Application risk theory for transient security assessment of the real power system

The risk assessment approach has been widely used in power system for it has more advantages than traditional certainty approach and probability approach, such as, it can calculate two important indexes at the same time, the probability index of accident occuring and the serious loss index which result from the accident. This paper begins with a introduction of the fault probability model and the fault loss severity model. Then applys the risk theory to calculate four kinds of parameter risk index and one synthetical index to assess the performance of transient stability and its security in the real power system. The result shows it can be obtained not only the correcte sorts of transmission lines, but also the mainly unstability or unsafy type in power system which will help reasercher to adpot the correct prevention control measure. Compare with two system´s risk assessment results, it also can be seen the risk of transient security is related to the electrical network and its working manner. The conclusion that the risk assessment approach is practical and effective for power system transient security assessment can be drown.