Continuous comprehensive line selection technology based on D-S evidence theory

Abstract

Aiming at the single-phase grounding fault in 380 V three-phase AC power system with ungrounded neutral, a fault line selection method considering zero sequence current ratio method, zero sequence current phase ratio method and dual frequency method is proposed in this paper, which makes full use of the fault information such as zero sequence current and insulation resistance to ground of each branch when single-phase grounding fault occurs, The fault degree function and reliability function corresponding to each line selection method are constructed to form a comprehensive line selection strategy. After continuous comprehensive line selection, the multiple comprehensive line selection results are fused by using D-S evidence theory to obtain the final line selection results. The simulation calculation on MATLAB/ Simulink platform shows that this method is feasible and improves the accuracy of line selection to a great extent.

Keywords

• Ungrounded neutral
• Single-phase grounding fault
• Fault degree function
• Reliability function
• D-S evidence theory