500kV高海拔紧凑型输电线外绝缘特性及绝缘配合

External Insulation Characteristic and Insulation Co-ordination for 500 kV High Altitude Compact AC Transmission Line

为了获得德宏—墨江交流500kV单回紧凑型输电线路杆塔间隙的放电特性参数,为工程设计提供依据,针对该工程塔型及金具特点,采用模拟真型杆塔试验研究方法,开展了边相及中相V串导体对杆塔间隙的标准操作冲击、长波前操作冲击(波前500μs、1000μs)和标准雷电冲击电压放电特性试验研究,获得了多条50%放电电压特性曲线及不同波前时间操作冲击放电电压的差异。根据试验及过电压计算结果,推荐海拔2500m、3000m下相地最小绝缘间隙分别取4.2m和4.3m。

In order to get the air gap characteristic parameters of tower for the Dehong-Mojiang 500kV AC compact transmission line, by simulation-tower test method ,and on the basis of the tower and conductor bundle configuration of the first 500 kV high altitude （the highest region is at an altitude of 3000 m） transmission ＆ transformation project, in Yunnan province, we studied the standard switching impulse voltage, long wave-front（500 μs, 1000 μs）switching impulse voltage and standard lightning impulse voltage flashover characteristic of side and middle phase insulation gap between the ＇V＇ string conductor to tower. Several important air gap flashover characteristic curves have been got. The insulation co-ordination problem is analyzed from the test and the overvoltage simulation results. Results show that the design values 05 insulation gap are respectively 4.2 m and 4. 3 m, at the altitude of 2500 m and 3000 m. Under the premise of enough external insulation safety in operation, the conclusion optimizes the tower design and reduces the project cost.