Research Of DVR In Microgrid Seamless Transfer

With the energy and environment problems becomes increasingly prominent and thedevelopment of distributed power generation technology,Microgrid,which takes a part togetherwith the power grid, is the most effective way to utilize the distributed power supply,in whichseamless transfer between grid and islanding mode of Microgrid is one of the most importantresearch in microgrid that aims to ensure the uninterruptible power supply for sensitive load anddistributed generation.The paper mainly concerns about the power quality problem of microgrid. The applicationof non-series transformer dynamic voltage restorer in the microgrid has been studied.With thestructure and control strategy improved, no phase jump minimal energy control strategy isrealized,and also the operation pattern seamless transfer process between grid and islandingmode is realized. The main works are as follows:1) An advanced DVR topology is presented, deducing the relative formula of the minimumenergy control strategy in detailed,and the advanced minimum energy control strategy isproposed.The MATLAB simulation model is established and the four different cases verifyimproved minimum energy control strategy; at the same time, it compare with the traditionalminimum energy control strategy.2) DVR is introduced into microgrid to realize seamless transfer process. Based on the windgenerator, solar and battery distributed generation module modeling,the model of microgridsystem containing DVR is built.The the operation characteristics of distributed generation andsensitive load in the the three states,island mode、island to grid-connected and grid-connectedto island are analysised.3) A low-power transformerless DVR prototype is accomplished and the main circuit andcontrol system are designed. Through the C8051single-chip implementation of the proposedcontrol algorithm proves the feasibility of the scheme.The introduction of the DVR into microgrid cooperates to realize seamless transfer processresearch. It can draw conclusions as follows:1) Advanced minimum energy control strategy cannot only maintains the sensitive load voltage amplitude and phase continuity, also can reducesenergy consumption;2) Introduceing the DVR into seamless transfer process can greatly enhancethe sensitive load power quality level, which has the broad application prospect.