This paper presents sliding mode control of sensor-less parallel-connected two five-phase permanent magnet synchronous machines (PMSMs) fed by a single five-leg inverter. For both machines, the rotor speeds and rotor positions as well as load torques are estimated by using Extended Kalman Filter (EKF) scheme. Fully decoupled control of both machines is possible via an appropriate phase transposition while connecting the stator windings parallel and employing proposed speed sensor-less method. In the resulting parallel-connected two-machine drive, the independent control of each machine in the group is achieved by controlling the stator currents and speed of each machine under vector control consideration. The effectiveness of the proposed Extended Kalman Filter in conjunction with the sliding mode control is confirmed through application of different load torques for wide speed range operation. Comparison between sliding mode control and PI control of the proposed two-motor drive is provided. The speed response shows a short rise time, an overshoot during reverse operation and settling times is 0.075 s when PI control is used. The speed response obtained by SMC is without overshoot and follows its reference and settling time is 0.028 s. Simulation results confirm that, in transient periods, sliding mode controller remarkably outperforms its counterpart PI controller.

Summary This article presents a new wind energy system using 2 five‐phase permanent magnet synchronous generators (PMSGs) controlled by a fifteen‐switch rectifier (FSR) topology for grid‐connected system. The 2 five‐phase PMSGs are connected to the DC link through a FSR; at its turn, the DC link is connected to the grid through a classical three‐phase inverter. In order to boost the control performance of the proposed wind system, a sliding mode control is adopted to control both generators‐side and grid‐side converters. The proposed control is tested under varying wind velocity and compared with a proportional‐ and integral (PI)‐based control system. The obtained simulation results show that the controlled variables follow their references independently of the wind speed fluctuations; and there is a significant reduction in the speeds overshoots by 100% and in the DC‐link voltage ripples by more than 78%. In addition, the total harmonic distortion (THD) of the generated current and grid current are reduced to 7.19% and 47.80% compared with PI regulators, respectively.

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