A new method for analyzing unsymmetrical faults under data uncertainties

Fault analysis uses a given set of data regarding generation plants and line branches. The main objective is to calculate voltages and currents considering the type and the location associated with a specific fault. As the input data are imprecise, this paper incorporates the interval mathematics into fault analysis problem in order to take into account data uncertainties. Therefore, this paper proposes a new method for modeling an interval analysis for unsymmetrical faults. Single line-to-ground and line-to-line faults are investigated. The corresponding fault analysis equations are written in terms of voltage expressed in rectangular coordinates, and the iterative solving process for the resulting linear system of interval equations uses Krawczyk method. The proposed method is implemented in Matlab environment using Intlab toolbox. Results yielded by the proposed method are compared with those ones yielded by the Monte Carlo Simulation. The 14-bus and 1768-bus test systems are used.