A Reliable Short-Circuit Protection Method with Ultra-Fast Detection for GaN based Gate Injection Transistors

This paper presents a new short-circuit protection method developed for Gallium Nitride (GaN) gate injection transistors (GITs). The proposed protection method is based on ultra-fast detection of the voltage dip on the phase leg of the converter, active current clamping of the gate drive, and fault confirmation with a low pass filter based de-saturation fault detection. Thus, it achieves an ultra-fast reaction and reliable protection for GaN GIT devices. The proposed protection method was experimentally validated with a 600 V rated commercial GaN GIT under single and repetitive short- circuit operations at 400 V. The total short-circuit fault response time was recorded within 224 ns, and the short-circuit energy is reduced with the ultra-fast detection and the active gate current clamping.