Development of a 1-kA, 25-ohm magneticaliy controlled persistent current switch for SMES

A 1-kA, 25-Ohm magnetically controlled persistent current switch (PCS) was developed and tested. In a single test of the PCS, it was found that the pr imary consideration to realize switching from normal state to superconducti ng state, PCS recovery, for large current should he a control of PCS curren t. In a connecting test of the PCS and 1-MJ SMES, the PCS showed rapid swit ching characteristics of less than 0.4 s, In the persistent current mode op eration, PCS operation at 1 kA for a six-hour period was demonstrated. By t he various tests, primary factors affecting design of magnetically controll ed PCS are analyzed.