固相爆炸纵吹气流条件下熄弧特性及抑制电弧重燃的机理研究

运用固相爆炸气流主动截断电弧是一种新型的防雷措施。这种措施是利用雷电诱导触发固相爆炸产生高速、高压纵吹气流作用于电弧萌芽的极早脆弱期,对电弧实行"以快制强"的熄灭机制。电弧熄灭后持续的气流将继续作用于雷电通道对电弧重燃实现深度抑制。建立爆炸气流及气流耦合电弧模型,得出电弧熄灭判据。运用介质恢复理论和能量平衡理论对电弧重燃抑制机理进行深度分析。利用ANSYS AUTODYN模拟仿真爆炸气流、气流与电弧间的耦合及灭弧筒内气流压力变化情况,并与试验结果进行比较分析。研究结果表明:仿真中得到电弧熄灭时间约为0.08ms,而试验得到的电弧熄灭时间约为0.4ms,二者灭弧时间均远小于继电保护装置的最快响应时间,其误差在可接受范围内,且熄弧之后未发生重燃现象。这说明了固相爆炸气流灭弧防雷方式提高供电可靠性是可行的。

Study on Arc Extinguishing Characterstics and Mechanism of Suppressing Arc Reburning under the condition of Solid-phase Explosive Vertical Airflow

It is a new kind of lightning protection measure to actively cut off the arc by solid-phase explosive airflow.This kind of measure is to utilize the lightning-induced triggering of the solid-phase explosion airflow to generate high-speed and high-pressure vertical airflow to act on the early fragile period of the germination of the arc,and carries out the extinguishing mechanism of"fast and strong"for the arc.Continued airflow after arc-extinguishing will continue to act on the lightning path to achieve deep suppression of arc-reigniting.The model of the detonation airflow and arc-extinguishing coupling arc was established to obtain the arc-extinguishing criterion.The theory of dielectric recovery and the theory of energy balance is used to analyze the mechanism of arc-reigniting suppression.The ANSYS AUTODYN simulation was used to simulate the detonation airflow,the coupling between the airflow and the arc and the change of the airflow pressure in the arc extinguishing cylinder,and compared with the test results.The results show that the arc extinction time is about 0.08 ms in the simulation,and the arc extinction time is about 0.4 ms in the experiment.Both above-mentioned arc extinguishing times are much shorter than the fastest response time of the relay protection device,besides,the errors are in the acceptable range,and no re-ignition occurs after the arc is extinguished.This shows that it is feasible to improve the power supply reliability of the solid-phase explosion airflow arc-extinguishing lightning protection method.