电力系统动态安全域的实用解法

近年来，电力系统动态安全域（DSR)已越来越为人所接受，它可以提供更为丰富的安全信息，有着广阔的在线应用前景。该文基于暂态能量函数分析，推导出一种新的求取实用动态安全域(PDSR)的方法。通过大量的数值仿真计算表明，实用动态安全域(PDSR)可由描述各节点注入功率上、下限的垂直于坐标轴的超平面和描述暂态稳定性临界点的超平面围成。基于此事实，该文给出了一种快速计算对应于临界暂态稳定的边界超平面的直接法。这种方法是将溢出点处的暂态稳定域边界法矢量近似为常数，并通过线性化把事故后系统轨迹的切向量表示为注入功率的线性函数，然后依据在临界注入下两者之间的正交性，推导出了超平面型式PDSR边界的解析表达式。在新英格兰10机39节点系统上的测试结果表明了这种方法与数值仿真方法的一致性。

A PRACTICAL DIRECT METHOD FOR DETERMINING DYNAMIC SECURITY REGIONS OF ELECTRIC POWER SYSTEMS

The dynamic security region (DSR) of an electrical power system has been accepted more and more in recent years for providing plenty of security information and good prospect in online application. This paper presents a direct method for determining the practical DSR (PDSR) via the analysis of transient energy. Through a lot of simulations it has been shown that practical DSRs (PDSRs) of real power systems can be surrounded by the vertical hyper-planes that are the upper and lower limits of every bus injection, and one or several hyper-planes that describe critical points of transient stability in power injection space. Based on the above fact of PDSR, this paper develops a direct method for rapidly determining the hyper-planes corresponding to critical transient stability. The method firstly regards the normal vector of the boundary of transient stability region at the exit point as the constant vector. Next it shows the tangent vector of post-fault trajectory at the exit point as a linear function of power injections. Then, based on the orthogonal relation of the two vectors under critical power injections, a hyper-plane expression of the boundary of the PDSR is obtained analytically. The method has been evaluated on the 10-generator, 39-bus New England Test System, which agrees closely with the results of simulations.