Design Of Single-phase Dynamic Voltage Restorer

Along with the development of modern technology, power customers have more and more severely requests of power quality. But recent years, after the widely use of power electronics equipment and influence of special loads such as electric arc stove and electrized railroad, the pollution in power system became much serious than before. So improve and control power quality was became an important task for modern power system. In this case, a new technology known as Custom Power come forth and become the most important and effective method for improve power quality at present.The meaning of Custom Power is using modern power electronics technologies to realize the control of power quality and the serve of special power for customers. The Dynamic Voltage Restorer (DVR) designed in this paper was one of the most important of Custom Power. This equipment can compensate the sags or counteract the swells of power system voltage through the special voltage produced by itself, so it can overcome the bad influence imposed on customers which comes from the fluctuate of power system voltage. The DVR has been studied from last 90s' overseas and making use of it now, but we are studying it yet.This paper made detailed analysis and explain of the most familiar power quality problem—the sags in power system firstly, then introduced the configuration and principle of DVR and design a simple DVR device based on the conditions in exciting. From the results of computer simulate and experiment, we can see that the device although has some shortages in dynamic response speed and compensate precision, but it illuminated the mechanism of DVR and embodied its application value sufficiently yet. If more improvement of its control system being done, it should become a product with high practical value.