QUESTION 9 Dotermi ine the synchronous speed, in revimin, of a 4-pole synchronous motor operating from...
1 a Determine the synchronous speed of a motor that has a frequency of 60Hz and 12 poles. The synchronous speed of a 3-phase, 4-pole induction motor is 60 rev/s. Determine the frequency of the supply to the stator windings. The synchronous speed of a 3-phase induction motor is 25 rev/s and the frequency of the supply to the stator is 50 Hz. Calculate the equivalent number of pairs of poles of the motor. A 6-pole, 3-phase induction motor is...
QUESTION 8 The speed-torque characteristic of an induction motor has been empirically determined as follows: Speed 147 440 41 1.3001.100 Torque 3 Speed 900 750 350 rev/min Torque 13 11 75 N-m 6 9 15 13 The motor will drive a load requiring a starting torque of 7 N-m and increase linearly with speed to 13 N-m at 1,500 rev/min. Find the steady-state operating point of the motor. Enter the one best answer (as a number without the units) from...
Question 1: (3 marks) Calculate the synchronous speed for a 60 kW, 50 Hz, 4 pole cylindrical motor operating at 90% v efficiency.
A 3-phase, 600 kVA, 600 V, 60 Hz, 16 pole, Y-connected, round rotor synchronous motor has Xs = 0.492 22 and a negligible armature resistance. The motor is supplied from a 589V infinity bus, and draws 520 kW of real power at a 0.9 leading power factor. Its mechanical loss at the synchronous speed is 20 kW and the core loss is 15 kW. a) [7 marks] Calculate the generated voltage Ef , the load angel 8, and the efficiency...
(b) (i) Explain briefly why an induction motor can never run at synchronous speed? (2 Marks) (ii) If a six-pole induction motor supplied by a three-phase 50 Hz supply has a rotor frequency of 2.3 Hz, Calculate: (a)The percentage slip (b)The speed of the rotor in rpm (4 Marks) (iii)Draw a typical torque versus slip characteristic curve of an induction motor. If rotor resistance is increased show how the new torque versus slip curve deviates from the original one. (4...
b) A 1MW, 3300 V, 50 Hz, wye-connected, 3-ф, twenty four-pole, synchronous motor has a synchronous reactance of 3.24 2 per phase. Assume armature resistance is negligible. This machine is connected to an infinite bus-bars at 3300 V. Its field excitation is adjusted to provide P.F-1 at rated load Calculate: 0 the internal generated voltage EA and armature current la at rated conditions (S marks) ii) the maximum power and torqu e that the motor can deliver with its Ir...
Question # 2(25 points) A three phase, 200 hp, 2400 V, 60 Hz, 4 pole, Y connected synchronous motor has a reactance of 12 Ω phase and a negligible armature resistance. The motor draws 150 KW at a power angle of-18 Determine a) The synchronous speed of the motor in rpm. (3 points) b) The excitation voltage E. (5 points) c) The line current. (5 points) d) The motor power factor. (3 points) e) The pull-out torque (maximum torque). (3...
Q4. A six-pole, three-phase, 60 Hz induction motor is operating at a speed of 1164 rev min. The input power at this speed is 33 kW and the stator copper loss is 1200 W. Find a) Slip b Airgap power c Rotor copper loss d) Developed torque e) Developed horsepower f) If the rotational losses are 500 W, find the output torque and horsepower
e connected, 60 Hz, 2300 volt, sik pole, cylindrical rotor synchronous motor is 8 leading, neglect losses, the synchronous reactance is 2.5 sand Fp ohm/phase. Determine: (a) Synchronous speed-n, (b) Developed torque in Horsepower Tmec (c) Active Power-P (d) Apparent Power-S (e) Reactive Power-Q (f) Draw the Power Triangle (g) Armature current-1 (h) Excitation voltage-Et (i) Power Angle-8 U) Draw the phasor diagram
e connected, 60 Hz, 2300 volt, sik pole, cylindrical rotor synchronous motor is 8 leading, neglect losses,...
A 1500 kW, unity pf, 3-phase, Y-connected, 2300 V-(line), 30 pole, 60 Hz synchronous motor has a synchronous reactance of 1.95 22/phase. For this problem all losses may be neglected. a. Compute the max. torque in Nm which this motor can deliver if it is supplied with power from an infinite bus, and if its field excitation is constant at the value which would result in unity (1.0) pf at rated load. b. Now, suppose that the motor is supplied...