电力大系统实用动态安全域

PRACTICAL DYNAMIC SECURITY REGIONS OF BULK POWER SYSTEMS

通过对一个实际电力大系统的研究表明 ,在一些重要的预想事故下 ,保证暂态功角稳定性的实用动态安全域 ( PDSR)边界 ,可在注入功率空间上由描述各节点注入功率上、下限的垂直于坐标轴的平面和描述暂态稳定性临界点的超平面围成。实用动态安全域边界超平面是针对实际电力大系统 ,利用数值仿真法搜索大量的临界点 ,并通过最小二乘法拟合得到的 ,因而它表征了真实系统的安全稳定特性 ,其误差可以满足工程应用的要求。同时对于复杂电力大系统可以利用关键节点来降维表示 ,其实用动态安全域易于表达、使用和可视化。在线应用时不仅可以确定在给定的注入下发生相应的事故后 ,系统是否可以保证暂态稳定 ,而且可以通过解析计算或观察得出注入功率空间各个方向上的稳定裕度 。

A study on dynamic security regions (DSR) of a bulk power system shows that the boundary of the practical dynamic security regions (PDSR) on injection space, which can ensure transient angle stability, is made up of the hyper-planes vertical to coordinates axes that represent upper and lower limits of the nodes injections, and a hyper-plane which describes critical points about transient angle stability for specific serious contingency. The PDSR is constructed by the least-square approach, which uses lots of critical points searched by numerical simulation on the bulk power system. So it shows characteristics on security stability of the actual system, and its precision can be accepted in engineering practice. This paper also puts forward that the key nodes of the complicated power system can reduce the dimension of PDSR. Such PDSR can be expressed, used and visualized easily. With its on-line application, not only whether the power system will guarantee its transient stability corresponding to the speci fic system operating condition and contingency can be obtained, but also stability margins in different directions on injection space by analytical calculation or observation. The supplied valid information can be used in transient stability monitoring and control in present (monopolistic) power system as well as in the deregulated electricity market.