Voltage sag and swell mitigation using D-STATCOM in renewable energy based distributed generation systems

Renewable distributed generation systems are an alternative solution to provide energy locally near customers. However, the supplying of power without disturbance is the main challenge for utilities, especially for systems that integrate fluctuating renewable sources which can cause voltage sag and swell. In this paper, voltage sag and swell issues are investigated. The first studied scenario is related to the disturbance of the energy source and the second one is due to the installation of a heavy load with a sensitive load at the same supplying bus. A D-STATCOM is connected at the point of common coupling (PCC) to mitigate the voltage sag and sell problems. An energy storage battery has been installed at the DC-side of the compensator that gives the possibility to control the voltage at the PCC and exchange the active and reactive power with the grid. A linear proportional integral (PI) feed-forward controller supervises the compensator. The obtained results show that the D-STATCOM compensator behaves as a good solution to mitigate the voltage sag and swell in distribution grid.