Development of Three-Phase Intelligent Composite Switch in Reactive Power Compensation

This intelligent composite switch is designed to overcome some application problems of mechanical switches and thyristor switches. The composite switch is composed of thyristors and general contactors and has two main advantages. Firstly, it can suppress capacitor inrush current through switching capacitors on crossing voltage zero or current zero. Secondly, heat loss caused by long-time conducting of thyristors can be reduced, and this is helpful for energy saving of switch itself. The hardware design & software design of the switch is given. Observing the device operating for a long time, we could safely conclude that the operation is meeting the standard and satisfying.