含风机电网静态电压稳定薄弱区域分析

Study on Weak Area of Static Voltage Stability for Grid Containing Wind Farms

电网中电压稳定事故常常由电压薄弱节点故障引起,进而蔓延至全网。风机接入电网后,其出力波动会导致节点电压薄弱程度变化,因此在分析电压薄弱区域时,需考虑风机出力的波动性。文中提出一种考虑风机出力波动性的电网静态电压薄弱区域分析方法,通过蒙特卡罗法,利用风速概率分布对风速抽样,计算风机不同出力下反映电网节点电压薄弱程度的LC指标,并通过统计分析估计电网的薄弱区域及其薄弱程度。以东北某区域电网为例,对含风机电网中薄弱区域进行了估计,并研究了风机容量对薄弱区域的影响对系统电压稳定性影响,该研究对含风机电网的实际运行具有指导意义。

The voltage stability accident of power grid is often caused by a fault of a voltage weak node and then spread to the whole grid. When wind farms are connected to the grid,the weak degree is affected by the fluctuation of wind farms＇ output. So it＇s necessary to consider the fluctuation when analyzing a grid＇s voltage weak area. This paper pro-posed a method on analyzing voltage weak area of grid considering the fluctuation of wind farms＇ output. Through Monte Carlo method,the wind speed is sampled with its probability distribution then the LC indexes which shows node＇s voltage weak degree are calculated. Through statistical analysis,the weak area of a grid containing wind farms is estimated.Take a regional gird of Dongbei for example,the voltage area is estimated. The effect of wind farms＇ capacity on weak areas is also studied. The paper＇s work is instructive to the actual operation of a grid containing wind farms.