Connecting tests of superconducting persistent-current-switch in a type of current transformer to 1 kWh SMES system

A full system of 1 kWh/1 MW module-type SMES (superconducting magnetic energy storage) has been completed at a substation in Fukuoka City. There is a need for a PCS (persistent-current-switch) with a quick response and large current capacity for use with a SMES system. We have investigated a superconducting PCS in a type of transformer which works according to the principle of a current transformer. A 900 A class PCS has already been manufactured. This paper describes experimental results with connecting tests of the PCS to a SMES which consists of two modules, each comprising a converter of 500 kVA and three superconducting pulse coils.