Unsymmetrical short-circuit analysis for distribution system considering loads

• A method for short-circuit study of distribution system considering loads.
• The method is applicable to radial as well as meshed distributions systems.
• The method is capable of handling multiple faults.
• The results compare extremely well with PSCAD/EMTDC simulations.

Short circuit analysis is an essential tool for determining the short-circuit-current rating of the protective devices and different substation equipments to be installed in a distribution system as well as for co-ordination of the protective devices. Usually, the effect of load is neglected during short-circuit analysis, which introduces inaccuracy in the calculated values of short-circuit current. To address this issue, this paper proposes an efficient and accurate short-circuit fault analysis method for balanced and unbalanced distribution system considering the effect of loads. Comparison of the results obtained by the proposed method with those obtained by time-domain simulation using PSCAD/EMTDC establishes the accuracy of the proposed method.