Research On The Centralized Energy Storage Dynamic Voltage Restorer

Dynamic voltage restorer (DVR) is a important instrument for stabilize power quality on sensitive elements, it can compensate voltage sag rapidly and stabilize voltage waves. Normal single DVR has some shortage such as: utility ratio is low, poor economic operation and compensation time is short. The intre -line dynamic voltage restorer (IDVR) cannot sustain the circumstance that both line were lack of voltage such as: smooth switch in micro-grid. A structure of an centralized energy storage dynamic voltage restorer is presented in this paper.The centralized energy storage dynamic voltage restorer can recover the problem of voltage sag better and longer in one feeder, and can realize the function of voltage drop problem in multiple feeder.Firstly, based on the fundamental principle of normal dynamic voltage restorer and the intre -line dynamic voltage restorer, the centralized energy storage dynamic voltage restorer is presented,in which energy storage batteries was connected to DVR structures in different feeder.Analyzing fundamental principle and the energy flow in it.Secondly, found the mathematical model of the centralized energy storage dynamic voltage restorer and analyzed the parameters within it. Based on the method of "abc-dq"transaction, PI controller was used in the centralized energy storage dynamic voltage restorer with the signal of voltage feedback. Figure out a improvement measure of fault criterion in the detection by monitoring accessible node voltages of d-axis and q-axis, which can detect the voltage sag rapidly.Thirdly, found the simulation model of the centralized energy storage dynamic voltage restorer. When voltage sag is occurred in single feeder, the centralized energy storage dynamic voltage restorer can great improve the compensation effect and the compensation time. When the voltage sag is occurred in mult- feeder, the influences of compensation effects is little with different power of loads and different voltage sag on different feeder.Consider of the reality situation, the longest distance of compensation from the centralized energy storage dynamic voltage restorer to loads was fited in different circumstances.Finally, the centralized energy storage dynamic voltage restorer can recover the problem of voltage sag better and longer in one feeder, and can realize the function of voltage drop problem in multiple feeder.