Grid-Connected Harmonic Current Suppression of Permanent Magnet Direct Drive Wind Power Converter Based on Current Cross-Coupling Control

Due to the power-grid low-order harmonic voltage and the nonlinearity of power electronic devices, the grid-connected converter of wind power generation system produces grid-connected harmonic current. In order to improve the output power quality of full-power grid-connected converter of wind power generation system, based on the detailed analysis of the harmonic mathematical model of grid-side converter, a cross-coupling control strategy for suppressing the low-order harmonic current components is proposed in this paper. In this control strategy, the DC component of each grid-connected harmonic current is detected in the multi-synchronous rotating coordinate system, and the current cross-coupling control method is adopted to realize the accurate control of each harmonic current. The harmonic current cross-coupling controller is analyzed and designed in detail. The proposed control strategy takes into account the cross-coupling effect of each harmonic current, which can effectively reduce the interaction between each harmonic current and the fundamental current, and improve the stability of the system. Simulation and experimental test verify the correctness and feasibility of the proposed control strategy.