基于风速-功率拟合与区间潮流的风电场电压波动预测

Calculating the Voltage Fluctuation based on Wind Velocity-wind Power Fitting and Interval Power Flow for Wind Farm

风机发电功率具有明显的波动性,将造成电网电压波动。根据历史风速数据预测风电接入可能造成的电压波动量,有助于选择最优的入网点或配置治理方案。本文提出一种基于区间运算的预测方法,根据风速数据预测风电机组接入后的电网节点波动量。首先建立风力发电机的最大风能跟踪控制和有功、无功解耦控制模型,从仿真数据拟合风速与风力发电功率的关系模型,预测风力发电功率的变化区间。此后基于高斯-塞德尔迭代法求解区间潮流方程,最后根据节点电压区间值预测风电机组并网运行后造成的电压波动量。采用蒙特卡罗随机潮流验证了本文方法的有效性和正确性。

The power fluctuation of wind generator would cause voltage fluctuation on the power grid. Voltage fluctuation prediction based on historical measurements of wind speed is useful for the optimal choice of grid-connected node or governance method. This paper introduces an assessment method based on interval arithmetic. According to historical measurements of wind speed, this method could estimate the voltage fluctuation caused by the wind farm. Study the maximum power point tracking method and the active power and reactive power decoupling control, then build the simulation model of DFIG to get the relation function between wind speed and output power of DFIG with fitting method. With the predicted interval value of wind turbine output, figure out the voltage fluctuation by solving the interval iteration equations which are based on Gauss-Seidel algorithm. Verify the validity and feasibility of this method by Monte-Carlo probabilistic load flow.