Interior PM Motor Torque Control and Performance Analysis Considering Saturation and Cross Magnetization Effects for Electric Traction

Abstract

In this paper, a detailed analysis over a reference electric vehicle’s drive cycle of an interior Permanent Magnet Synchronous Motor (IPMSM) is implemented, in terms of motor performance, efficiency and field weakening capability. Initially, the electromagnetic field characteristics of a geometrically optimized IPMSM are investigated for various modes of operation by using a 2-D Finite Element (FE) model. In a next step, a robust hybrid torque control model, combining direct Maximum Torque per Ampere (MTPA) control, for constant torque operation and Voltage Constraint Tracking (VCT), for Field Weakening (FW) operation is developed. For proper IPMSM control, the proposed model considers motor magnetic saturation and cross coupling effects between direct (d) and quadrature (q) axes, including the inductance variation with both d and q axes current. Finally, the effectiveness of the control model has been validated through New European Drive Cycle (NEDC) operation for the investigated vehicle.