An Online Condition Monitoring Method for IGBT Gate Oxide Degradation Based on the Gate Current in Miller Plateau

The reliability of power converters is one of the important issues due to the widespread applications of power electronics in many industrial fields. Accordingly, condition monitoring (CM) methods for the assessment of the health of the converter components are considered a practical topic for researchers and experts in the field. This article aims to propose a CM method for insulated gate bipolar transistor (IGBT) gate oxide degradation. The proposed CM is based on the gate-emitter current during the turning-on process. It is shown that in the degradation process, the gate current peak value majorly increases. The proposed CM method captures this peak value and uses it as a degradation indicator. The proposed method is simple and analogous and can be used easily for online health assessment of the IGBTs under operation. It can be integrated into the driver module to assess the gate oxide degradation of the device. The functionality of the proposed method is evaluated using experimental prototyping. The target devices are a 1200-V, 40-A trench-gate field-stop IGBT and a 600-V and 60-A planner gate punch-through discrete IGBT. The achieved results show the validity and acceptable performance of the proposed CM for detecting the gate oxide degradation of the device.