Composite Disturbance Suppression Strategy for Current Loop of HSPMSG Based on High Frequency Disturbance Observer

For the current loop of high-speed permanent magnet synchronous generators (HSPMSGs), the super-twisting (STW) sliding mode control is an effective method to suppress disturbances and achieve high precision control. However, the high frequency of ac disturbances in HSPMSG normally requires a large control gain to suppress its effects, but an excessive gain will lead to system chattering. As a result, the STW controller is poor in suppressing high frequency ac disturbances in the current loop of HSPMSG. For improved suppression of high frequency ac disturbances and chattering in the STW controller, a compound control strategy based on the STW is proposed in this article. First, the fast STW (FS-STW) current loop controller was designed to improve the dynamic performance of the current loop. Then, an ac disturbance observer is designed to observe high frequency ac disturbances. By feeding the observed values back to the FS-STW controller, the suppression capability for high frequency ac disturbances is enhanced. Compared with the STW control, the proposed control scheme can suppress dc and ac disturbances simultaneously and improve the dynamic performance of the current loop. Finally, the effectiveness of the proposed control scheme is verified on an HSPMSG.