COMPARITIVE STUDY OF A GRID CONNECTED WIND-PV SYSTEM FED INTER-LINE DVR USING DIFFERENT CONTROLLERS TO MITIGATE VOLTAGE SAG

Voltage interruptions often in the form of voltage sags lead to severe power quality problems in the Distributed Generation (DG) which causes economical loss. Various methods such as DVR, DSTATCOM & UPQC has been already proposed to improve the power quality. Interline DVR is one of the method to improve the PQ problem. In this method, two DVRs with a common DC link is used. The advantage of this type is one DVR is used to compensate the voltage sag while the other DVR helps in maintaining the DC-Link voltage by giving the required active power to the DC bus. Many control methods are already proposed to solve the voltage sag problem. These methods include PI, Fuzzy, Fuzzy-PI, SVPWM & ANN controllers. In this proposed research work, all the controllers are designed and compared with each other in order to propose the best controller to mitigate the voltage sag having good accuracy and best harmonic reduction.