Assessment of Preventive Control and Emergency Control Coordinating Economic Benefit

All the power generation companies, Load service entities and power grid companies are independent each other, so the consideration about system security and reliability are very different from it in traditional power system. The economic equivalent of security and reliability measure is based on the difference of the economic profits brought by the security and reliability measure and the cost needed by the implementation of the security and reliability measures. Characteristics and complementarities of both preventive control and emergency control, the status of the optimization of transient stability controls and their difficulties are reviewed from various viewpoints. This paper proposed that, it is very important for an interconnected power system under the marketing circumstance to coordinate between preventive control and emergency control. A coordination calculation model of economic equivalent is presented; the objective function is the sum of economic benefits for preventive control and emergency control. An optimization procedure based on Benders is proposed for the coordination, which integrates quantitative analysis of stability and a hybrid programming for non-convex nonlinear optimization. The economic equivalent gives an entirely new way for economic determination of power system security and reliability.