Self-Adaptive Active Gate Driver for IGBT Switching Performance Optimization Based on Status Monitoring

摘要

Compared to the conventional gate driver for the insulated gate bipolar transistor (IGBT), the active gate driver (AGD) not only reduces the switching delay but also suppresses voltage or current overshoot, however, at the expense of increasing the switching losses unavoidably. In this article, a self-adaptive active gate driver (SAGD) is proposed to further optimize IGBT switching performance, which is particularly suitable for applications where the load current varies over time or the dc bus voltage is changed. Since in such applications, AGD with fixed overshoot suppression ability will cause unnecessary switching loss, especially when the load current or the dc bus voltage is low. In contrast, with neither A/D nor D/A converters applied, the proposed SAGD indirectly detects the load current and dc bus voltage as time quantities, based on status monitoring, then self-adaptively chooses the optimal gate resistance increment online during the specific voltage or current rising phase. In this way, the current or voltage with overshoot is suppressed to be inside the safe operation area of IGBT while the switching loss is minimized, thus a better tradeoff between overshoots and switching losses is achieved. Finally, the feasibility of the proposed SAGD is verified by experiments.