Rotor Temperature Detection in Permanent Magnet Synchronous Machine-Based Automotive Electric Traction Drives

The detection of the rotor temperature in permanent magnet synchronous machine-based electric traction drives is a challenging problem for the automotive business. The goal of this paper is to provide a simple detection method that can answer to this problem. To this end, first the rotor temperature dynamics is modeled as a first order parameter-varying system. In this way, the resulting model depends only on the rotor mechanical speed and the stator temperature. Second, a polynomial approach for model parameters is employed. Then, an effective solution based on the system inactivity time is used for computing the initial value of the model. It yields a low-computational solution which is suitable for real-time implementation. The experimental results obtained on a prototype hybrid electric vehicle show good accuracy over a wide operating range.