Adaptive backstepping control for permanent magnet synchronous motor fed by three-level inverter

The basic principle of a novel voltage space vector modulation algorithm for the three-level inverter is developed. Aimed at the nonlinear characteristics of a PM synchronous motor, the backstepping control technique is studied. To improve the robustness of the speed controller, a simple adaptive control scheme is proposed. With the realization of the adaptive speed tracking control, the feasibility of an adaptive backstepping control scheme based on fuzzy neural network theory is presented and the stability is proved. The simulation results confirm that the two adaptive backstepping controllers both can improve the stability of the controlled system. It is illustrated that the latter control scheme using fuzzy neural network technique is robust for the uncertain system uncertainties, which has better control performance than that of the former control scheme. With the proposed voltage space vector modulation method, the controller performs simple mathematical calculations and reduces the harmonic distortions of output currents well.