Three phase power supply is used in electric locomotive because of various advantages over other locomotive systems.
Some of the advantages of three phase locomotive over DC locomotive are as follows :
- Three phase locomotive uses three phase traction motors which are robust and requires little maintenance.
- These motors are less sensitive to dust, vibration and heat.
- There are no needs of convertors the power can be fed directly to the traction motors.
- This reduces the losses and becomes lighter as compare to DC locomotive.
- The Power-to-weight ratio of induction motor is much higher as compared to DC motor.
- The induction motors used in three phase locomotives having maximum possible are tractive effort than that attained by the DC motor.
- The regenerative braking is more efficient in three phase locomotive as compared to DC locomotive.
- The weight of the entire system weight is reduced due to reduced weight number of contactors, switches etc.