Research On Dynamic Voltage Restorer

The requirement on electrical power quality is ever increasing along with the development of technology. Voltage sage is the most frequently happening problem on power system and might cause great economic loss. To solve this problem, Dynamic Voltage Restorer (DVR) is the most efficient and economic device at present. In this dissertation, based on the analysis of theory on DVR and its elements, a Detecting method and voltage compensation strategy for DVR were proposed, and proved through simulation.The elements of DVR device was introduced in detail, different main circuit topology were compared to find their effect on DVR's performance. This thesis also did some work on the control strategy of DVR, and have completed the design scheme finally.Different arithmetic methods on voltage sag Detection were compared. Based on transient reactive power theory, an improved virtual three phase method was proposed to test three phase imbalance voltage sag. The simulating results has proved that the method is exactly and promptly.Analyzed different compensating strategy's compensating theory, advantage and disadvantage, and proposed a new compensating strategy by calculate the best compensation point based on the existing strategies. Then this paper proved that the new compensating strategy has evidently enhanced the general capability of DVR by the simulation. Combined with virtual three phase test method, the DVR demonstrated improvement on its performance through simulation.