Electrical Machines Q1.10b 1.10 A 7.46 kW, 220 V, 900 r/min shunt motor has a full-load efficiency of 88%, anarmature resistance of 0.08 ohm and shunt filed current of 2 A. Determine thefollowing:If the speed of this motor is reduced to 450 r/min by inserting a resistance in thearmature circuit, the load torque remaining constant, determine the following:(d) The value of the additional resistance inserted in the armature circuit in ohm.

Answered: Image /qna-images/answer/79ded84e-010d-4d50-a601-142475d3c711.jpg

Answered: 1.10 A 7.46 kW, 220 V, 900 r/min shunt…

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 220 V DC series motor runs drawing a current of 30 A from the supply. Armature and field circuit resistances are 0.4 and 0.1 respectively. The load torque varies as the square of the speed. The flux in the motor may be taken as being proportional to the armature current. To reduce the speed of the motor by 50% the resistance in ohms that should be added in series with the armature is
Design a DC motor circuit to drive A fan-type load with a torque equation equal to: TL=1.34×10−7ω2TL=1.34×10−7ω2 N.m The fan speed range is from 500 to 1200 rpm. To achieve the required operation, the armature voltage of the motor is adjusted by a single-phase, full-wave, ac/dc converter. The input voltage and frequency to the converter are 480 V (rms) and 50 Hz. choose the motor type, show the motor rating, αα range, Supply voltage, and frequency, and any required other information Modify the design to automatically adjust the voltage drive the load within the specified speed range. show the control variable, controller type, connection, and controller weights.
Design a DC motor circuit to drive A fan-type load with a torque equation equal to: TL=1.34×10−7ω2TL=1.34×10−7ω2 N.m The fan speed range is from 500 to 1200 rpm. To achieve the required operation, the armature voltage of the motor is adjusted by a single-phase, full-wave, ac/dc converter. The input voltage and frequency to the converter are 480 V (rms) and 50 Hz. choose the motor type, show the motor rating, αα range, Supply voltage, and frequency, and any required other information Modify the design to automatically adjust the voltage drive the load within the specified speed range. show the control variable, controller type, connection, and controller weights. design the single-phase, full-wave, ac/ dc converter. show design specifications, the reason for DC motor selection. correct manual circuit, and correct automatic closed-loop control circuit
A 240-volt series motor has an armature resistance of 0.42 ohm and a series-field resistance of 0.18 ohm. If the speed is 500 rpm when the current is 36 A, what will be the motor speed when the load reduces the line current to 21 A? (Assume a 3-volt brush drop and that of the flux is proportional to the current.). Ans.: 1435 rpm show diagram and step by step process
A series motor runs at 800 rev/min when the voltage is 400V and the current is 25A. The armature resistance is 0.4 ohm and the series field resistance is 0.2 ohm. Determine the resistance to be connected in series to reduce the speed to 600 rev/min with the same current.
Reducing the supply voltage so that Vnew = Vold / V3 reduces the maximum torque of the motor so that Tmaxnew= ...Tmaxold . * .... ...
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2. A 2-pole, 50 Hz induction motor supplies 15 kW to a load at a speed of 2950 rpm. a. What is the motor's slip? b. What is the induced torque in the motor in N-m under these conditions? c. What will be the operating speed of the motor be if its torque is doubled? d. How much power will be supplied by the motor when the torque is doubled?
1. A fundamental DC motor is shown below. VTerminal = 90V. The running current, I = 5A and the rotor resistance, R = 4 ohms. Answer the following: CEMF or E at the running condition = , Power delivered by the source at the running condition = Power converted to mechanical power at the running condition Power lost in heat by the rotor resistance = Show your work for each calculation. Suggest that you clearly mark the schematic. frut
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