Performance Improvement Of Semicontrolled Open-winding Pmsgs Based On Virtual Zero-crossing Detection And Segment Injection Of Third-order Harmonic Current

Performance Improvement of Semi-controlled Open-Winding PMSGs Based on Virtual Zero-Crossing Detection and Segment Injection of Third-Order Harmonic Current.

Abstract:   

The semi-controlled open-winding permanent magnet synchronous generators (OW-PMSGs) with a common DC bus system have received more attention in recent years due to its advantages of reduced cost and simpler power supply. Good control performances could be achieved under the zero power factor angle (PFA). However, current clamping problem is normally presented under non-zero PFA condition, resulting in unexpected torque pulsations and voltage pulse disturbances. Meanwhile, misjudgment of voltage vectors and subsequent deteriorations in steady-state performances can be observed at current zero-crossing points. In order to improve the control performances of semi-controlled OW-PMSGs, a virtual zero-crossing detection method is proposed in this paper to effectively suppress the oscillation of voltage vectors at current zero-crossing points. In addition, a segment injection strategy of third-order harmonic current is proposed. With the proposed strategy adopted, the current clamping problem can be successfully solved  and more importantly, the torque ripple and third-order harmonic current could be simultaneously suppressed..