The systematic, synthetic and sequential preventing measures are one of the important methods of avoiding large-scale blackout. Most of the currently applied forewarning and preventive control systems focus on the dynamic, on-line and real-time security and stability analysis and precautions, but it is considered in this paper that proceeding from the whole process of power grid operation and production will better realize comprehensive prevention. The system engineering concept is applied to four important steps in power grid operation and production for direct security and stability analysis and preventive control. The crux of this method is security and stability analysis and the preventive control measures for four time step-up grades, i.e. weekly planning, daily planning, pre-operation and real time planning. The implementation and key techniques of a four-grade forewarning and preventive control system for secure and reliable operation of Henan power grid is described.

介绍了1起因110kV开关旁刀闸线夹断裂引起的电网及电厂停电事故,由于使用的线夹不符合设计要求埋下了事故隐患;线夹断裂引起弧光短路时,由于保护装置的直流电源存在的问题导致了电网事故的扩大;电厂孤网运行后,由于高压油动机性能不佳、调门未能迅速开启,引起机组跳闸。总结了事故教训并提出了有关改进建议。

The paper proposes the model of optimal preventive control based on voltage security in electricity market. The objective function is the minimization of total payments of preventive control and must ensure each bus have enough voltage security margin. The sensitivity of voltage security based on voltage stability index and the concept of equivalent reactive power compensation of generator is also introduced in the paper, and calculates the price of each reactive power compensation method based on their contribution in voltage security and the decrease of reactive power from generators is calculated. Computer tests on WSCC 9 bus system show the feasibility and reasonableness of the model.