直驱型风力发电系统电网侧三电平变流器研究

RESEARCH ON THREE-LEVEL GRID CONVERTER OF DIRECT-DRIVE WIND POWER GENERATION SYSTEM

直驱型风力发电系统中风力发电机需要通过全功率变流器并网,电网侧变流器是全功率变换器中的关键部分。本文以三电平电压型PWM变流器作为直驱型风力发电系统电网侧变流器的主电路拓扑结构,建立了基于三相静止坐标系和两相同步旋转坐标系的数学模型,采用空间矢量脉宽调制技术,研究了电压、电流双闭环控制策略,并在PSCAD环境下,对其进行了仿真验证。仿真结果验证了电压、电流双闭环控制策略的正确性,并能够实现功率因数为1、稳定直流侧电压、无功功率独立调节的目的。

Abstract： Direct drive wind power system need full power converter to connecting the grid, grid - side converter is key to the whole power converter. In this paper, using three - level PWM voltage converter as grid side topology for the direct - drive wind power system, mathematical models of full power converter are Established based on the three phase stationary and the two - phase synchronous rotating coordinate system, the simulation takes the application of double dosed loop of voltage and current control strategy are carried out on the platform of PSCAD, Using space vector pulse width modulation principle. Simulation verified that the designed of converter can realizing unit power factor, DC link voltage steady controlled, Reactive power independently regulated, and good steady - state response and dynamic response.