Feedback-linearizing control of IPM motors considering magnetic saturation effect

This paper describes feedback-linearizing control of interior permanent magnet (IPM) motors which operate in magnetic saturation. First, we propose a current tracking controller for direct control of stator currents. Then, we explicitly characterize all torque controllers that can make the motor torque of an IPM motor exactly linear with respect to torque command even if magnetic saturation occurs. In particular, our torque controller contains a free function that can be used to achieve other control objectives as well as linear dynamic characteristics. Finally, the free function is chosen so optimal as to maximize power efficiency. The practical use of our control method is demonstrated through various simulation and experimental results.