Simulation for Self-extinction Behavior of Secondary Arc in Transmission Lines

The self-extinguishing behavior of secondary arcs affects the single-phase re-closure time of transmission lines,so it is important to improve the power system's transmission capacity and reliability.Based on the classic Mayr arc model,the non-linear time-varying arc resistance was introduced to describe the condition of an arc channel,and the arc resistance equations were established.By analyzing the movement characteristics of the secondary arc,the arc's real time length was obtained to iteratively compute the arc resistance.Then an arc resistance criterion was proposed to judge whether arc extinguishes by itself or not according to the law of energy conservation.The equivalent circuit of the arc resistance connected with the system circuit was also put forward to calculate the arc characteristics,and the simulation flow for the self-extinguishing behavior of the secondary arc was further expressed in detail.With the arcing test data at low currents,the parameter estimation was performed for this arc model,and some waveforms of arc voltage,current,resistance and arcing duration were obtained.According to the obtained results,the potential gradient of secondary arc is in a range of 1 500~2 000 V/m.The calculation waveforms are close to the test results,and the arcing duration error is within the permission error of engineering.It is concluded that the presented secondary arc model and its simulation method are reasonable and practicable.