A new two feed-back control method integrated in digital gate driver for large power IGBT

In high power applications, proper gate control strategy for insulated gate bipolar transistors (IGBTs) can increase their efficient and reliability. As to the feed-back control strategy, the key issues are the control speed and control stability. This paper proposed a new feed-back control method integrated in digital gate driver for high power IGBT. It aims for controlling the current and voltage slope suppressing the voltage overshoot and electromagnetic interference (EMI) in switching transient. The digital gate driver for large power IGBT detects the collector current and voltage in real time. Then the detected analog signal is digitally sampled and sent to the digital core on board. An algorithm similar to bang-bang control is deployed in forward control loop to adjust the gate drive resistance. The control stability and robustness can be guaranteed as a result. The whole detection and control process is accomplished in real time with only hundreds of nanoseconds. Thus, the proposed control method can optimized the IGBT switching transient with high reliability and time effectiveness. Experimental results validate the feasibility of the proposed feed-back digital control method.