Robust adaptive high order sliding-mode optimum controller for sensorless interior permanent magnet synchronous motors

In this paper, a robust nonlinear controller for sensorless interior permanent magnet synchronous motors (IPMSM) is designed to track a desired reference which is computed by using a maximum-torque-per-ampere strategy (MTPA). The proposed controller ensures finite-time convergence of sliding variables despite parameter uncertainties and unknown load torque. Furthermore, from the measurement of the currents and the voltages, a new analysis of the observability property is developed. Then, an adaptive interconnected observer is designed to estimate the angular velocity, the position, the load torque and the stator resistance. Using a Lyapunov approach, an analysis of the closed-loop system stability is given. Simulation results are presented to confirm the effectiveness of the proposed method.