网架重构过程中消除线路过载的环网恢复决策优化

Optimization Decision-making Method for Looped Network Restoration to Eliminate Transmission Line Overload in Network Reconfiguration

大停电后的电力系统恢复过程极为复杂,在网架重构阶段系统网架尚不完整,可能由于负荷的陆续恢复而出现部分线路潮流过载或重载的问题。该文提出一种以消除线路过载为目标的环网恢复策略,即投运部分待恢复线路,建立环状网络结构。首先对从树状网络过渡到环状网络的环网恢复策略进行了分析,并建立了直接计及交流潮流约束的线路过载消除的混合整数非线性规划模型。在此基础上,为提高求解效率,通过将原问题分解为主问题和子问题提出了环网恢复方案优化的分层迭代方法,其中主问题为计及直流潮流约束的线路过载消除的网架调整方案优化模型,子问题为合闸角约束校核和固定网架的交流潮流约束校核,通过主问题和两个子问题间的分层迭代得到最终的环网恢复方案。IEEE39节点系统算例和IEEE118节点系统算例验证了文中所提方法的有效性。

Power system restoration after blackout is a complex process. During the netv^ork reconfiguration process, transmission line overloads may possibly occur with gradual pickup of loads due to the weak structure of the restored network. In view of this problem, a looped network restoration strategy was proposed to eliminate the line overloads by restoring some unenergized lines in this paper. The looped network restoration strategy from a tree-type network to a looped network was analyzed first. Then, a mixed-integer nonlinear programming （MINLP） model considering AC power flow constraints was established. In order to improve the computational efficiency, a fast hierarchical optimization method for looped network decision-making was proposed, in which the original problem was decomposed into a master problem and two sub-problems solved iteratively. The master problem was defined as the looped network decision-making optimization problem with the DC power flow constraints. The sub-problems were defined as checking of the SPA constraint and AC power flow constraints to validate feasibility of the solutions of the master problem. The effectiveness of the proposed method was validated on the IEEE 39-bus and the IEEE 118-bus test system.