Power Systems

Question 1

Answer 1

As long as torque does not exceed its breakdown torque, a synchronous motor will always turn at its synchronous speed. Since power is proportional to torque (P = Tw), power will increase.

D

Question 2

Answer 2

A synchronous motor can be used as a synchronous “capacitor” since it draws a leading current. The parallel connection will change the power factor of the line current, but it will not change the rotational speeds. Both motors will operate as though they were independently connected.

D

Question 3

Answer 3

Formulas for transmission lines start on pg. 368

Find the Characteristic Imedance

Calculate the relection coefficient from the standing wave ratio.

Calculate the terminating load impedance from the reflection coefficient.

Question 4

Answer 4

Question 5

Answer 5

Formula pg. 365

Question 6

Answer 6

Question 7

Answer 7

Question 8

Answer 8

Question 9

Answer 9

Find Synchronous Speed

Find difference in synchronous and actual speed (Slip)

Find Angular Velocity

Question 10

Answer 10

Lots of conversions. Pay attention.

Question 11

Answer 11

Question 12

Answer 12

Question 13

Answer 13

Question 14

Answer 14

Question 15

Answer 15

Formula on pg. 368

Question 16

Answer 16

Use synchronous speed n_s for ac motors formula on pg. 365

Question 17

Answer 17

Find the number of poles per phase

Calculate synchronous speed

calculate slip

Question 18

Answer 18

Use formula on pg. 366

Question 19

Answer 19

Question 20

Answer 20