基于风速变异系数的山地风电场模型风力机机械功率计算方法

Mechanical power calculation method of wind turbine in mountainous wind farm model utilizing variation coefficient of wind speed

文中利用变异系数作为风速非一致性指标,提出了一种山地风电场详细模型中风力发电机组功率的计算方法。该方法先建立山地风电场风速时空分布特征表,根据特征表中的变异系数及其置信水平获取风速的上分位点和下分位点。通过这种方式,可以形成一个带有最大值和最小值的风速域。进而得到该山地风电场的一个对应的风电机组机械功率域。利用PSS/E软件、案例分析在中国西南地区某高海拔山地风电场展开,涉及切入风速和平均风速两种工况。通过与传统平均风速方法的时域仿真结果比较,验证了所提方法的有效性和准确性,以及将变异系数作为风速非一致性指标的合理性。有益于考虑高比例山地风电风速非一致性和不确定性的电力系统动态特性分析。

This paper proposes a new approach for calculating mechanical power of wind turbine in the detailed model for mountainous wind farm employing variation coefficient as non-uniformity index of wind speed.Firstly,a spatial and temporal distribution characteristic table about wind speed in mountainous wind farm is built.Subsequently,the upper percentile and lower percentile would be acquired according to the variation coefficient and its confidence level from the characteristic table.By this means,a wind speed domain with the maximum and minimum values can be formed.Consequently,the corresponding domain for mechanical power of wind turbine in mountainous wind farm could be obtained.The dynamic simulation study has been carried on a high-altitude mountainous wind farm in southwest region of China using PSS/E.It includes two working conditions near cut-in wind speed and average wind speed.The results verify the effectiveness of the proposed method comparing with the traditional method using average wind speed,and also prove that it is reasonable for taking variation coefficient as a non-uniformity index of wind speed.Furthermore,some discussions would be useful for dynamic characteristics analysis considering non-uniformity and uncertainty of high-density wind power integrated power system in mountain areas.