330kV和750kV地线导弧间隙放电和灭弧性能研究

由于地线导弧间隙在运行中存在放电分散性大,灭弧能力随机性强等问题,为了优化和改善330 kV和750 kV输电线路架空地线导弧间隙的放电特性和灭弧性能,对目前工程上使用的不同类型的地线导弧间隙进行了工频放电电压特性、雷电冲击伏秒特性和操作冲击伏秒特性试验以及灭弧性能试验研究。结果表明,在330 kV和750 kV系统中使用的间隙距离下,导弧间隙满足在工频过电压和操作过电压下不放电而在雷电过电压下可靠放电的要求;灭弧性能试验表明电流幅值过小或过大均会使导弧间隙灭弧时间变长,重燃率增加。综合考虑放电和灭弧特性,实际运行中建议优先选择悬垂式导弧间隙。

Research on Discharge and Arc Extinguishing Characteristics of 330 kV and 750 kV Overhead Ground Wire Arc-Guiding Gap

Because the arc-guiding gap has large discharge dispersion and random arc extinguishing ability in operation,to optimize and improve the discharge and arc extinguishing characteristic of 330 kV and 750 kV overhead ground wire arc-guiding gap,the test of discharge characteristic of power-frequency voltage,the voltage-time characteristic of lightning impulse and switching impulse and arc extinguishing characteristic are conducted.The results show that the arc guiding gap won't discharge under power-frequency overvoltage and switching overvoltage but discharge under lightning over-voltage,this meets the requirements under the gap distance used in 330 kV and 750 kV power system;arc extinguishing characteristic test shows that too large or too small current amplitude will cause longer arc extinguishing time and more arc reignition probability.Considering the results of discharge and arc extinguishing test,we suggest that preference to suspension arc-guiding gap in the actual operation.