Research on Health Management of IGBT Based on Mechanism Model

Temperature sensitive electrical parameter method is widely used in junction temperature detection of power devices because of its non-contact and high sensitivity. However, the junction temperature model based on the least square method or neural network may deviate from the semiconductor physics of the device. In this paper, a "voltage rise time - collector current -junction temperature" detection model based on the switching process mechanism model of power devices is discussed. Based on semiconductor physics, the monotonic relationship between collector current and voltage rise time is analyzed and discussed, and its mechanism model is determined at different temperatures. Finally, a junction temperature model based on the mechanism model is established by using the high-power IGBT H-bridge inverter circuit test platform to verify the theoretical analysis. At the same time, it is verified that the aging analysis of power devices can also be discussed by mechanism model. The experimental results show that the relationship between IGBT collector current and voltage rise time is hyperbolic, and the rise time of collector current and voltage is unique and definite at each junction temperature. When IGBT aging occurs, the curve deviates from that of normal IGBT. And the IGBT junction temperature test results will produce a large error.