Dynamic switching control circuit for medium-voltage power capacitor

Abstract

The invention discloses a medium-voltage power capacitor dynamic switching control circuit, which is connected across the vacuum switch or contactor between the power grid and the capacitor, and includes: two voltage acquisition modules, one of which is used to collect the power grid at one end of the contactor Input voltage, the other is used to collect the output voltage at the other end of the contactor; the weak current switch is linked with the above-mentioned vacuum switch or contactor, and the controller is respectively connected to the output ports of the two collection modules to receive the input or Cut off the command, and output the corresponding trigger command to the trigger terminal of the weak current switch. The invention overcomes the defect of relatively lagging fast input response, and provides a circuit capable of realizing dynamic switching and fewer elements.

Description

technical field [0001] The invention relates to a synchronous switching technology of a power capacitor above 6KV, in particular to a circuit and a control method applied to a power capacitor to realize dynamic switching. Background technique [0002] The conventional circuit of switching power capacitor bank is: mechanical contact switching, thyristor switching (TSC), synchronous vacuum switch. The capacitor has a total of three possible states, the first is the first power-on (capacitor is not charged or has been fully discharged), the second is power-on operation (the voltage on the capacitor changes synchronously with the grid voltage), and the third is just Power off (the capacitor is in the discharge state, if the grid voltage waveform is in the negative half cycle before the power off, the capacitor is in the negative discharge state; the same is true for the positive half cycle); [0003] Mechanical contact switching switches, three-phase switches switch capacitors ...

AI Technical Summary

Problems solved by technology

[0005] The phase control switch used in engineering is also called synchronous vacuum switch or synchronous switch, such as the patent document "synchronous switch", patent number: ZL98808789.8, patent document "phase control switch device", patent number: ZL99118416.5, patent Document: "Phase Control Switching Equipment", application number: 00137229.7, also has 3 disadvantages: there are many synchronous switching elements, but the closing impact current is reduced, and the action time is the same as that of ordinary mechanical contact switching switches, which is too slow

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