Temperature Co-Estimation of Stator Winding and IGBT Module of Automotive Electric Drive System Based on Sequential Current Pulse Injection

Monitoring the critical temperature of stator windings and power semiconductors is crucial for the thermal safety of electric vehicles (EVs). Embedding temperature sensors is the most common monitoring method used in industry yet is constrained by their lifetime. Temperature-sensitive electrical parameter (TSEP) detection is a promising characterization approach to condition monitoring for a single target. However, due to parameter coupling, there is still a lack of cost-effective thermal monitoring strategies with a homogenous approach for multicomponents. Also, TSEPs are limited by measurement accuracy, not-yet-decoupled resistances, and coupled voltage drop of power semiconductors. To solve these issues, a co-estimation method for the multidimensional temperature of insulated-gate bipolar transistors (IGBTs), their freewheeling diodes (FWDs), and stator windings are proposed. The combinations of TSEPs in the drive circuit are extracted by injecting the sequential current pulses. Then, the proposed multi-degree of freedom (multi-DoF) regression introduces the boundaries to decouple the TSEPs of IGBT and FWD and recurse the corresponding temperatures. Finally, substitute them into the identification algorithm for estimating winding temperature. The experimental results via a prototype permanent magnet synchronous motor (PMSM) test bench are given, and the absolute errors (AEs) of the three targets all remain below 9 °C.