Study On Over-voltage And Their Protection Measures For 200kV Fuxing-Gaijiaping Transmission Line In Dazhou

This thesis built the models computing the working frequencyover-voltage' operation over-voltage fOr 220kV Fugai transmissionline,calculates and analyzes working frequency over-voltage' operationover-voltage using EMTP program and provides reasonable protectionmeasures for the transmission line. Furthermore, Regulations method,traveling wave method and striking distance method are used to study andcompare lightning-enduring capabilities of different types of pole in powertransmission lines aiming at the fact that the lightning strike switching rate of220kV Fugai line is higher. Various factors that influence lightning strikeswitching rate are also analyzed. It has been showed that fOr some givenconfiguration,all lightning over-voltages on substation equipments do notexceed the 1ightning strike insulation level in the case of invading waves outof lightning strike aerial input protection line. The arrester position is feasibleThe back-strike switching rate caIculated by traveling wave method is moreserious than that by regu1ation method in the analysis of line strike backlightning-enduring capabilities. lt is more effective to reduce the strike backswitching rate by decreasing resistance of impulsion grounding resistor ofpole than by increasing number of insulators. The round-strike switching ratecalculated by strike distance method is more serious than that by regulationsmethod. The back-strike by straight-strike is more serious than that byback-strike. some influences are associated with pole types among witch Z5have the biggest effect on lightning strike switching rate of lines and ZM22Ahas the sma11est effect on round-strike switching rate These results willpropose theoretical basis to enhance the operation reliability fOr 220 kV Fugaitransmission line...