Title:  Application of Inverse-Time Overcurrent Protection Based on Low Voltage Acceleration in Micro-Grid
作者:  李永麗; 金 強(qiáng); 李博通; 李中洲  天津大學(xué)智能電網(wǎng)教育部重點(diǎn)實(shí)驗(yàn)室，天津 300072
Author(s):  LI Yong-li; JIN Qiang; LI Bo-tong; LI Zhong-zhou
 Key Laboratory of Smart Grid of Ministry of Education，Tianjin University，Tianjin 300072，China
關(guān)鍵詞:  ; 分布式電源; 微電網(wǎng); 低電壓加速反時(shí)限過(guò)電流保護(hù); 運(yùn)行模式
Keywords:  ; distributed generator; micro-grid; inverse-time overcurrent protection based on low voltage accel-eration; operation mode
分類(lèi)號(hào): TM773
文獻(xiàn)標(biāo)識(shí)碼: A
摘要:  低壓配網(wǎng)中用的反時(shí)限過(guò)電流保護(hù)(ITOC)由于分布式電源(DG)的接入及微電網(wǎng)運(yùn)行方式變化的特殊性從而不能滿足選擇性和速動(dòng)性的要求．為此，基于分布式電源和微電網(wǎng)的運(yùn)行及故障特征，提出了一種無(wú)需借助通訊的低電壓加速反時(shí)限過(guò)電流保護(hù)(UAITOC)方案．該方案保證了線路出口處故障時(shí)保護(hù)能快速動(dòng)作，并且適用于微電網(wǎng)并網(wǎng)和孤島2種運(yùn)行狀態(tài)，無(wú)需切換保護(hù)定值就可以滿足選擇性和速動(dòng)性的要求．同時(shí)該方案通過(guò)Digsilent軟件仿真驗(yàn)證了所提保護(hù)原理的正確性．
Abstract:  Traditional inverse-time overcurrent protection(ITOC)may not satisfy the requirement of selectivity and speed because of distributed generators’(DG)connection to grid and special variable operation modes in some condi-tions. The operation characteristics of DGs and micro-grid were considered here and a new protection scheme of in-verse-time overcurrent protection based on low voltage acceleration(UAITOC)was proposed. The new protection scheme，which does not need the use of communications can satisfy selectivity and improve action speed in all condi-tions without changing the settings of protections. It makes protective relays act instantaneously when fault occurs at line exit end. Simulation by Digsilent shows the protection principle is correct and feasible.