1000kV与500kV交流线路同塔架设相间放电特性及绝缘配合

Flashover Characteristics and Insulation Coordination of Phase-to-phase Air-gaps for AC Transmission Line With 1 000 kV Double-circuit and 500 kV Double-circuit on the Same Tower

为确保1000kV与500kV同塔架设相间绝缘设计的可靠性和经济性,采用2套长波前冲击电压发生装置产生不同波前时间冲击电压模拟线路相间过电压,针对中国1 000 kV双回特高压线路与500 kV双回超高压线路同塔架设的杆塔结构及导线布置特点,开展了上侧1000kV相间操作冲击放电试验、下侧500 kV相间操作冲击放电试验,以及1000kV与500 kV相间的空气间隙放电试验研究,获得了不同间隙距离放电特性曲线和对地高度影响等研究结果。并根据中国华东地区拟采用该输电方式的苏州—沪西段工程相间过电压水平,分析提出了相间绝缘间隙配置推荐值。研究表明8分裂导线相间1000 s操作冲击放电电压平均间隙系数K为1.61,8分裂—4分裂和4分裂-4分裂相间标准操作冲击放电电压平均间隙系数分别为1.44和1.49。该研究成果为国际上首次提出的特高压与超高压同塔架设输电方式提供了外绝缘设计依据。

In order to ensure the reliability and economy of phase-to-phase air-gaps design,in this paper,based on the tower structure and conductor arrangement of the transmission line with 1 000 kV double-circuit and 500 kV double-circuit on the same tower,phase-to-phase air-gaps flashover tests were carried out.The air-gaps tests include 1 000 kV conductor to 1 000 kV conductor,1000 kV conductor to 500 kV conductor,and 500 kV conductor to 500 kV conductor.Different wave-front impulse voltage was generated with two long-front impulse voltage generators to simulate phase-to-phase switching over-voltage surge of the transmission line.By different conductor structure and different wave-front time tests,a large number of test data and several important flashover characteristics curves were obtained.According to the phase-to-phase over-voltage level of one planning UHVAC power project——-Suzhou-to-Huxi transmission line in East China,the phase-to-phase insulation gaps were analyzed and given out.Results show that average gap factor K of 8-subconductor bundle phase-to-phase flashover voltage under 1 000 ？s long-front switching impulse is 1.61,and K of 8-subconductor bundle to 4-subconductor bundle and 4-subconductor bundle to 4-subconductor bundle under standard switching impulse are respectively 1.44 and 1.49.It provides external insulation design basis for the power transmission mode with ultra high voltage（UHV） and extra high voltage（EHV） lines on the same tower,first presented to the international.