Yukimori Kishida

Development of the high speed switch and its application

We have developed a high speed switch (HSS) with an electromagnetic repulsion mechanism and a new spring mechanism. The switch can open within 1 msec from the trip signal. Furthermore, we have developed and produced a hybrid switch consisting of the HSS and a thyristor. The hybrid switch has a break time of less than one cycle and an instant closing time, and little energy loss of the current-carrying period. The hybrid switch is applied to the bus tie position breaker and the solid state transfer switch for improving the stability of electric power supply. Another application of the HSS is the development of a current limiting device which consisting of the HSS, a counter pulse circuit and a limiting resistor. We investigated the ability of the HSS to interrupt the counter pulse current. The interruption ability depends on the value of di/dt at the forced current zero and does not depend on the value of the interruption current below the current level of 1200 A.