基于辐射电磁波监测技术的断路器开断性能研究

断路器在开断电流时,当触头两端的电压高于触头间灭弧介质的击穿电压时,动静触头将发生击穿,产生开关电弧,并激发空间高频的电磁波向外辐射。向空间辐射的高频电磁波信号与灭弧气体特性、机械特性及绝缘结构等多种因素相关,反映着断路器的开断能力。本文仿真计算了断路器辐射电磁波的过程,建立试验研究平台,测量对比了全新触头和退役触头开断过程中辐射电磁波的波形,开展了基于辐射电磁波监测技术的高压断路器开断性能研究。研究结果表明:随着触头表面烧蚀程度的增加,断路器开断性能下降,更容易发生电弧重燃,燃弧时间相对于全新触头会有明显的增加,同时对外辐射电磁波的持续也增多,辐射电磁波的持续时间可以作为判定断路器开断性能的判据。本文的研究内容为辐射电磁波监测技术在断路器开断性能的评估提供了技术参考与依据。

Study on Breaking Performance of Circuit Breaker Based on the Technology of Radiation Electromagnetic Wave Monitoring

In the process of circuit-breakers breaking the current,there will be breakdown between moving and fixed contacts when the voltage between the contacts of interrupter is higher than the breakdown voltage of the arc extinguishing medium,which will generate switch arc and excite high-frequency electromagnetic wave in space to radiate outward. The high frequency electromagnetic wave signal radiated to space is related to many factors such as arc extinguishing gas characteristics,mechanical characteristics and insulation structure,which reflects the breaking capacity of the circuit breaker. This article simulates and calculates the process of circuit breakers radiating electromagnetic waves,establishes an experimental research platform,measures and compares the waveforms of radiated electromagnetic waves during the opening and closing of new contacts and decommissioned contacts,and conducts research on the breaking performance of high voltage circuit breakers based on radiated electromagnetic wave monitoring technology. The research results show that with the increase of the degree of ablation on the surface of the contact,the breaking performance of the circuit breaker decreases,and the arc re-ignition is more likely to occur. The arcing time will increase significantly compared to the new contact,and the duration of the externally radiated electromagnetic waves will also increase. The duration of the radiated electromagnetic wave can be used as a criterion for judging the breaking performance of the circuit breaker. The research content of this paper provides technical reference and basis for the evaluation of the radiated electromagnetic wave monitoring technology in the circuit breaker opening performance.