Online chip temperature monitoring using υce-load current and IR thermography

This paper presents on-state collector-emitter voltage (υ_{ce, on})-load current (I_c) method to monitor chip temperature on power insulated gate bipolar transistor (IGBT) modules in converter operation. The measurement method is also evaluated using infrared (IR) thermography. Temperature dependencies of υ_{ce, on} at load current is measured and temperature dependency calibration factor is formulated. This method needs a correction to compensate a deviation in the interconnection resistance from homogeneous temperature field in calibration to non-homogeneous field in loading. The correction parameter is obtained from a static calibration and the method is proposed in the paper. Ageing compensation in estimating the temperature is illustrated. The correction parameter is also analysed in finite element model and also investigated experimentally superimposing heat by conducting device for a longer time in the calibration.