Design and test of the bidirectional solid-state switch for an 160kV/9kA hybrid DC circuit breaker

Solid-state switch is one of the key components of hybrid DC circuit breaker (HDCCB). This paper proposed a bidirectional solid-state switch which is composed of series-connected IGBTs and diode bridges. The solid-state switch has the advantages of low cost, low stray inductance and high turn-off capability, which forms an 160kV/9kA HDCCB together with ultra-fast mechanical switches (MS) and a current commutation drive circuit (CCDC). In this paper, the characteristics of press-pack IGBT, IEGT and IGCT are compared. The turn-off tests of IGBT and IEGT at over 10kA are held. A novel switching module (SM) based on IGBT, diode bridge and external snubber circuits is proposed in order to achieve bidirectional switching with low costs. The series-connected SMs are mounted in a special clamp assembly with high accuracy and uniform pressure distribution. The stray inductance, mechanical property and thermal resistance of the assembly are analyzed. A prototype of the HDCCB demonstrated a successful current interruption within 3 ms at 68.5 kV and 7.2 kA, which verifies the performance of the HDCCB.