ABSTRACT With the elevation of power network voltage, the development of super-high voltage power network and the complexity of system structure, the department of power pays more attention to reliability of power system. Especially in the layout and design of power net, how to find the highest reliability project in existence, or to find the weakest segment of power network are very important. The department could spend the limited capital on the weakest segment to improve its reliability by using the modem theory of reliability. In this paper, reliability evaluation is discussed by the classical methods in power system: analysis. And the reliability equivalent model is investigated in detail. Based on the analysis of system running in norm and N-1 faults, the state analysis approach of the system is described. A power network’s reliability parameters are calculated to evaluate the reliability of the whole system.
KEY WORDS: transmission system ; reliability ; analysis