An Effective Methodology for Short-Circuit Calculation of Power Systems Dominated by Power Electronics Converters Considering Unbalanced Voltage Conditions and Converter Limits

This paper deals with the challenge of short-circuit calculation for power systems dominated by power electronics converters. A novel methodology has been presented to identify short-circuit equilibrium point of the studied system considering the operation and limitations of power converters. The studied system has been modeled with an element-based steady-state formulation. In particular, the governing equations implemented on converter control, which involve a specific control mode and various potential current-saturation states, are included. Then, an effective and efficient approach has been proposed to identify the short-circuit equilibrium points that satisfies converters limitations. Numerical case studies with VSCs show that the proposed methodology can identify the short-circuit equilibrium point efficiently and accurately with different types and depths of short-circuit fault. The short-circuit calculation results have been validated with dynamic simulations.