计及保护的电力系统暂态稳定性评价

在电力系统暂态稳定性分析和评估中计及保护系统的动作特性，使系统暂态稳定性评价的结果更为实际有效．为此，提出了一种利用投影法求解计及保护的电力系统暂态稳定性评价的临界能量新方法，此临界能量为关键线路上相应保护（关键保护）动作面上的最小势能．该方法采用势能梯度在关键保护面上的投影作为搜索方向，通过控制变量——发电机角度求解相应的网络节点电压及角度，使潮流方程得到满足，当沿着这个方向搜索到的点的相应势能值最小时，即为临界能量．以4机11节点系统（WCSS）和10机39节点新英格兰系统为算例进行了验证．结果表明，所提出的基于梯度投影的求解计及保护的电力系统暂态稳定性临界能量新方法在收敛性及准确性上均优于两阶段法．

Assessment of Transient Stability of Power System with Protection Operation

It makes the result be more practical and effective to include the characteristic of protection relay in the transient stability analysis and assessment of the power system. A method is presented to calculate the critical energy for the assessment of transient stability of the power system with protection operation using the projection method, the critical energy is the minimum potential energy of the protection surface of the key lines. The method treats the projection of the potential energy grad at the protection surface as the search direction, and the constraint of power flow equation is satisfied by using the control variable, namely generator angles, to solve the network bus voltage magnitud the critical energy of the system. that the convergence and veracity es and angles. Along the searching direction, the minimum potential energy is The WSCC and New England system are taken as examples. The result shows of the proposed method are better than those of the two steps approach.