COMPARISON OF EARTHING TECHNIQUES FOR SINGLE LINE TO GROUND FAULT IN 11 kV DISTRIBUTION SYSTEM USING SIMULINK

Abstract

In this paper, a new smart earthing method was proposed to reduce the current magnitude of single line to ground fault and thus reduce the damage caused by this fault. Traditional methods of earthing system were studied and compared with the proposed new method using simulation in the MATLAB program to show the superiority of the new method and its economic benefit. The power system characteristics depending on the selection of earthing methods such as charging current magnitude, overvoltage, insulation level, mechanical and thermal damage and fault clearing time are discussed. In this smart technique, a bank of earthing resistors is used according to the characteristics of the earthing fault (fault resistance value), which leads to the passage of a low electric current, but it is detectable regardless of the faults characteristics. Fuzzy Logic Controller technique is used to solve control problem.

Keywords

• earthing methods
• single line to ground fault (SLG)
• bank of earthing resistances
• charging current
• fuzzy logic controller (FLC)
• Low resistance grounding (LRG)
• High resistance grounding (HRG)
• Neutral grounding resistance (NGR)