Dynamic Equivalent Representation For Symmetrical Short-Circuit Analysis of Power Systems With Power Electronics

Thévenin equivalent has been considered the standard power system representation for short-circuit analysis. However, the increasing penetration of power electronics in modern power systems introduces diversified short-circuit current responses which are not considered by conventional Thévenin equivalent. As an alternative, this paper proposes a different dynamic grid equivalent representation for short-circuit analysis of power systems with power electronics. The equivalent parameters are identified to accurately capture the dynamic short-circuit current responses contributed by power converters. Also, the equivalent parameters are varied from different depths of short-circuit fault in order to various fault conditions. The proposed grid equivalent has been tested and validated on studied systems with Voltage Source Converters (VSCs).