A Study of Phase-locked Technology of Wind Power Generation Three-phase Grid-connected Inverter

This paper presents two phase-locked methods of wind power generation three-phase grid-connected inverter. First establishes the mathematical model of the inverter, on this basis analyzes why the power voltage phase must be known. And then studies the direct calculation method in alpha-beta coordinates, and analyzes the shortcomings of this approach for three-phase imbalance; then focusing on the phase locked loop (PLL) approach in d-q coordinate system. To solve dynamic response problem of the PLL, a new signal delay cancellation method is put forward. With this improved method, the PLL can have a better performance. Experimental results show that the theoretical analysis is real.