Study on the dynamic voltage restorer use in an isolated power supply system

It´s gain widely application for independence-net power supply system in oil drilling field, ships, standby power station of a factory and outside working etc. As the limit of generate electrical capacity, the power quality can easily effects by nonline load in power-line. This paper presents a voltage quality controller with use of active control method, and make full consider for the problems which maybe happen in independence-net power supply system such as harmonics, sags, short time out-supply and frequency change etc. A soft phase-lock technology based on instantaneous reactive power theory was suggested to solve the synchronization, phase-lock, voltage´s breadth value make constant and frequency change etc. and also discussed the harmonics definition, calculating method on situation of frequency change. At the end, it give the simulation and experimental results to support the viewpoint of auctorial.