恢复潮流可行解的优化控制策略

An Optimal Control Strategy for Recovering Feasible Solution of the Power Flow

针对一系列预想故障,提出了一种恢复潮流可行解的优化控制策略。该策略采用恢复潮流解和恢复可行解的两步法,以最小控制代价为目标,把恢复系统可行解的控制问题转化为一类非线性规划问题求解。针对无潮流解的故障,利用最优切负荷算法恢复潮流解,同时利用模式分析法研究了节点注入无功功率对应关键电压失稳模式的参与因子,这些参与因子决定了在随后恢复可行解的过程中负荷切除和发电机出力调整的优先权。采用考虑离散变量的原—对偶内点法求解上述非线性优化问题。算例仿真表明,通过模式分析选择优化变量减小了优化问题的规模,提高了优化计算的收敛速度。

An optimal control strategy for recovering the feasible solution of the power flow under specified contingencies is proposed. This algorithm aims to minimize the control cost while recovering the feasibility of the power flow. The recovering process is transformed into a nonlinear programming problem which is solved in two steps, restoring solvability and restoring feasibility. The optimal load shedding method is used to regain power flow solutions under specified contingencies, while a modal analysis is made to determine the participation factors of each bus related to the key instability mode. These participation factors are used to determine a priority list for the optimal power flow tool to minimize the load shedding and re-dispatch of the active/reactive power generation. The primal-dual interior-point algorithm is applied to solving the integrated mixed-integer and nonlinear problem. The simulation results show that the modal analysis has reduced the dimensions of the problem and improved the converging speed, which is important for on-line real-time control.