Performance Assessment of Photovoltaic Predicated Dynamic Voltage Restorer Using PI and Fuzzy Logic Controller

In this paper, a photovoltaic based dynamic voltage restorer (DVR) is proposed to compensate voltage sag using a fuzzy logic controller. It also operates as an uninterruptable power supply (UPS) when the utility grid fails to supply. It also reduces the usage of utility power. A high step up DC-DC converter with high voltage gain is used which reduces the size of the series injection transformer and also reduces the number of batteries used. The fuzzy logic controller takes the two inputs, error and change in error maintains the load voltage by detecting voltage variations using dq transformation technique. The PI controller utilizes the error signal from the comparator to trigger the switches of an inverter using a sinusoidal PWM scheme. Simulation results prove the ability of the proposed DVR to mitigate the voltage sag.