Sparsity Based Short Circuit Analysis of Power Distribution Systems with Inverter Interfaced Distributed Generators

This paper proposes a method for calculating short-circuit current in distribution systems with inverter interfaced distributed generators (IIDG). It is capable of calculating the short circuit in a multi-phase distribution systems based on the symmetrical components without obtaining the complete impedance matrix. Furthermore, it considers the load effect and the pre-fault state of the system for the fault analysis and is able to handle unbalanced systems with mutually coupled phases. The problem is formulated as an iterative linear system calculation and is solved by generalized minimal residual (GMRES) approach. The validity of the proposed algorithm is verified through the simulation of IEEE 13-node, 123-node, 478-node, 954-node, and 1430-node distribution systems. Simulation results demonstrate the effectiveness of the proposed algorithm and the advantages of using the GMRES method to calculate the short circuit current in a distribution system with IIDG.