Earthing & Bonding System
When it comes to E&BS in electrified railways, the main point is the E&BS compounds with the traction power return circuit (RC) which is normally the tracks. That makes E&BS a bit complicated for traction power system.
Following objectives are essential to be addressed in a robust and responsive E&BS:
- Integration with RC
- Integration with Protection system
- Safety in all equipment, rail vehicles, stations and workshops
- EMC and Stray Current considerations
- Integration with other power systems
Implementing the E&BS for an electrification Project
As a matter of fact, E&BS can be seen as a separate subsystem or part of the traction power supply and OHL. It means E&BS acts like a referencing bed for those of interconnected subsystem. Therefore, implementation of the E&BS should be done in parallel and close with the related traction power supply and OHL. Following flowchart explains more in details how a great E&BS design satisfies all integrated subjects.
E&BS of various traction systems
Differences in principles and details of various traction system impose different design, equipment and implementation for the E&BS. Generally it can be classified into the following systems:
- E&BS for 25kV with return circuit, booster transformers and dedicated earth wire.
- E&BS for 2x25kV with extra feeder wire and dedicated earth wire
- E&BS for permanent earthed DC traction supply
- E&BS for floating earth DC traction supply with AGS
Integrating the accomplishments