Junction Temperature Detection for IGBT Power Module Using Network Analyzer Methodology

This paper utilizes the network analyser procedure to determine the junction temperature of the insulated gate bipolar transistors (IGBTs) power modules (PMs). The process of detection is based on analysing the characteristic of the impedance for the Gate-Emitter (GE) loop of the IGBT module. Firstly, high frequency sinusoidal signals are injected into the GE loop, then the corresponding reflected data are captured to determine the impedance of the GE loop. After that, the magnitude response of the impedance is monitored to detect any variation in the junction temperature of the IGBT. Presumably, the process of detection is carried out during the idle state of the IGBT; therefore, EMI and noise issue can be avoided. In this test, Dynex 3.3 kV / 100 A IGBT module and Agilent E5071B network analyser are used. Experiential results clearly confirm the feasibility of the proposed procedure for detecting the junction temperature of the IGBT power module. This method can be easily transferred to other applications.