Implementation and Control of Dual Grid Connected Inverter for Wind Energy Conversion System

In direct-drive wind turbine systems, a dual PWM converter for grid interface and its control strategy are presented. Following introducing the full-size ac-dc-ac converter, the principle and advantages of the dual inverter are analyzed. With the proposed method it not only divides high-level currents, making existing equipments apply to large-scale systems, but also reduces the current ripple amplitude. In order to obtain minimum lower order harmonics, instantaneous current control is adopted, which brings sinusoidal current waveforms with little distortion even at a low switching frequency. The dc voltage controller is also designed. The simulation and experimental results prove that the scheme gives feasible and effective solution for wind energy conversion systems.