TWO-LINE CHANGEOVER SEMICONDUCTOR SWITCH

摘要

PROBLEM TO BE SOLVED: To obtain a semiconductor switch which enables the use of a snubber constant matching with the dynamic characteristics of a semiconductor device to be used and enables the changeover between two lines without a power supply interruption regardless of a voltage detecting means and a load. SOLUTION: Large capacity capacitors 6a, 6b and 6c whose capacities are at least 50 times the capacities of the snubber capacitors 2a and 2b of a semiconductor switch MC1 are connected in parallel to the power supply side and the load side of the semiconductor switch MC1. With this constitution, a voltage can be detected normally at the time of a failure and at the time of a power supply interruption and, further, series resonances between instrument transformers 4a-4c and the excitation impedances of load side transformers can be avoided.