Operation characteristics of emitter turn-off thyristor (ETO) for solid-state circuit breaker and fault current limiter

Solid-state circuit breakers and current limiter can provide significant advantages in speed, lifetime and functionality compared to electromechanical switchgear used in distribution systems. The paper presents the operation characteristics of emerging ETO semiconductor power switch during turn-off transient. The gate commutating rate at turn-off, dI_G/dt, is improved to as higher as 12kA/mus. Experimental results demonstrates that a 75 mm ETO can safety interrupt 8kA current instead of 3 kA in GTO mode. Moreover, thanks to the built-in current sensor and the self-power generation for the gate driver, ETO will largely lower the cost of whole system. This device is suitable for solid-state circuit breaker and fault current limiter with its very fast switching speed, high current interruption capability, low conduction loss and compact structure