A novel control strategy of power converter used to direct driven permanent magnet wind power generation system

This paper presents a novel control strategy of power converter used to direct-drive permanent magnet wind power system. The system consists of permanent magnet synchronous generator (PMSG), the generator side converter and the grid side converter. The voltage space vector PWM in field-oriented control is adopted in the control of the generator side converter. Both outer speed loop and inner current loop is implemented by a novel antiwindup PI controller. By means of the field-oriented control, the highest efficiency of wind turbine can be reached. The wind turbine is controlled to work at optimal tip speed ratio and to capture maximum wind energy. The control principle of grid-side converter was designed on the basis of the grid-side voltage oriented vector control. The outer voltage loop which is adopted fuzzy logic control method is used to keep DC-link voltage constant. And unit power factor gird connected inverter is realized, and current of grid-side is controlled to sine value by the control of inner current loop. Simulation and experiment results show that the controllers can regulate the voltage and frequency, extract maximum power under varying wind, and the novel control strategy has very good dynamic and steady-state performances.