Development of DC-1MV Ultrahigh Voltage Generator for ITER

Abstract

This paper presents development results of a five-stage DC-1MV Ultrahigh Voltage Generator for ITER. Each generator outputs -200kV, and the total 5 generators are connected in series and outputs -1MV. In order to realize the DC-1MV output and 1-hour continuous operation, a feasibility of both gas insulation and gas cooling for semiconductor devices was validated. A simplified structure with stud-type diodes and heatsinks resulted in the compatibility of enough insulation distance and wide cooling surface. Withstand voltage tests and a temperature rise test were performed for the actual equipment of the rectifier and the step-up transformer. These test results verified the validity of the proposed design.