三电平PWM整流器用于直驱风力发电系统

直驱型风力发电系统的风力发电机需要通过大功率交直交变流器即全功率变流器将风力发电机直接并网,而开关器件水平无法满足全功率变流器的要求,因此研究了二极管箝位三电平PWM整流器在直驱型风力发电系统中的应用。针对这一拓扑和直驱型风力发电系统的特点,采用基于PWM整流器模型的跟踪指令电压矢量的空间矢量脉宽调制(SVPWM)电流控制策略,使用龙格库塔解析法和Matlab仿真了负载从半载到满载变化时,三电平整流器直流电压的动态响应波形,交流侧电压、电流的变化趋势以及d-q坐标系下有功、无功电流分量跟随参考量变化的波形等。结果表明,该PWM整流器可有效抑制注入电网的谐波,减小交流侧的电流波形畸变;在负载突变时保持直流电压恒定,输出有功、无功可调且动态跟随性能较好。三电平PWM整流器作为全功率变流器的整流部分适合于直驱型风力发电系统的应用。

Research on Three-level PWM Rectifier Suitable for Direct-drive Wind Power

Diode-clamped Three-level rectifier which is suitable for Direct-drive wind power system is presented . In accordance with the topology and the characteristics of Direct-drive wind power system, a Space Vector Pulse Width Modulation (SVPWM) current control method based on the model of PWM rectifier and tracked instruction voltage vector is derived in detail, and simulation analyses based on the RungeKutta analytical method are also given in Matlab. The simulation results of the dynamic responses waveform of three-level rectifier DC voltage , the trend waveform of the rectifier AC side voltage and current, and the waveforms of current component of active and reactive power ,are also given. All of these results are obtained in the condition of load changing from half to full. The simulation results show that the harmonics is suppressed effectively, the distortion of AC current waveforms is decreased, the power factor can be adjusted, DC voltage almost keeps constant when load changes suddenly, active and reactive power can be adjusted, and for the change of active and reactive power,there is good dynamic follow-up performance. Therefore, as a part of full power converter, three-level PWM rectifier is suitable for Direct-drive wind power system.