Fast Estimation Methods Of Self-Excitation And Transient Stability In Blackout Restoration

The power system is a large-scale and complex system, which has various components and network topological structures. Enlargement of transmission capacity, complement of power grid, decrease of network loss and stable system can bring active influence of social life. However, new problems may come out, which will bring disadvantages for power system, such as the blackout. The most famous blackout is the one of USA and Canada in 2003. In this case, how to form a plan of blackout restoration quickly, and ensure the restoration system keep safe and stable operation is a most important and valuable research.In this paper, two problems are chosen on research: generator self-excitation problem in black start and transient stability problem of restoration system. For self-excitation problem, a simple and approximate method is chosen to be the criterion. Then simulation of hydraulic generator self-excitation study is given. For transient stability problem of restoration system, the aim is to reduce the number of accidents that need to be analyzed particularly. Based on it, integrated performance index method is used to distinguish severe accident and non-severe accident. Then patulous integrated performance index method is presented, which can improve the efficiency of accident classification. After that, six indexes of integrated performance index method are used to design a self-organizing ANN classifier to estimate transient stability problem. By searching the rule of transient stability indexes, new samples are formed with the effect indexes to design new classifies, which can distinguish stable accident and unstable accident except for several illegible parts. It has better classified effect, so can help us to estimate transient problem quickly.The results of calculating samples indicate that self-excitation criterion can judge the problem well. It meets the requirement of quick restoration. Integrated performance index method and patulous integrated performance index method can recognize the severe degree of accidents. Self-organizing ANN can estimate the transient stability problem of power system by recognizing the accidents'characters quickly. It can reduce the number of accidents that need to be analyzed in details. Furthermore, all above methods are unnecessary to have complete calculation by time-domain simulation, so they are content to quickly calculation, and are proper to be use in online dynamic security assessment.