DFIG在微电网中的电压控制策略与小干扰电压稳定性分析研究

为增强微电网小干扰电压稳定性,针对含双馈感应风力发电机(DFIG)的风光柴微电网,DFIG无功控制采用V-Q下垂控制并引入积分逻辑环节,同时计算变风速情况下DFIG有功功率对应的无功功率极限,对V-Q下垂控制与积分环节进行限幅。通过小干扰分析法找出了一对反映微电网电压响应特性的典型特征值,分析DFIG无功下垂系数取不同值时对典型特征值分布轨迹的影响。为了解决无功下垂系数取较大和较小值时带来的问题,经过参数改进后既促进了DFIG参与微电网调压的效果,又使微电网拥有更好的小干扰电压稳定性。最后在DIg SILENT/Power Factory仿真软件中搭建微电网模型,通过动态时域仿真验证了所提策略和方法对促进微电网调压以及提高微电网小干扰电压稳定性的有效性。

Study on Voltage Control Strategy of DFIG in Microgrid andSmall-Disturbance Voltage Stability Analysis

In order to enhance the small-disturbance voltage stability of wind/photovoltaic/diesel microgrid including doubly fed induction generator (DFIG), DFIG reactive power control uses V-Qdroop control and the integral logic loop. The reactive power limit corresponding to the DFIG active power in the case of variable wind speed was calculated, so that the integral logic loop and the V-Qdroop control were limited. The typical eigenvalues reflecting the voltage response characteristic of the microgrid were found by the small-signal analysis method. The influence on the typical eigenvalues distribution when adopting different values of the DFIG reactive power droop coefficient was analyzed. In order to solve the problems caused by large and small values of reactive droop coefficient, after parameter improvement, the voltage regulation effect of DFIG was promoted and the microgrid has better small-disturbance voltage stability. The microgrid model using the software DIgSILENT/PowerFactory was estabished, and the effectiveness of the proposed strategy and method was verified by the dynamic time domain simulation.