A 15-kA Solid-State Circuit Breaker Research and Development for the Switch Network Unit of the EAST Tokamak

This article describes the research, development, and testing of a 15-kA solid-state circuit breaker (SSCB) prototype applied to the switch network unit (SNU) of the Experimental Advanced Superconducting Tokamak (EAST). The circuit scheme composed of parallel connected integrated gate-commutated thyristors (IGCTs) and the diode bridge to realize bidirectional breaker ability is presented first. In addition, the stray inductances of the bus bars and the heat sinks for the current sharing of each IGCT are also considered in detail. Through ANSYS Q3D parameters extraction, the influence of structure stray parameters on the current sharing of power device in parallel is analyzed. Finally, the operation performance of the SSCB has been successfully tested up to the rated current of 15 kA and the maximum interruption voltage of about 2.0 kV, these experiment results verified the current sharing of the parallel-connected devices and the reliability of the SSCB during current conduction and current commutation processes.