Two tests were performed on a 230-V, 60-Hz, 4-pole, Y-connected, three-phase induction motor and the obtained...
5 Marks) A 4-pole, 3 phase, 50 Hz, 230 V induction motor. Each phase of rotor winding b) has one-fourth the number of turns of each stator. The full-load speed is 1,455 rpm. The rotor resistance is 0.3 Ω and rotor standstill reactance is 1.0 Ω per phase. The rotor and stator windings are similar. Stator losses are equal to 50 Watts. Friction and windage losses are equal to 30 W. Calculate ) Blocked rotor voltage per phase. 2 Marks)...
4. A certain four-pole 240-V-rms 50-Hz delta-connected three-phase induction motor operates at slip 5% at full load and has rotational losses (windage + friction) of 100 W. The stator resistance per phase is 0.2 Ohm. The results of no-load and locked-rotor tests on this motor are as follows: No-load test Locked-rotor test Line-to-line input voltage: 240 V 45 V Input active power: 1100 W 1300 W Input line current: 10 A 30 A Using the tests data, determine parameters of...
A 4 phase, 460 V, 60 Hz, 26.8 hp, 4 pole, Y-connected induction motor draws 25 A at a power factor of 0.9 lagging. Core loss is 900 W, stator copper loss is 1100W, friction and winding losses are 300 W, and stray loss is neglected. The machine shaft rotates at 1738 rpm. Calculate the air gap power and output load torque - [Induction Motor - 15 points) A three-phase, 460 V, 60 Hz, 26.8 hp, 4-pole, Y-connected induction motor...
-23 An 8-pole, 230-V, 60-Hz, A-connected, three-phase induction motor has a rotor impedance of 0.025 + 0.112/phase. The stator winding impedance is negligible. Determine (a) the speed at which the motor develops the maximum torque, (b) the maximum torque of the motor, and (c) the start- ing torque as a percentage of maximum torque. What additional resistance must be inserted in the rotor circuit to make the starting torque equal to 75% of the maximum torque?
A 230 V, 50 Hz, three-phase, Y-connected, 6-pole induction motor has the following per-phase parameters R-0.07 Ro 00 0.08 Ω x, x, 0.3 xm 6.33 At a slip of 2%, determine the followings using approximate equivalent circuit of the motor i) The motor speed in rev/min and rad/s. ii) The rotor current. ii) The stator current. iv) The induced torque. v) The efficiency of 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.
1. A 20 hp, 230 V, 60 Hz, four-pole, three-phase induction motor operating at rated load has rotor copper loss of 331 W, and a combined friction, windage, and stray power loss of 249 W. Determine, (a) Mechanical power developed; (b) Air-gap power; (c) Shaft speed; (d) Shaft torque (10 pts.)
The input power to a 480V, 3 phase, 6 pole, 50 Hz induction motor is 75kW with a line current of 75A and runs at a slip of 2.5%. If the stator core loss is 2 kW, windage and friction loss is 1.2 kW, and the stator resistance per phase is 0.16 ohm. Calculate: a. Power supplied to the rotor (Air gap power) b. Rotor copper loss c. Shaft power d. Efficiency of the motor e. Shaft torque f What...
6. [Induction Motor - 15 points] A three-phase, 460 V, 60 Hz, 26.8 hp, 4-pole, Y-connected induction motor draws 25 A at a power factor of 0.9 lagging. The core loss is 900 W, stator copper loss is 1100 W, friction and windage loss is 300 W, and stray loss is neglected. The machine shaft rotates at a speed of 1738 rpm. Calculate the air gap power and output load torque.
A 480 V, 60 Hz, 4-pole-pair, three-phase, delta-connected induction motor has the following parameters: R1=0.42 Ω, R2=0.23 Ω, X1=0.48 Ω, X2=0.29 Ω, Xm=29.71 Ω where: R1 is the stator resistance R2 is the rotor resistance reflected in the stator; X1 is the stator leakage inductance; X2 is the rotor leakage inductance reflected in the stator; Xm is the magnetising inductance; The rotational losses are 2450 W. The motor drives a mechanical load at a speed of...