 (figure 2, time t,) .- Then turn off key 5 at the moment of the reagon

the current flow through it through zero (figure 2, time t) and alternately switch on keys 7 and 6 at time equal to the residual voltage on capacitors 2 and 3 and the corresponding linear supply voltages (figure 2, moments t and t), B As a result, capacitors 1–3 are connected according to the scheme

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Claims (1)

Invention Formula five 0 5 0 five 0 A switching method for a three-phase capacitor unit containing first, second and third phase capacitors, each of which has first and second terminals and controlled semiconductor switching devices, in which the first outlets of phase capacitors from the common junction point are disconnected at the time the current in the capacitors vanishes and alternately connect them to the second terminals of the adjacent phases of the capacitors at the moments of the residual voltage on each capacitor of the corresponding linear voltage In order to improve speed, the first step of the first phase capacitor is disconnected from the common point and connected to the second cable of the third phase capacitor, then the first phase of the third phase capacitor is disconnected from the first cable the second phase capacitor and connect it to the second output of the second phase capacitor, the first output of the second phase capacitor is connected to the second output of the first phase-capacitor capacitor. fi6 u to. K1 UK2 1 3 tif FIG. five