Non-Invasive Parameter and Loss Determination in PMSM Considering the Effects of Saturation, Cross-Saturation, Time Harmonics, and Temperature Variations

摘要

Accurate determination of losses and parameters in wide speed, torque, and temperature conditions in interior permanent-magnet synchronous motor (IPMSM) used in electric vehicles (EVs) enables improved modeling of torque and efficiency, thus leading to enhanced design and control performance. This article develops a novel and non-invasive method toward the determination of machine parameters such as stator resistance, inductances, and PM flux linkage by considering the effects of saturation, cross-saturation, time harmonics, and temperature. The fundamental and harmonic losses are determined and their effects on the parameters are also incorporated. A coupled analytical and experimental procedure that involves solving the mathematical models for parameter, loss, and temperature determination using online terminal measurements has been developed. A lumped parameter thermal network (LPTN) model has been used to derive the stator core temperature, and the fundamental and harmonic copper and core losses have been solved considering the effects of the operating temperature. The effect of time harmonics is also included in the loss models. The results from the improved PMSM model using the derived parameters and the accuracy of the results from the developed method have been validated through experimental investigations on a laboratory traction IPMSM prototype.