Correct Answer - Option 4 : DC train equipment is heavier and less efficient than similar AC equipment.
Railway Electrification System:
A railway electrification system supplies electric power to railway trains and trams without an on-board prime mover or local fuel supply.
Classification:
Here we consider based on the supply given
- Direct current (DC).
- Alternating current (AC).
- Composite system (Both AC and DC).
Advantages of DC Electrification System:
The choice of selecting a DC electrification system encompasses many advantages, such as
- Space and weight considerations and braking of DC electric motors.
- In this type of system, three-phase power received from the power grids is de-escalated to low voltage and converted into DC by the rectifiers and power-electronic converters.
- In the case of heavy trains that require frequent and rapid accelerations, DC traction motors are a better choice as compared to AC motors.
- DC train consumes less energy compared to AC unit for operating same service conditions.
- The equipment in the DC traction system is less costly, lighter, and more efficient than the AC traction system.
- It causes no electrical interference with nearby communication lines.