Abstract:
With extensive applications of renewable energy, the power quality issue is becoming complex with a lot of uncertain factors, such as the geographical unbalance of power grid and load fluctuations, then the requirement for solving voltage sag become urgent. When the grid voltage sag occurs, a dynamic voltage restorer (DVR) acts rapidly for compensation so as to maintain the load voltage. This paper mentions current research status of DVR at home and abroad, and introduces various voltage sag detection algorithms, compensation strategies, dynamic tracking methods and the system control strategies of DVR. With detail analyse and comparison, this part gives the guidance to the subsequent research work.