Application of Distribution Static Compensator (D-STATCOM) to Voltage Sag Mitigation

This paper presents a study of a D-STATCOM (Distribution Static Compensator) used for mitigating voltage sag. The basic idea of the voltage sag mitigation, using a D-STATCOM is to dynamically inject a current of desired amplitude, frequency and phase into the grid line. The proposed method extracts the active and reactive parts of the positive- and negative-sequence component for generating reference values of current that need to be injected into the point of connection D-STATCOM in order to compensate the voltage errors. The proposed method offers structural simplicity and less calculation complexity. Simulation results indicate that this method is effective and D-STATCOM has good performance to mitigate the voltage sag.