A Short‐Circuit Current Calculation Method for Two‐Point Dissimilar‐Phase Single‐Phase‐to‐Ground Faults in Active Distribution Networks Based on the BFGS Algorithm

ABSTRACT For active distribution networks with high penetration of distributed photovoltaic (PV) systems, research on short‐circuit current calculation methods primarily focuses on single‐point fault scenarios. However, studies addressing short‐circuit calculations for two‐point dissimilar‐phase single‐phase‐to‐ground faults remain limited. This paper proposes a steady‐state short‐circuit current calculation method for such faults in active distribution networks, based on the Broyden–Fletcher–Goldfarb–Shanno (BFGS) algorithm. By employing a general equivalent fault model of a distributed PV unit and constructing the fault sequence networks corresponding to two‐point dissimilar‐phase single‐phase‐to‐ground faults, a system of equations is formulated using the sequence voltage vector at nodes as the unknown variable. A detailed solution approach utilizing the BFGS algorithm is then presented. The accuracy and effectiveness of the proposed method are validated through case studies and simulations conducted in PSCAD/EMTDC.