PRR Man posted:
Thank you Jack.
Then the reason why modern high horsepower diesels are now designed with AC traction motors, that are variable frequency?
There are many, MANY reasons for the development & use of AC Traction locomotives, one of the main reasons being the drastic reduction in maintenance costs of the AC 3 phase induction motor (which has only one moving component, i.e. the rotor), over the DC series wound motor, as well was the great increase in torque (tractive effort).