Development of a nonlinear loss minimization control of an IPMSM drive with flux estimation

This paper presents a nonlinear speed and loss minimization control (LMC) of an interior permanent magnet synchronous motor (IPMSM) drive to achieve both high efficiency and high dynamic performance. The control strategy is based on an input-output feedback linearization which ensures high performance speed control while minimizing the losses. Among all the losses, copper and iron losses can be precisely controlled and minimized by an optimal control of the d-axis stator current (i_d). The proposed LMC is developed based on motor model to produce optimum id for loss minimization. The global stability of the proposed drive system is verified through a Lyapunov's stability analysis. Also, a novel observer is applied to estimate the permanent magnet flux linkage (Ψ) online. The performance of the proposed nonlinear speed and LMC is demonstrated in simulation at different operating conditions. A performance comparison of the proposed LMC control scheme with the conventional control scheme is also provided.