Reversed diode earthing scheme in DC traction power system

Abstract

Reducing rail voltage and stray current corrosion all at once is one of the challenging problems in DC electrified rail transit systems. Stray current is the main reason of corrosion in the metallic parts located in the proximity of the railway. Choosing appropriate earthing scheme is an effective way to decrease corrosion intensity and providing safety for personnel. This paper discusses a possible alternative earthing scheme for Tehran Metro Line 3. A new earthing scheme entitled reversed diode earthed scheme is presented and compared with floating and diode earthed earthing schemes. A comparative simulation of the rail voltage and stray current corrosion level for the proposed scheme is presented. The results stipulate the excellence of the proposed method over the prevalent schemes.