Simulation Of The Series Compensated Power Grid And Study On UHV Transmission Line Protection

With the development of huge electric power grid in China, more and more seriescompensation devices are applied in the grid. The WeiXiang series compensated system inDafang Transmission Line, the SanBao series compensated system, the Feng-Wan-Shunseries compensation line and the PingGuo Series compensated system in TianPingtransmission line are all applied cases in our country's power grid. It is estimated that therewill be 1000~1200 kVar series compensation devices to be applied in the country's grid in2005. So, it is very important to perform studies on the protective relay of the seriescompensated system and it is also the primary developing direction of the ultra high voltagetransmission line protection. Digitial simulation is the important studying method on the protective relay. Now, theoff-line anaysis method is often used. But when this method is applied on the protectionstudy of the series compensated line, some obvious disadvantages are taken on, it can'tconsider the effect of the protection system for series compensated device. To avoid it, thedissertation builds the simulation platform with the transient, close-loop and quasi-realtime characteraccording to the demand of actual engineering project. This platform integrates the model of power grid,protection system for series compesantion device, essential control function of the seriescompensated device and protective relay of the transmission line,it can realize the exchangeoperation, provide good human machine interface and can fulfill the engineering demand ofthe study on series compensation line protection. The TianPing parallel transmission lines are the important lines in the China south gridand they are equipped with series compensation system of SIMENSE. Base on the abovework, and according to the given engineering project, the dissertation analysises the character ofthe protective relay, gets the engineering results and presents some operation advice. Besides discussing the protective relay of the series compensated line, the dissertationalso performs the research on the theory and realization technology of the ultra high voltagetransmission line protection. The phase-selection component is the main function of the protection system. Aftercombining the simulation datas and dynamic test result, the dissertation points out that thereexists some errors in the universal phase-selection scheme in the special cases, at the sametime, gives the new scheme based on muti-criterions. Dynamic test shows that the new IIIscheme improves the character in the reliability and applicability. By researching on the fault component distance relay, the dissertation presnts a seriesof new distance relay based on the fault component. By the in-depth study and analysis,how to accelerate the trip and get new type of relay are discussed. The dissertation performs the research on making of new UHV transmission protectionbased on new technology demand. It analysis some correlative technology problems suchas the scheme design,software realization and the dynamic test method ect, at the same time,manafactures the new generation protective device. Now, the device has been passed thecheck of the experts and is test-operating in the XuGuan 220 kV line of Hubei power grid. At last, the dissertation gives the systematical summarize and points out the furtherwork.