Multi-source Collaborative Short-circuit Current Calculation Method

With the advancement of the "Double Carbon" strategy, China's power system is undergoing a transformation from a traditional AC power grid dominated by synchronous machines to a heterogeneous multi - source system with a high proportion of new energy and hybrid AC - DC grids. The coupling of the randomness of new energy and the weak inertia characteristics of power electronic devices leads to significant heterogeneity in the spatial - temporal distribution of short circuit current. Traditional symmetrical component methods and ideal power supply assumptions are difficult to accurately represent the multi - source fault response mechanism, resulting in protection setting mismatches and equipment redundancy problems. This paper proposes a short - circuit current constraint representation method based on the "power flow" mode for the scenario of metallic three - phase short - circuit. By constructing refined models of new energy sources, DC converter stations, and combining with the pre - fault power flow to correct the initial conditions of the power supply, the differential contributions of heterogeneous multi - sources to the short circuit current amplitude are quantified. This research provides a theoretical basis and technical path for short - circuit current control in new - type power systems.