-than AC to DC Drives e) higher 6. The efficiency of DC to DC converter to drive de motor is- a) lower b) equal 7- The Four-quadrant operation of de motor can be implanted using- a) Full converter b) Dual converter e) Semiconverter 8. The supply frequency of induction motor using frequency control is changed to - a) above rated frequency. b) below rated frequency. e) Above and below rated frequency. 9. The stable operation in torque- spced characteristic for induction motor occur: c) at slip 05 to Sms 10. The regenerative hraking for de to de converter fed de motor would be effective if the a) between maximum slip and s0 h)at slip 1 operating speed m: a) o b) >u

-than AC to DC Drives e) higher 6. The efficiency of DC to DC converter to drive de motor is- a) lower b) equal 7- The Four-quadrant operation of de motor can be implanted using- a) Full converter b) Dual converter e) Semiconverter 8. The supply frequency of induction motor using frequency control is changed to - a) above rated frequency. b) below rated frequency. e) Above and below rated frequency. 9. The stable operation in torque- spced characteristic for induction motor occur: c) at slip 05 to Sms 10. The regenerative hraking for de to de converter fed de motor would be effective if the a) between maximum slip and s0 h)at slip 1 operating speed m: a) o b) >u

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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Similar questions

A single phase Half wave AC voltage controller has a resistive load of 16 ohms with input supply voltage of 240 V, 50 Hz. The delay angle of the thyristors is, a = 21/5. Determine a) The rms output voltage and current. b) Input power factor and Input current. c) Average output voltage and current.
re ot t 6.10 A DC chopper is used in regenerative braking mode of a dc series motor. The dc supply is 600 V the duty cycle is 70%. The average value of armature current is 100 A. It is continuous and ripple free. What is the value of power feedback to the supply? (a) 3 kW (b) 9 kW (c) 18 kW (d) 35 kW
Problem 4.4: A 200-hp, three-phase, 60-Hz, six-pole, 1150-rpm, 0.90-pf induction motor operates with a VFD connected to 480-V lines. The VFD design has CSI fed from a de link. If the motor needs to runs at half the rated speed, determine (a) the rectifier firing delay angle and (b) the VFD output voltage at the motor terminals.
The parameters of a three-phase, 50 Hz, 6-pole, 400 V star connected induction motor are r1 = 0.3 ohm, x1 = 0.5 ohm, r’2 = 0.15 ohm and x’2 = 0.2 ohm. The voltage and frequency of the induction motor is controlled by a power electronic converter (inverter). Calculate the required inverter output frequency and voltage to drive the induction motor load at 0.2 the rated speed of the motor and calculate the current drawn by the motor for that case. The formula for the maximum slip is given below:
g) What is an advantage if the starting Torque of the induction motor is higher than the nominal load Torque? h) What are the main differences when the equivalent circuits of transformer and asynchronous motor are examined?
A 0,9 kW DC shunt motor is loaded by a constant torque of 12 Nm. The armature resistance of the motor is 5 Ω, and the field constant KØ = 3 Vs/rad. The motor is driven by a half wave thyristor converter. The power source is a 140 V, 50 Hz. The triggering angle of the converter is 450 and the conduction period is 1650 . Calculate the motor speed and the developed power.
7. The total rotational losses of an induction motor are a combination of ------- A) Friction losses B) Windage losses. D) Stray losses. C) Core losses. 8. The developed mechanical power can be calculated using the equation of- A) PAG - PRCL. B) PAG w sync C) (1-s) PAG. D) 3 E2Gc. 9. For an induction motor, if the synchronous speed is 1800 r/m, and the rotor speed 180rad/sec, then the slip will be: A) 5.5% C) 6% B) 4.5% D) 4% 10. The power losses in the stator part of the induction motor are B) Core losses D) Friction and windage losses A) Stator copper losses C) Air-gap losses
6. The relation between the field current and the armature current in an alternator with the armature short-circuited can be shown byA. a rated-current 80% pf saturation curve.B. a synchronous impedance curve.C. an open-circuit saturation curve.D. a zero-power-factor regulation curve.
A de machine is controlled by the step-down de-de converter shown below. The armature inductance La =0.2 mH and the armature resistance can be neglected. The armature current is 5A. The Buck converter is operating at the switching frequency is 30 kHz and the duty ratio is 0.8. L₁ + Answer the following questions: 1) Calculate the input voltage (Va) if the output voltage (ea = 200 V). 2) Find the ripple in the armature current (a). 3) Calculate the maximum and minimum values of the armature current (la). 4) Sketch the armature current (ia (t)) and the supply current (id (t)).
(e) Explain the principle of operation of a three phase induction motor. (f) Sketch the IEEE recommended and approximate equivalent circuit diagram of induction motor. Label all key components. Then, with the aid of power flow diagram, list all the power and equations associated with the induction motor including the losses.
Problem 4.4: A 200-hp, three-phase, 60-Hz, six-pole, 1150-rpm, 0.90-pf induction motor operates with a VFD connected to 480-V lines. The VFD design has CSI fed from a dc link. If the motor needs to runs at half the rated speed, determine (a) the rectifier firing delay angle and (b) the VFD output voltage at the motor terminals.
Q1) A 3-phase, star-connected ,220V,6-poles,induction motor has the following constants: (R1=0.32),(R2=0.15).(X1%3D0.50).(X2=0.22),(Xm=132) the total Friction losses+ core losses are( 1000W), the slip is (0.02) determine : 1-the efficiency, 2- the output torque