Design of an Intelligent Composite-switch for Reactive Power Compensation

This paper formulates the compound switch's working principle, compensation mode and implementation, it also expounds the design of hardware circuit structure. Aimed at the problems exist in the application of contactor and the power electronic device in the reactive power compensation equipment lonely, a kind of capacitance casting-chipping composite switch which is using the parallel connection of thyristor and magnetic latching relay as the main loop was designed to be applied in reactive power compensation equipment based on PIC When the equipment is switch-on, the electric current is taken on by the magnetic latching relay lonely, the advantages are that the power consumption of touch point is low and the capability of the anti-interference to harmonic is strong. The surging current at operating capacitor by thyristor passing zero is small and the reaction of compensate is quickly by the concerted action between the magnetic latching relay and thyristor, during the switching process. The PIC can monitor the multiplex signal circuit and control the magnetic latching relay and thyristor reliably. This equipment can successfully achieve in the trouble shooting, trouble removal and trouble indicator.