Interval Power Flow Analysis Based on Type-II Fuzzy Logic Forecasting

In the traditional power flow analysis, the output of generator is controllable and certain. While due to the intermittence and randomness of new energy resources, the output of new energy generator is uncertain, traditional power flow calculation cannot deal with this kind of uncertain power flow problem, thus type-II fuzzy logic forecasting and interval arithmetic are applied to solve this uncertain problem in the paper. Type-II fuzzy logic forecasting is used to get the output of generator in a mathematical sense that the uncertain variables can be express as an interval form, then interval arithmetic is applied to calculate power flow. As one of interval arithmetic, Krawczyk-Moore method is applied in power flow calculation in this paper, which convergence does not need to get inverse of interval matrix, and the initial interval obtained by type-II fuzzy logic can improve the problems of early convergence, slow convergence and no convergence which are drawbacks of interval arithmetic. The Algorithm is tested on IEEE 30-bus system to validate the applicability.