含风电场交直流混联系统的概率潮流计算

Probabilistic power flow calculation for AC/DC hybrid system with wind farms

针对概率潮流问题中存在常规潮流计算不收敛的问题,建立含风电场交直流混联系统的概率潮流模型,采用交替迭代法进行每一次常规潮流计算,并采用改进的LM(Levenberg-Marquardt)方法求解潮流非线性方程组。分别考虑负荷、风速的不同相关性模型以及输电线路的随机故障,并讨论负荷的不同波动程度对概率潮流结果的影响。算例表明:改进LM方法具有较好的鲁棒性,能够在不同波动程度下得到较精确的结果;波动程度主要影响交流节点电压相角的均值和标准差,对结果中其他变量信息影响不明显。

Aiming at the non-convergence of conventional power flow calculation,a probabilistic power flow model of AC / DC hybrid system with wind farms is constructed. The alternate iterative method is employed in each conventional power flow calculation and an improved LM（Levenberg-Marquardt） method is applied to solve the nonlinear equations. Different correlation models of load and wind speed,as well as the random failure of transmission lines,are respectively considered,and the impact of load fluctuation degree on the probabilistic power flow is discussed. Case study shows that,as the improved LM method has better robustness,more accurate results can be achieved under different load fluctuation degrees;the load fluctuation degree mainly affects the mean and standard deviation of voltage phase-angle of AC node,while its influence on other variables is not obvious.