A simple closed-loop active gate voltage driver for controlling di C /dt and dv CE /dt in IGBTs

Abstract

The increase of the switching speed in power semiconductors leads to converters with better efficiency and high power density. On the other hand, fast switching generates some consequences like overshoots and higher switching transient, which provoke electromagnetic interference (EMI). This paper proposes a new closed-loop gate driver to improve switching trajectory in insulated gate bipolar transistors (IGBTs) at the hard switching condition. The proposed closed-loop gate driver is based on an active gate voltage control method, which deals with emitter voltage (VEe) for controlling diC/dt and gets feedback from the output voltage (v CE) in order to control dvCE /dt. The sampled voltage signals modify the profile of the applied gate voltage (vgg). As a result, the desired gate driver (GD) improves the switching transients with minimum switching loss. The operation principle and implementation of the controller in the GD are thoroughly described. It can be observed that the new GD controls both dvCE/dt and di C/dt accurately independent of the variable parameters. The new control method is verified by experimental results. As a current issue, the known trade-off between switching losses and EMI is improved by this simple and effective control method.