Study On Local Protection Of 220 KV Substation In Alpine Region

Relay protection is indispensable in power system,and the development level of relay protection in China is advanced internationally.Status With the rapid development of UHV AC/DC transmission technology,there are many different characteristics in the development process of power grid characteristics,which put forward higher requirements for relay protection control.From the current situation,relay protection still has some problems,such as old interface form,reduced system reliability,poor personnel carrying capacity,and high equipment energy consumption,which have seriously affected the stability and progress of China’s power system.Therefore,local relay protection relies on new technologies to reduce intermediate links during protection,enhance the effectiveness of protection actions,and enhance the technical ability of relay protection operation control.In recent years,State Grid Corporation has put forward the principle of "four characteristics"(sensitivity,reliability,selectivity and quickness)of relay protection after comprehensive consideration,and steadily promoted the research on local relay protection.The practical application of local protection devices in substations is analyzed in depth,for electromagnetic environment,grounding,security protection and other aspects of the local protection device interference,the related technical implementation is proposed to select the in-situ protection device.The power distribution and climate characteristics in Mohe area are analyzed,and the local protection design is carried out according to the actual circuit situation on site,so as to verify the reliability of unprotected local protection in outdoor operation environment,and explore and pilot the installation mode of local protection in outdoor substations.With less configuration,less setting and less maintenance,the local protection device can well adapt to the cold characteristics in Northeast China.Finally,the single-phase short-circuit fault is simulated through the field test and debugging of the local protection device,and the corresponding waveform is obtained,and the local protection trips.In this way,the local protection can better meet the practical application in alpine regions,and provide effective reference and guidance for subsequent engineering construction.