Modeling of Interior Permanent Magnet Machine Considering Saturation, Cross Coupling, Spatial Harmonics, and Temperature Effects

Interior permanent magnet (IPM) machine is one of the most widely used machine topologies in electric vehicles and hybrid electric vehicles nowadays. The idealized IPM machine model is commonly used in the analysis and simulation of IPM machine's control and drive system. However, nonlinearity and temperature effects will greatly influence the performance and characteristics of IPM machine. Without a precise IPM machine model, high-performance IPM machine control algorithm cannot be accurately evaluated in the simulation. This paper derived the IPM machine's voltage equations and torque equation considering saturation, cross coupling, spatial harmonics, and temperature effects. The derived IPM machine equations can use as high-fidelity IPM machine model with the assistance of lookup tables in the machine drive system simulation. The results in this paper facilitate the design of high-performance IPM machine controller, which is robust to temperature variation.