Fault Analysis for Distribution Networks With Current-Controlled Three-Phase Inverter-Interfaced Distributed Generators

The fault current of a three-phase inverter-interfaced distributed generator (IIDG) depends on the control strategy employed during grid faults. A new short-circuit current calculation method for IIDGs is developed in this study according to the current control and reactive power support during the low-voltage ride-through operation period. To investigate how the ride-through time relates to the short-circuit current of IIDGs, short-circuit responses under different fault conditions are compared. The short-circuit current of a multi-IIDG distribution network is determined with the proposed technique to consider ride-through time and sequence current control. The correctness of the proposed method is verified by simulation.