Problem 3A 208 V, 45 HP, 50 Hz, 1000 RPM, 0.8-PF leading, A-connected synchronous motor has asynchronous reactance of 4 2 and a negligible armature resistance. The friction, windage,stray, and core losses are all lumped together and approximated to 2.4 KW at rated conditions.3-Phase Synchronous MotorsIf the motor is supplying a 20 HP load at 0.8 leading power factor:1. What is the number of poles of this machine?2. Calculate the output power and the stator copper losses in Watt.3. Calculate the input power supplied to the motor?4. Find the line current and the phase current of the motor?5. What are the internal generated voltage Ea and the load angle d of this motor?Suppose now that the shaft load is increased to 35 HP without any changes in the fieldcircuit of the motor,6. Find the phase current and the line current in this case. What is the new power factor? Problem 4A 3-phase, 381 V, 50-Hz, 50 HP, 4-pole, Y-connected induction motor has its per-phase3-Phase Induction Motorsequivalent circuit when referred to stator side as shown below.The total friction, windage, and core losses can be assumed to be constant at 1000 w,independent of load. The motor is operating at rated voltage and frequency.For a per-unit slip of 0.05, (Use the formula sheet, last page):(a) Find the shaft speed of the motor in RPM and in rad/sec.(b) Calculate the stator input current I1.(c) Find the electrical input power Pin-(d) What are the stator copper losses PSCL-(e) Find the air-gap power PAG-(f) What is the converted power from electrical to mechanical Peony-(g) Calculate the induced torque t¡nd-(h) Deduce the overall efficiency %n.R1=0.42jX1=j2 52jX2=j12+I2R2SjXm= j24 2,0.12S

Problem 3 A 208 V, 45 HP, 50 Hz, 1000 RPM, 0.8-PF leading, A-connected synchronous motor has a synchronous reactance of 4 2 and a negligible armature resistance. The friction, windage, stray, and core losses are all lumped together and approximated to 2.4 KW at rated conditions. 3-Phase Synchronous Motors If the motor is supplying a 20 HP load at 0.8 leading power factor: 1. What is the number of poles of this machine? 2. Calculate the output power and the stator copper losses in Watt. 3. Calculate the input power supplied to the motor?

Problem 3 A 208 V, 45 HP, 50 Hz, 1000 RPM, 0.8-PF leading, A-connected synchronous motor has a synchronous reactance of 4 2 and a negligible armature resistance. The friction, windage, stray, and core losses are all lumped together and approximated to 2.4 KW at rated conditions. 3-Phase Synchronous Motors If the motor is supplying a 20 HP load at 0.8 leading power factor: 1. What is the number of poles of this machine? 2. Calculate the output power and the stator copper losses in Watt. 3. Calculate the input power supplied to the motor?

Introductory Circuit Analysis (13th Edition)

13th Edition

ISBN:9780133923605

Author:Robert L. Boylestad

Publisher:Robert L. Boylestad

Chapter1: Introduction

Section: Chapter Questions

Problem 1P: Visit your local library (at school or home) and describe the extent to which it provides literature...

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A 230-V, 60-Hz, 6-pole, Y-connected, three-phase induction motorhas the following parameters in ohms/phase as referred to thestator: R1 = 12.5, X1 = 21.3, R2 = 28.6, X2 = 13.6, Rc = 4200, andXm = 1800. The friction and windage loss is 3% of the powerdeveloped. If the rotor speed is 1125 rpm, and using the exactequivalent circuit diagram determine the following:(i) the input power,(ii) the stator copper loss,(iii) the rotor copper loss,(iv) the air-gap power,(v) the power developed,(vi) the torque developed,(vii) the efficiency, and(viii) draw the power flow diagram
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