Sensorless-oriented design of concentrated-winding IPM motors for HEV drive application

We present the design of a saliency-based sensorless drive interior permanent magnet synchronous motor (IPMSM) for a traction drive in hybrid electric vehicles (HEVs), and we introduce the sensorless safety operation region (SSOR), which accounts for cross-coupling magnetic saturation and harmonics of inductance distributions. The SSOR defines a working point under the maximum torque per ampere (MTPA) trajectory in which the motor can perform sensorless operation with a guaranteed performance in the steady state. The reliability of the SSOR was verified by experiments using two prototypes. The influence of the IPM motor geometry on the SSOR was then examined. Consequently, the design guidelines were established to obtain a suitable motor geometry that can maximize the torque capability and the stability during the sensorless drive. Under the restricted specifications of dimensions and requirements, the 100 Nm-10 kW 12-pole, 18-slot IPMSM is optimally designed for the target traction drive in HEVs. The validity of the proposed design was verified using a MATLAB/SIMULINK-based dynamic simulator.