A 30 star connected 6-pole 60 Hz induction motor draws 16.8A at a power factor of 80% lagging with the following parameters of per phase approximate equivalent circuit referred to the stator. X = 13.25 Q R₁ = 0.24 0 R₂ = 0.14 0 X, = 0.56 Ω Χ, = 0.28 Ω The total friction, windage, and core losses may be assumed to be constant at 450W. For a slip of 2.5% and when the motor is operated at the rated voltage and frequency, calculate i) The speed in rpm ii) The rotor current iii) The copper losses iv) The rotor input hower

A 30 star connected 6-pole 60 Hz induction motor draws 16.8A at a power factor of 80% lagging with the following parameters of per phase approximate equivalent circuit referred to the stator. X = 13.25 Q R₁ = 0.24 0 R₂ = 0.14 0 X, = 0.56 Ω Χ, = 0.28 Ω The total friction, windage, and core losses may be assumed to be constant at 450W. For a slip of 2.5% and when the motor is operated at the rated voltage and frequency, calculate i) The speed in rpm ii) The rotor current iii) The copper losses iv) The rotor input hower

Electric Motor Control

10th Edition

ISBN:9781133702818

Author:Herman

Publisher:Herman

Chapter39: Synchronous Motor Operation

Section: Chapter Questions

Problem 14SQ: Induction motors and welding transformers require magnetizing current, which causes a. lagging power...

See similar textbooks

Similar questions

A 440 V, 22.5-hp, 50 Hz, 3-phase, 4-pole, star-connected induction motor has the following impedances in ohms per phase referred to the stator circuit: R1 = 0.552X, = 1.1050Ra = 0.350X2 = 0.4562 Xy = 27.10 The total rotational losses are 1105 W and are assumed to be constant. The core loss is lumped in with the rotational losses. For a rotor slip of 2.3% at the rated voltage and rated frequency, d) Electrical power,e) Output power,f) Efficiency.
A 440 V, 22.5-hp, 50 Hz, 3-phase, 4-pole, star-connected induction motor has the following impedances in ohms per phase referred to the stator circuit: R1 = 0.552X, = 1.1050Ra = 0.350X2 = 0.4562 Xy = 27.10 The total rotational losses are 1105 W and are assumed to be constant. The core loss is lumped in with the rotational losses. For a rotor slip of 2.3% at the rated voltage and rated frequency, calculate:a) Speed,b) Stator current.c) Power factor,d) Electrical power,e) Output power,f) Efficiency.g The shaft torque of the motor at rated load
A 3-phase, 6 pole, 440 V, 60 Hz, Y-connected induction motor has the following impedances per phase referred to the stator circuit: R1=0.43 Ω, R2=0.54 Ω, X1=1.263 Ω, X2=0.608 Ω, XM=43Ω The total rotational losses are 1100 W and are assumed to be constant. The core loss is lumped in with the rotational losses. For a rotor slip of 2 percent at the rated voltage and rated frequency, Find the motor speed, stator current, output power
The stator resistance of a 1-phase induction motor is 2.5 ohms and its leakage reactance is 2.0 ohms. Onno-load, the motor takes 4 A at 96 V and at 0.25 lagging power factor. The no-load friction andwindage loss is negligible. Under the blocked-rotor condition, the input power is 130 W at 6 A and42 V. Obtain the equivalent circuit parameters.
A 460V, 25hp, 60Hz, 4 pole, Y-connected induction motor has the following impedances in ohms per phase referred to the stator circuit: R1 = 0.641 Ω R2 = 0.332 Ω X1 = 1.106 Ω X2 = 0.436 Ω Xm = 26.3 Ω The total rotational losses are 1100W and are assumed to be constant. The core loss is lumped in with the rotational losses. For a rotor slip of 3.5% at the rated voltage and rated frequency, find the motor’s Speed Stator current Power factor Pconv and Pout Ʈǐnd and Ʈload Efficiency
A three-phase Y-connected 230-V (line-to-line) 7.5-kW 60-Hz six-pole induction motor has the following parameter values in Ω/phase referred to the stator: R1 = 0.294, R2 = 0.144 X1 = 0.503, X2 = 0.209, Xm = 13.25 The total friction, windage, and core losses may be assumed to be constant at 403 W, independent of load. For a slip of 4 percent, determine: (a) stator current, power factor, (b) output torque and power,(c) efficiency when the motor is operated at rated voltage and frequency, (d) the load component 12 of the stator current, the induced torque Tind, and the converted power Pconv for a slip s= 0.04,(e) the maximum torque and the corresponding speed; and (f) the starting torque Tst and the corresponding stator load current 12 start
A 480V, 60Hz, six-pole, Y connected cage rotor induction motor has the followingparameters in ohms per phase referred to the stator: R1=0.5Ω X1=1.1Ω R2=0.45ΩX2=0.6Ω Xm=30Ω The total rotational losses (friction, windage, and core losses) are 1100W and are assumedto be constant. For a rotor slip of 2.2% at the rated voltage and rated frequency, calculate:a) Rotor speedb) Stator currentc) Complex, real, and reactive input power and the power factor of the machined) The air-gap power (Pag) and the developed mechanical power (Pconv)e) Developed electromechanical torque, and the output mechanical torquef) Efficiency
The results of no-load test and block rotor tests on a three-phase, wye- connected squirrel cage induction motor are as follows No load line to line voltage: 418V No load input current: 13.3A No load input power: 1,396.5W Locked rotor line to line voltage: 154.85V Locked rotor input power: 6,840W Locked rotor input current: 57A Resistance measured between two terminals: 0.475 ohm Determine: a. resistance of the stator per phase b. resistance representing the iron losses c. magnetizing reactance d. rotor resistance per phase e, total reactance referred to the stator side
The stator resistance of a 1-phase induction motor is 2.5 ohm and its leakage reactance is 2.0 ohm. Onno-load, the motor takes 4 A at 96 V and at 0.25 lagging power factor. The no-load friction andwindage loss is negligible. Under the blocked-rotor condition, the input power is 130 W at 6 A and42 V. obtain the equivalent circuit parameters.
A three-phase, two-pole, 35 hp, 480 V, 60 Hz, Y-connected induction motor has the following constants in ohms per phase referred to the stator: Rl = 0.322Ω R2 = 0.196 Ω X1 = 0.675Ω X2 = 0.510Ω Xm = 12.5Ω The total rotational losses are 1850 W and are assumed to be constant. The core loss is lumped in with the rotational losses. For a rotor slip of 3% at the rated voltage and rated frequency, determine the following: (a) The speed in rpm and in rad/s (b) The stator current (c) The power factor (d) The developed power and output power (e) The developed torque and output torque (f) The efficiency.
A 480V, 60Hz, six-pole, Y connected cage rotor induction motor has the followingparameters in ohms per phase referred to the stator: R1=0.5ΩX1=1.1Ω R2=0.45ΩX2=0.6Ω Xm=30Ω The total rotational losses (friction, windage, and core losses) are 1100W and are assumedto be constant. For a rotor slip of 2.2% at the rated voltage and rated frequency, calculate:d) The air-gap power (Pag) and the developed mechanical power (Pconv)e) Developed electromechanical torque, and the output mechanical torquef) Efficiency
A 1100 V, 50 Hz, delta connected induction motor has a star connected slip ring rotor with a phase transformation ratio of 3,8. The rotor resistance and standstil leakage reactance are 0,012 ohm/phase and 0,25 ohm/phase respectively. Neglecting the stator impendance and magnetising current determine the rotor current at 4 % slip with slip rings shorted. A. 123 A B. 430,5 A C. 560 A D. 742,3 A