Third harmonic injection based nonlinear control of IPMSM drive for wide speed range operation

Abstract

This paper presents a nonlinear controller incorporating third harmonic injection for wide speed range operation of interior permanent magnet synchronous motor (IPMSM) drive. Due to magnetic saturation, constant motor parameters lead to an unsatisfactory performance for the controller. Therefore, taking parameter variations into account an adaptive backstepping based nonlinear controller is developed for an IPMSM drive. Furthermore, a sinusoidal third harmonic injection (THI) technique is integrated to increase the DC bus utilization which facilitates a higher speed operating range. The field control permits extended speed range utilizing the reluctance torque. Stability of the control law state variables are demonstrated through Lyapunov stability criterion and global asymptotic stability is assured through the application of criterion supported by Barbalat's lemma. Feasibility of the proposed drive is tested in both simulation and experiment for laboratory 3.7kW IPMSM drive. A performance comparison of the proposed harmonic injection based nonlinear controller is shown with classical vector control and nonlinear controller without THI and parameter estimation.