DSR Based Probabilistic Security Assessment Model Of Power System With Its Applications

Bulk power system is the objective requirement and the trend of the power industry and economic development, which makes the complexity and the scale of power system increased rapidly. Especially the introducing of power market made the uncertainty greater in recent years. So the research of the power system security and stability is very important.A probabilistic security assessment model of power system based on dynamic security region (DSR) was presented. Probabilistic insecurity indexes are the core of this model and applied to express the security degree of power elements as well as the whole system. In the model, not only the probabilities of critical factors are to be considered, but also the quantitative description of the security degree of system are to be made. The theory of DSR is used to reduce the computing time and to make the model more practical. The research results of probabilistic security assessment can be applied in making right decision of security control.Probabilistic insecurity indexes take into account the influences of some uncertainty factors on the system security (such as the fault rates, load fluctuations, fault location, fault resistance, etc.), and make the quantitative description of the security situation of the whole system and elements. The indexes also give the information of system stability margin and other, with great practical value. Based on these advantages, the application of probabilistic insecurity indexes were further researched in the following areas: the power system emergency control, security cost, comprehensive control, security pricing and allocation of security cost.The effectiveness of this model has been proved by the test on the New England 10-genarator 39-bus system.