Control of Direct-drive Permanent-magnet Wind Power System Grid-Connected Using Back-to-back PWM Converter

A strategy is proposed to control the direct-drive permanent magnet wind power system in this paper, and a back-to-back PWM converter control method is employed in both generator side and grid side. With respect to generator side, the optimum tip-speed radio is employed to achieve the maximum power point tracking. DC voltage control is used as external loop and current control is employed as internal loop to make DC voltage constant. Moreover, d-axis is used to control the active power while q-axis current in grid side is employed to control the reactive power. Simulation result show good performance and confirmed that the strategy works well.