Question 2 (20 Marks)\ A three-phase,

11.2kW,1750rpm,460V,60Hz

, four-pole

Y

-connected induction motor had the following parameters:

/bar (R_(s)

)

=

(

0)(,)/(b)ar (R_(i)

)

=

(

0.38\\\\Omega ,x_(1))=1.14\\\\Omega ,x_(i)=1.71\\\\Omega

. and

x_(m)=33.2\\\\Omega

.\ One experimenter had decided to run the motor at a speed lower than the base speed followed with a speed higher than the base speed. The objective of the experiment was to study the effect of both speed requirements to the maximum torque developed by the motor. However, the experiment was later abandoned. You are now required to continue the experiment and needed to do the theoretical preparation first. V com fentrol\ a. Discuss suitable control methods to fulfil both speed requirements.\ V/f cedeol\

(CO3: PO3 - 5 marks)

\ b. Propose suitable examples to show the effect of beth speed requirements to the maximum torque developed by the motor and the slip at which the maximum torque is achieved.\

{(: (C03: PO3 - 10 marks) ):}

\ c. Sketch forque curves for both speed conditions as shown in (b) in a single graph.\ (C03: PO3 - 5 marks)

A three-phase, 11.2kW,1750rpm,460V,60Hz, four-pole Y-connected induction motor had the following parameters: Rs=0,R1=0.38,X1=1.14,Xi=1.71. and Xm=33.2. One experimenter had decided to run the motor at a speed lower than the base speed followed with a speed higher than the base speed. The objective of the experiment was to study the effect of both speed requirements to the maximum torque developed by the motor. However, the experiment was later abandoned. You are now required to continue the experiment and needed to do the theoretical preparation first. Vcont.ol a. Discuss suitable control methods to fulfil both speed requirements. ferotrol V/f cateol (CO3: PO3 - 5 marks) b. Propose suitable examples to show the effect of both speed requirements to the maximum torque developed by the motor and the slip at which the maximum torque is achieved. (CO3:PO3-10marks) c. Sketch torque curves for both speed conditions as shown in (b) in a single graph. (CO3: PO3 - 5 marks)