A novel gate driver circuit for snubberless, low-noise operation of high power IGBT

A central issue in reducing the size and cost of power converters is the control of transistor voltage and current transients during the switching process. Load side snubbers and clamps are bulky and expensive. Increasing the gate resistors values is inexpensive and simple but switching times as well as power losses are increased A gate drive scheme is investigated which results in an acceptable compromise between switching speed, power dissipation and electromagnetic interferences (EMI). The paper begins with an analysis of the switching waveforms highlighting the device and circuit parameters which affect the switching characteristics. This is used to suggest how current and voltage transients and EMI can be reduced by suitably shaping the gate current. Experimental results are presented for an IGBT device in a hard switching application.