Z source inverter based dynamic voltage restorer using super capacitor to mitigate voltage SAG and voltage swell

This paper uses super capacitor as the energy storage device for the DVR to compensate voltage sag, voltage swell and harmonics due to addition of nonlinear load in the distribution line. Based on this topology, DVR consist of super capacitor, z source inverter and injection transformer. Super capacitor produces the necessary dc voltage which is given as the input voltage to the z-source inverter; provide the necessary injecting voltage, which has to be restored. In addition, it also consists of PI controller which provides the necessary control signals for the z source inverter. The simulation results of the proposed DVR system are demonstrated.