Alternative temperature estimation approaches for sensorless permanent magnet synchronous machines

This paper proposes alternative methods for the estimation of the phase winding- and magnet temperature of a surface mounted permanent magnet synchronous machine. Different approaches for HF injection based temperature estimation are discussed and analysed. The conclusion for HF techniques leads to the design of a recursive least squares base estimation approach which with good properties regarding noise and bandwidth. A model based fusion of three temperature sensors serves as a reference for all experimental estimation results.