采用最小累积风险度法的含风电场电力系统发电机组检修计划

Generation Unit Maintenance Scheduling Based on Minimum Cumulative Risk Algorithm for Power System Containing Wind Farms

以等风险度原则为基础,以各检修时段风险度方差最小为目标函数,建立了含风电场的电力系统发电机组检修计划模型,提出了基于最小累积风险度的启发式求解方法。采用半不变量描述负荷、发电机组出力等随机变量,将等效持续负荷曲线的卷积和反卷积运算转化为半不变量的加减。采用离散化的方法将风电机组等效成多状态机组,进而求取风电机组停运容量的半不变量。考虑风电场出力的不确定性,采用半不变量法结合革兰–沙利叶(Gram-Charlier)级数展开法求解系统的风险度。通过寻找检修区间内累积风险度最小的区间确定待检修机组的检修位置。IEEE-RTS系统的机组检修计划结果验证了该最小累积风险度法的有效性。

Based on the principle of equal-risk and taking minimum variance of risk in all maintenance time intervals as objective function, a generation unit maintenance scheduling model for power system containing wind farms is built and a heuristic solution based on minimum cumulative risk algorithm for the built model is proposed. The random variables such as load, output of generation unit and so on are described by semi-invariants; the convolution and deconvolution operations of equivalent sustained load curve are turned into the addition and subtraction of semi-variants. The discretization method is used to make the wind power generation units equivalent to multi-state units, and then the semi-variants of wind power generation units＇ outage capacity are solved. Considering the uncertainty of wind farm output, the risk of power system containing wind farms is solved by semi-variant method combining with Gram-Charlier series expansion. By means of searching the interval with minimum cumulative risk within the maintenance interval, the maintenance interval of the generation unit to be maintained can be determined. The effectiveness of the proposed method is verified by the result of unit maintenance scheduling for IEEE-RTS system.