Dynamic Voltage Stability Improvement by Reactive Power Adjustment of Virtual Synchronous Generator in Remote Island Power Systems

Renewable energies are difficult to apply in remote island power systems due to their intermittency. Load fluctuations due to the intermittency of renewable energy cause fast voltage collapse. This paper proposes the improvement of dynamic voltage stability by adjusting the reactive power of a virtual synchronous generator. The reference values of active and reactive power of the virtual synchronous generator are determined by the droop characteristics of frequency and voltage, respectively. Simulation verification is performed by changing the gain of the voltage and adjusting the amount of reactive power injected. The simulation results show the relationship between the droop gain and the dynamic voltage stability. Critical boundary index is used as the dynamic voltage stability index.