Computational Models of Short-Circuit Faults in the Grid Dominated by Inverter-Based Resources

As the inverter-based resources (IBRs) access ratio continues to increase, the fault characteristics of the power grid is dominated by IBRs, and the fault equivalence model of short circuit current encounters difficulties in the scenario where the power grid dominated by inverter-based resources. In this paper, the short-circuit current calculation problem of the grid dominated by inverter-based resources is studied. The typical low voltage ride through (LVRT) control strategy of IBRs under the master-slave control strategy is analyzed, and the fault equivalent model of V/F-controlled inverter-based resource is obtained. Secondly, taking into account the characteristics of the island operation of the inverter-based resource, the short-circuit current calculation equations of the island operation mode of the inverter-based resource are constructed. Finally, based on the IEEE33 example model, the accuracy of the proposed equivalent model is verified.