Maximum torque speed tracking control of IPM synchronous motor with state observers and load torque adaptive estimation

Based on maximum torque control principle, a speed tracking controller for an interior permanent magnet (IPM) synchronous motor is systematically designed in this paper. The control strategy mainly contains two stages, desired current determination and motor current control. Observers and adaptive laws provide information of state variables and load torque, which are not easily measurable. The stability of the controller and the convergence of tracking error as well as observed error are guaranteed by the design methodology, which is based on Lyapunov theory. Finally, the stability and efficacy of the proposed control system are verified by experimental results.