Question: 2consider a separately excited dc motor having the following nominal...
2)Consider a separately excited DC motor having the following
Pn = 75KW , Nn= 2200rpm, Ia=260A and R=0.058(ohm). The motor drives a mechanical load
at its nominal torque value. The load torque-speed characteristic is Tl= 30+kw^2
a)The motor speed is controlled by changing the supply voltage. Determine the required
input voltage value to change the motor speed as n=1100rpm
b)The motor soeed şs controlled by inserting an external resistance to the armature
winding. Determine the required resistance value to change the motor speed as n=1100rpm
c)Calculate the power requirements for a)and b)What is the reason of the power difference
between two cases?
d)What is the motor no-load speed when the motor is supplied from 100v different graph
e)Draw the torque-speed characteristic of the motor on load into the same graph