A new scheme of full-power converter used for grid integration of variable-speed wind turbines

In this paper, an Interior Permanent Magnet Synchronous Generator (IPMSG) driven by a wind turbine is directly connected to multi-pulse rectifier lies in its ability to reduce the line current harmonic distortion of the generator. The rectifiers can be configured as 12-pulse rectifiers, powered by a phase shifting transformer with a number of secondary windings. Each secondary winding feeds a six-pulse diode rectifier. The dc output of the six-pulse rectifiers is connected to a voltage source inverter. The inverter is connected to the grid via an LCL-filter and the proposed control strategy for the grid-side inverter provides the highest capabilities of attenuating switching frequency components and damping the resonance. The information of wind speed and/or generator is observed from the rectified output voltage of the IPMSG for maximizing the output power of the wind turbine. Therefore, the proposed control algorithm does not require any speed sensor for wind speed. It must be noted that the construction and installation of the whole system are simple, cheap, and reliable.