中文摘要：

伴随系统法是用于电力系统暂态稳定分析的一种新方法。根据该方法，故障后电力系统的主导不稳定平衡点可以通过求解相关伴随梯度系统的渐近稳定平衡点得到。文中对上述方法做了进一步改进。对于故障清除后的电力系统所对应的非线性自治系统模型，可以构造一族与之相关的梯度系统，这些梯度系统共享一个势能函数和相同的平衡点。通过在状态空间中不同的点处选择势能下降快的系统进行积分，并考虑到误差控制，可以更快地找到稳定边界上的主导不稳定平衡点。IEEE 10机39节点系统的仿真结果证实改进方法有较明显的效果。

英文摘要：

Recently, a new direct method, called the adjoint gradient system method, has been proposed for computing the controlling unstable equilibrium point （CUEP） in transient stability analysis. According to this method, the CUEP of the postfault power system can be found by computing the asymptotic equilibrium points of the adjoint gradient system which is derived from the original system. A modification to the method mentioned above is made in this paper. It is found that there exists a family of adjoint gradient systems for a nonlinear autonomous dynamic system such as a post-fault power system. These adjoint gradient systems share the same potential energy function and equilibrium points. To compute the CUEP of a post-fault power system more quickly, the approPriate adjoint gradient system, whose potential energy decreases fast, should be chosen as the integral equation, and the error control should be taken into consideration. Simulation results in the IEEE 39 bus system prove that the modified method can speed up the computing of CUEP of a post fault power system efficiently.