一种降低10～35kV架空线路雷击断线率的方法研究

Study on Method for Reducing Rate of Disconnection of 10-35 kV Overhead Line Caused by Lightning Stroke

原有的防止雷击断线事故方法是转移工频电弧,使导线不受电弧直接灼烧。然而,如果工频电弧不熄灭,流过闪络点的短路电流依旧会对导线造成伤害,多次雷击的累积效果会减短导线使用寿命。为此,提出了一种通过快速熄灭工频电弧来保证导线正常使用寿命从而达到降低导线断线率的方法,基于此方法研制出爆炸灭弧防雷间隙装置。通过绝缘配合试验、触发响应时间测试和工频电弧灭弧试验,结果证明该装置既能定位雷电冲击放电路径,又能熄灭雷电击穿后空气保护间隙工频电弧,使空气保护间隙电弧存在时间非常短(仅为3 ms),对导线及绝缘子串的影响甚微,确保绝缘子和导线的正常使用寿命。

Original method to prevent disconnection accident caused by lightning stroke is to transfer power frequency elec- tric arc which may not result in direct firing of conductor. However, if the power frequency electric arc is not extinguished, the short-circuit current flowing past the flashover point will do harm to conductor and several times of lightning stroke will reduce service life of conductor. Thus, this paper proposes one method for ensuring normal service life of conductor by rap- idly extinguishing power frequency electric arc in order to reduce rate of disconnection of the conductor. On the basis of this method, it develops an explosion arcing lightning protection clearance device. By insulation coordination test, trigger re- sponse time testing and power frequency electric arcing test, it verifies that this device is able to positioning discharge route of lightning impulse and extinguish power frequency electric arc of air protection gap after lightning stroke which may reduce existing time of air protection gap electric arc（only to be 3 ms） and ensure normal service life of insulator and conductor for reason of small affection on conductor and insulator chain.