The Research Of Convertor Control Technology About Permanent Magnet Direct Driving Wind Power Generator

As a result of the serious energy shortage, wind power as a renewable energy become more and more been concerned. The direct driving wind power becomes one of the hot spots of wind power technology research. In the direct driving wind power system, converter put the transient power translate into the constant pressure and frequency power to connect with the grid. The improvement of converter control technology for improving power quality and efficient operation of generator has important means.First, introduce the development present situation of the wind power generator. Compared the commonly used converter structures, choose the back-to-back PWM converter to research. Analyzed the wind turbine, permanent magnet synchronous generator and PWM converter, and built their mathematical models. Then transform the mathematics models to other coordinates.Secondly, design the PWM control system of the generator side. According to the demands of the control system, built the double loop control based on the direct torque control strategy in the generator side. And built the simulation model of the system on the MATLAB. The simulation results show that the control system have high efficiency and stability. The generator could followed the wind speed and achieve the MPPT. The design could meet the system requirements.Finally, design the PWM control system of the grid side. In the wind power generator, the grid side converter is the direct link part between the unit and grid. Built the control system used the direct power control (DPC). But the switching frequency of the traditional DPC is variation, so increased the harmonic of the system power. Improve the DPC system based on the SVPWM, and built the simulate model of the control system. The simulation results show that the system also could keep the dc bus voltage stable, and reduced the power harmonic rate, improve the power quality.