Development & Application Of Long Wave Front Switching Impulse Joint Test Device

The air gap distance is basic data for design UHV（Ultra-high voltage）substation and transmission line in UHV project，it affects safety and economy ofUHV project.For did not pay enough attention and lack of test condition，phase-to-phase tests were carry out very little in domestic and international，onlyconfined short wave front switching impulse phase-to-phase test.The front time ofswitching impulse wave is up to 1000μs and above in 1000kV UHV AC transmissionline，using long wave front impulse wave do phase-to-phase test consistent with actualsituation of UHV transmission system.This project supported by 1000kV UHV AC power transmission key technologyresearch program of SGCC（State Grid Corporation of China）.The main work of thisthesis is developed long wave front switching impulse joint test device，and applied itto UHV substation and transmission line phase-to-phase air gap joint test in order totest it’s test ability.This article research the following aspects:①develop 7500kV impulse voltagegenerator which can produce 1000/5000μs long wave front switching impulse，research it’s circuit，develop key components and develop impulse voltage divider，and test it’s performance；②improve 4800kV impulse voltage generator which adoptconventional loop，make it can produce 1000/5000μs long wave front switchingimpulse，put forward improved scheme based on the difficulty conventional impulsevoltage generator produce long wave front switching impulse，some improvedschemes are analyzed and then choice the best improvement scheme to improve4800kV impulse voltage generator，debugging synchronization performance of4800kV impulse voltage generator at long wave front switching impulse；③combined7500kV impulse voltage generator with 4800kV impulse voltage generator front longwave front switching impulse unit test device，using electronic adjustable time delaydevice, makes the 7500kV impulse voltage generator and 4800kV impulse voltagegenerator produce combined voltage in line with national standards，then checkout thedevice with test；④formulation phase-to-phase test procedures basis of nationalstandards，discuss data correction method，develop account test data program andatmospheric correction software；⑤do phase-to-phase test use typical electrode witchused in UHV substation and UHV AC transmission line in order to test the device’stest capability. Long wave front switching impulse wave joint test device，resolve the problem oflack of joint test device conditions when do phase-to-phase test in China，will greatlyenhance China’s UHV external insulation of air gap test ability, test results will bebasic data for design air gap for China’s UHV project.