Question 1: (3 marks) Calculate the synchronous speed for a 60 kW, 50 Hz, 4 pole cylindrical motor operating at 90% v efficiency.
Question 1: (3 marks) Calculate the synchronous speed for a 60 kW, 50 Hz, 4 pole...
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...
(Question 1): (4pts) A three-phase, 2300-V, 60-Hz, 10-pole, A-connected cylindrical rotor synchronous motor has a synchronous reactance of 4.0 82/phase. The armature resistance may be neglected. It is connected to 2300-V source and drives a system with its excitation set to give a PF of 0.9-leading when the power is 500-kW. (a) Sketch the phasor diagram of this motor. (b) Calculate the armature current. (c) Calculate the excitation voltage and torque angle. (d) If the load torque is increased by...
Problem 3:A 480 V, 50 kW, 60 Hz, 3-φ synchronous motor has a synchronous reactance of Xs = 4.56 Ω and an armature-to-field mutual inductance, Laf = 150 mH. The motor is operating at rated speed and terminal voltage and at an output power of 35kW. Neglecting losses in the motor, calculate the magnitude and phase angle of the line-to-neutral generated voltage Eaf and field current I if the motor is operating at (a) 0.9 power factor lagging (b) unity...
Problem 3:A 480 V, 50 kW, 60 Hz, 3-φ synchronous motor has a synchronous reactance of Xs = 4.56 Ω and an armature-to-field mutual inductance, Laf = 150 mH. The motor is operating at rated speed and terminal voltage and at an output power of 35kW. Neglecting losses in the motor, calculate the magnitude and phase angle of the line-to-neutral generated voltage Eaf and field current I if the motor is operating at (a) 0.9 power factor lagging (b) unity...
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 11: (3 marks) A 6 pole, 60 Hz, star connected three-phase induction motor has a rating of Pm = 55 kW and line voltage = 420 V. The slip of the motor is 2% at 0.9 power factor lagging. If the full load efficiency is 95%, calculate the torque developed in the motor.
Question 3. (25 Marks) Parameters of a three-phase, 400 v, 50 Hz, 4-pole, star-connected induction motor are as follows: bl The sum of friction, windage and stray losses are 0.15 kW. The motor is running at 1440 rpm. (a) Calculate the input line current (b) Calculate the stator copper loss and rotor copper loss. (c) Calculate the output power and efficiency.
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...
Question 2 (10 marks) (a) A large 3-phase, 4000 V, 60 Hz, slip of 0.01, squirrel cage induction motor draws a current of 375 A and a total active power of 2300 kW when operating at full-load. The stator is connected in wye and the resistance per phase is 0.05 12. The total iron losses are 23 kW and the windage and friction losses are 10 kW. Calculate the following: i) The power factor at full-load ii) The active power...
Question 2 (10 marks) (a) A large 3-phase, 4000 V, 60 Hz, slip of 0.01, squirrel cage induction motor draws a current of 375 A and a total active power of 2300 kW when operating at full-load. The stator is connected in wye and the resistance per phase is 0.05 12. The total iron losses are 23 kW and the windage and friction losses are 10 kW. Calculate the following: i) The power factor at full-load ii) The active power...