考虑风速相关性的概率潮流计算及影响分析

Calculation of Probabilistic Load Flow Considering Wind Speed Correlation and Analysis on Influence of Wind Speed Correlation

不同风电场之间风速的相关性会影响概率潮流计算的结果。通过对多维独立随机样本进行线性变换,得到具有任意相关性的多维随机样本,从而可计算考虑风速相关性的概率潮流;针对风电场异步发电机吸收无功的特性,提出了一种描述该特性的变系数二次多项式模型。在计及负荷随机扰动的同时,研究并分析了风速相关性的变化对节点电压概率密度和支路潮流概率分布的影响规律,以及考虑相关性后对风电场并网点无功补偿容量的配置。研究算例表明文中方法是有效可行的,考虑风速相关性可以更合理的分析评估风电场对系统静态电压和支路传输功率的影响,从而可为系统规划和运行方式的确定提供更准确完善的参考信息。

Correlation of wind speed among different find farms affects the calculation results ofprobabilistic load flows. By means of performing linear transform of independent multidimensional random samples the multi-dimensional random samples with arbitrary correlation are obtained, thus the probabilistic load flow in which the Correlation of wind speed is taken into account can be calculated. In view of the feature of asynchronous wind power generator that it absorbs reactive power, to describe such a feature a variable coefficient quadratic polynomial model is proposed. At the same time that the random disturbance of load is considered, the influencing variation law of wind speed correlation on nodal probabilistic density of nodal voltage and probabilistic distribution of branch load flow as well as the configuration of reactive power compensation capacity at grid-connecting point of wind farms under the consideration of wind speed correlation are researched and analyzed. Simulation results of IEEE 30-bus system to which four wind farms are added show that the proposed method is effective and feasible; considering wind speed correlation the analysis and evaluation of the influences of wind farms on system static voltage and transmission of branch transmission power can be more reasonable, thus it is possible to offer more accurate reference information to system planning and determination of operation modes.