A DC motor having the torquespeed characteristics given in f

A DC motor having the torque-speed characteristics given in figure 1-2 is to be used for applications in which the no load speed varies between 2000 - 3000 rpm. State with explanation the type of DC motor in use. This motor is known to be one of three models with specifications listed in figure 1-3. Explain which motor model is likely the one in use. The motor is used from a starting torque of 0.07 Nm to operate at 2000 rpm. What is the angular acceleration? iv. In another scenario, the motor is meant to operate at 3000 rpm while having a torque load of 0.01 Nm. Explain if the motor is able to perform under this condition.

Solution

From the given data

i) With help of torque speed characterstics motor used is dc shunt motor and it is of type 150612 in

the three mentioned models.In the curve as no load speed reaches to maximum torque becomes zero

ii)150612 is the model which is likely one in use

as per the given problem our application of no load speed varies from 2000 to 3000rpm

so by considering all the three types two of them having no load speed of 2000rpm so which

will not support to reach no load speed of 3000rpm.

iii)To find angular accelaration(alpha)

P=M*alpha

M=rotor inertia(I)*angular speed(w)

now P=I*w*alpha

P/w=I*alpha (T=P/w)

alpha=T/I

from the given data of motor type 150612

alpha=0.07/0.1=0.7rad/s²

^{iv)Yes motor is able to operate with 0.01 torque at 3000rpm because if we see the characterstics given in figure to reach}

^{no load speed of 3000rpm it requires 0.0125 torque approximatley}