Battery Electric Vehicle Performance Evaluation by Considering Punching Effect on PMSM Iron Cores

Increasing demand for electric vehicles has put significant stress on designing highly efficient electric machines. Manufacturing processes of the electrical steel sheets used in the iron cores of machines deteriorate the electromagnetic properties of the material and increase iron losses. The improved quantification of iron losses in the early stages of the machine design is crucial and enables designers to properly account for losses. However, the complexity and variety of contributing factors in determining these losses have led machine designers to use empirical correction factors to predict iron losses reasonably well. In this work, deterioration of electromagnetic properties of electrical steel sheets due to punching has been considered when simulating the torque and loss performance of a permanent magnet synchronous machine. Three levels of degradation are investigated and the results show up to 10 %, 20 %, and 35 % increase in the hysteresis losses of the machine for a low, a medium and a high degradation level, respectively. Furthermore, the machine performance in selected test-driving cycles is determined as well.