Combination switch with intelligent zero-crossing switching function

Abstract

The invention discloses a combination switch with an intelligent zero-crossing switching function. The combination switch comprises a control circuit and a silicon controlled rectifier (SCR) combination switch, wherein the silicon controlled combination switch comprises two unidirectional SCR1 and SCR2, a first electromagnetic switch K1, a second electromagnetic switch K2 and a resistor R, wherein the two unidirectional SCR1 and SCR2 are respectively provided with a control terminal G1 and a control terminal G2, and the two unidirectional SCR1 and SCR2 are connected in an anti-parallel manner to form a first wiring terminal A1 and a second wiring terminal A2, and a normally-opened contact K2-1 of the second electromagnetic switch K2 is connected with the resistor R in series; and two ends of a series circuit formed by the normally-opened contact K2-1 of the second electromagnetic switch K2 and the resistor R are connected to two ends of a normally-opened contact K1-1 of the first electromagnetic switch K1 in parallel. The combination switch disclosed by the invention has the advantages of SCR conduction during current zero-crossing, more reliable switching process and the like.

Description

technical field [0001] The invention relates to a composite switch for intelligent zero-crossing switching, which is a device for controlling switching of capacitors and an important part of a reactive power compensation device for a power grid, and the performance of the switching element has a great influence on the reactive power compensation device. reliability plays a very important role. Background technique [0002] In the implementation process of power grid transformation, it is often necessary to add a shunt capacitor reactive power compensation device, which plays a positive role in improving the quality of power supply voltage, tapping the potential of power supply equipment, reducing line loss and saving energy. [0003] Most of the early reactive power compensation devices used switching methods such as AC contactors and thyristor electronic switches. AC contactors will generate large inrush currents and overvoltages when capacitors are switched on and off, and...

AI Technical Summary

Problems solved by technology

The patent specifically describes that in the conduction process, the thyristor only has a trigger signal, but there is no voltage drop, and the conduction condition of the thyristor is not satisfied, that is, there is no voltage drop between the anode A and the cathode K of the thyristor, so , the compensation device with this structure cannot operate reliably under dynamic conditions

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