Analysis and Modeling of Inverter based Distributed Storage Considering Short Circuit Characteristic

More and more energy storage equipment have been in operating to satisfy the daily difference of peak-valley load. Contrast to the electric mechanical based traditional power source, the short-circuit current out of ES (energy storage) inverter is quite different during fault period. The steady-fault model is always used for analysis but lack of sufficient accuracy. The control strategy of ES inverter considering low voltage ride-through state is analyzed in this paper, and a fault simulation platform is also founded. Three key factors have evident impact on transient short-circuit output are analyzed and compared, then a non-mechanism model structure determined by voltage drop is proposed. The segment strategy is adopted for short-circuit current modeling according to different level of voltage drop, and an optimized algorithm is designed for parameter identification. Finally, the correctness and accuracy of the new model is verified by simulation comparison.