The Mechanism of Synchronous Condenser in Voltage Sag Mitigation During FRT of Renewable Energy Integrated Systems

With the large-scale integration of renewable energy, the application of power electronic converters in power systems has become increasingly widespread. Renewable energy units, constrained by short-circuit current limits, provide insufficient voltage support during fault ride-through (FRT) periods, resulting in severe system voltage sags. Synchronous condenser (SC), offering dynamic reactive power support, can mitigate system voltage sags during faults. This paper first analyzes the relationship between voltage sag propagation and electrical distance within the system. It then derives the relationship between the voltage support effectiveness of SC and factors such as electrical distance to the node and the condenser's capacity. Finally, simulation experiments are conducted to validate the proposed voltage sag propagation patterns and the mechanism by which SC mitigate system voltage sags.