LAUSR

In order to enhance the dynamic performance of surface-mounted permanent magnet synchronous machines (PMSMs), this letter proposes an improved finite control set (FCS) model predictive direct speed control (MPDSC) strategy that only contains one speed control loop. In comparison with the traditional two-step prediction method, the new controller is achieved by estimating the current at first and then the speed with only one prediction horizon. The practical problem that the optimal switching state cannot be selected by the common implementation procedures of the FCS model predictive control algorithms can be solved by applying the proposed strategy, which conforms more to the real situations. Moreover, in order to solve the other critical problem that the load torque (LT) in the predicting plant is unknown, a novel sliding mode LT observer is developed. The simulation and experimental results prove that the proposed algorithms are effective.