Wide speed range operation of PMSM drives using nonlinear flux control techniques

This paper presents a nonlinear flux controller based wide speed operation of permanent magnet synchronous motor (PMSM) drive. An adaptive backstepping based nonlinear controller is developed to get the control laws while maintaining systems stability. For the nonlinear controller the flux is controlled based on maximum torque per ampere (MTPA) and flux weakening (FW) techniques for below and above the rates speed, respectively. The global asymptotic stability of the drive is demonstrated by Lyapunov stability criterion in conjuncture with Barbalat´s lemma. The system nonlinearities are also accommodated through the online estimation of critical parameters. The proposed nonlinear flux controller based PMSM drive is investigated in simulation using MATLAB/Simulink software. The global stability and robustness of the driver are verified through simulation results.