Machine-side Harmonic Suppression Strategy for Direct Driven Five-phase PMSG of Wind Power Generation System

Abstract

Wind power generation system with five-phase PMSG contains a large amount of third harmonic in the stator phase current of the machine side due to the dead-time effect of the converter and non-sinusoidal air-gap magnetic field. Harmonic suppression strategy is proposed to reduce output harmonics and improve the system's power quality. Firstly, the extended Clark&Park matrix was analyzed and applied to F-PMSG for dq decoupling control, and a mathematical model of the generator containing the fundamental and third harmonic subspace is obtained. Secondly, the third harmonic model of the stator current was analyzed. Based on the PI controller, a control strategy for the third harmonic subspace dual closed-loop control and the introduction of a harmonic compensation module into the feedback loop was designed. The dual closed-loop PI controller was used to adjust the dq-axis current signals without static error, and the harmonic compensation module was used to offset the accompanying harmonic voltage. Finally, a direct drive F-PMSG wind power generation system under maximum power point tracking was built in the Matlab/Simulink environment. The simulation results show that the strategy has good suppression effect on third harmonic generation.

Keywords

• wind power generation
• permanent magnet machines
• harmonic analysis
• closed loop systems
• power quality