Transmission and Distribution System Reliability Evaluation Based on Three-State Weather Model

Global weather condition is deteriorating, and the impacts on the transmission and distribution system are more and more serious. Therefore it is especially important to take the reliability impact assessment of the grid considering the weather factors. This article will divide the weather state into normal weather, bad weather and catastrophic weather, and establish the power system reliability evaluation model of three state weathers. Considering the elements in inclement weather can be maintained and in the disaster weather can not be maintained, analytical calculation algorithm for network reliability assessment including weather factors is derived. Through the case study, the results of three-state model are compared with that of simple two-state model, and the grid failure rate under three-state model is significantly higher than that under the two-state model. Network reliability Indicators are sensitive to the occurrence probability of catastrophic weather and the failure possibility in catastrophic weather. Analysis shows that the three-state weather model can fully reflect the impact of reliability on the grid, and verifies its correctness and effectiveness.