A Cost-Effective DC Circuit Breaker With Series-Connected Power Devices Using a Single Gate Driver

Abstract

In this paper, a solid-state circuit breaker (SSCB) suitable for high-voltage DC systems is presented. A single gate driver is used to drive multiple series-connected power semiconductor devices, leading to a compact, reliable, and cost-effective design. An accelerating capacitor in parallel with a diode is used to charge the gate capacitors of the upper devices without an additional gate driving circuit. Simultaneous turn-on and turn-off are realized similarly to the structure with individual gate drivers. It can achieve good static and dynamic voltage balancing with the help of metal oxide varistors (MOV). Compared to the conventional single gate driver structures, negative gate voltages for all the devices are guaranteed during the entire OFF state simply by using two transient-voltage-suppression (TVS) diodes. Thus, the notorious gate voltage oscillation and the severe voltage unbalance problems during the voltage recovery process are eliminated. An 800 V/100 A SSCB simulation and experimental prototype based on two series-connected IGBTs are built to verify the effectiveness of the proposed structure.

Keywords

• High voltage DC system
• single gate driver
• series-connected devices
• solid-state circuit breaker
• static and dynamic voltage balancing