考虑同调约束的电力系统主动解列断面的搜索方法

电力系统主动解列是避免发生大停电事故和系统崩溃的有效保护措施,需要及时、准确地确定解列方案。文中提出一种考虑发电机同调约束的最佳解列断面的搜索方法。首先基于故障后广域测量系统(WAMS)提供的实时动态响应信息,利用改进拉普拉斯特征映射算法在线识别同调机群,利用发电机同调虚拟节点聚合同调机群,减小解列断面的搜索空间,然后利用加权拉普拉斯分群策略得到初始的解列断面。最后考虑断面有功功率的方向,利用启发式变邻域搜索算法确定最佳的解列断面,使得解列后各孤岛的净不平衡功率最小。文中方法能充分考虑不同故障模式所带来的同调行为的差异性,使得主动解列控制具有选择性和鲁棒性。通过新英格兰39节点系统验证了所述方法的有效性和适应性。

A Searching Method for Power System Controlled Islanding Surfaces Considering Coherency Constraint

Power system controlled islanding is an effective protection measure to avoid power system blackouts and system breakdown. It is necessary to determine the islanding scheme promptly and accurately. Based on generator coherency constraint, a searching method for the optimal islanding scheme is proposed. First, an improved Laplacian Eigenmap algorithm is used to identify the coherent generators according to the real-time dynamic post-fault trajectories obtained by wide area measurement system (WAMS). The network simplified graph with reduced searching space is then obtained by aggregating coherency generators using coherent generator virtual nodes. The extended Laplace partition strategy is applied to obtain the preliminary islanding surfaces. At last, by considering power flow directions, a variable neighborhood heuristic searching algorithm is used to search for the optimal islanding surfaces with the minimal net power imbalance within the islands. Simulations on the New England 39-bus system validate the effectiveness and flexibility of the approach proposed. The differences of coherent behavior by different fault modes are fully considered. This ensures the controlled islanding strategy with high selectivity and robustness.