Simulation analysis of intermittent arc grounding fault applying with improved cybernetic arc model

Abstract

Intermittent arc grounding fault frequently occurs in non-solidly earthed networks. Establishing an accurate arc model is the basis for analysis of fault characteristics. First of all, an improved cybernetic arc model is introduced in this study, which can effectively demonstrate arcing process through controlling the arc length, and which is applied to simulation analysis of intermittent arc grounding fault. Then, a novel method is proposed to identify when the arc would extinguish or restrike. Arc extinction is determined by comparing the stable ignition voltage and air withstand voltage, while arc reignition is dependent on the competition between recovery voltage and air withstand voltage. Finally, a typical simulation model of 10 kV distribution network is built via PSCAD, and impacts of arc model parameters on fault characteristics are analysed. Comparison between simulation results and field data indicates that the arc model can accurately describe arc characteristics and that the intermittent arc grounding overvoltage generated by the suggested method is consistent with the actual case. In the Petersen coil grounded system, arc reignition times turns to be fewer, intermittent arc duration shorter and the overvoltage amplitude lower than those in the isolated neutral system.

Keywords

• overvoltage
• distribution networks
• earthing
• ignition
• arcs (electric)
• power distribution faults
• simulation analysis
• intermittent arc grounding fault
• improved cybernetic arc model
• accurate arc model
• fault characteristics
• arcing process
• arc length
• arc extinction
• typical simulation model
• arc model parameters
• arc characteristics
• intermittent arc grounding overvoltage
• arc reignition times
• fewer arc duration
• intermittent arc duration
• voltage 10.0 kV