Electric Motor Control
10th Edition
ISBN: 9781133702818
Author: Herman
Publisher: CENGAGE L
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Textbook Question
Chapter 39, Problem 11SQ
Varying the DC voltage to the rotor field changes the
- a. motor speed.
- b. power factor.
- c. phase excitation.
- d. slip.
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Chapter 39 Solutions
Electric Motor Control
Ch. 39 - Prob. 1SQCh. 39 - What is the effect of the starting winding of the...Ch. 39 - What are typical applications of synchronous...Ch. 39 - Prob. 4SQCh. 39 - A loaded synchronous motor cannot operate...Ch. 39 - Why must a discharge resistor be connected in the...Ch. 39 - Depending on their power factor ratings, what is...Ch. 39 - At what power factor do incandescent lights...Ch. 39 - Prob. 9SQCh. 39 - The speed of a synchronous motor is fixed by the...
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Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, electrical-engineering and related others by exploring similar questions and additional content below.Similar questions
- In a DC shunt generator, the induced EMF is 230 V, the armature resistance is 0.1ohm and the armature current is 200 A. Determine the terminal voltage.arrow_forwardThe stator of a three-phase, 60-Hz, %pole synchronous generator has 48 slots. Determine (a) the speed of the rotor, (b) the number of coils in a phase group, (c) the coil pitch, and (d) the slot pitch. Sketch the complete winding arrangement of the stator.arrow_forward(a) With neat diagram explain the rotor of slip ring induction motor (b) Draw the circuit diagram of DC series generator with the related equations and write any two applicationsarrow_forward
- 3.An induction motor has a rotor resistance and reactance at standstill of 0.1 ohm and 3.5 ohm respectively. At standstill the voltage induced to the rotor is 60volts per phase. If the slip is 5%, determine the rotor currentarrow_forwardin Speed Control of Three Phases I.M. byVariation of Rotor Resistance Give a comparison among speed control methods of 3-Φ induction motor.arrow_forward2P=4 poles 230V-60HZ 3-phase round rotor synchronous motor is star connected. The synchronous reactance of the synchronous motor is j5Ω/phase, the voltage induced at the beginning of the phase is 200V, and the power angle is 30. Calculate the power and torque produced by the motor, ignoring the armature winding flux resistance.arrow_forward
- what is the conclusion for the concepts of rotating amature and rotating field in an alternator?arrow_forwardis the following correct? True or false? If the rotor of the asynchronous motor is reversed in the rotating field, the machine starts to work as a generator.arrow_forward2P=4 poles 230V-60Hz three phase round rotor synchronous motor is star connected. The synchronous reactance of the synchronous motor is j5 ohm/phase, the induced voltage at the beginning of the phase is 200V, and the power angle is 30. Calculate the power and torque produced by the motor, ignoring the armature winding resistance.arrow_forward
- A three-phase 60-cycle six-pole 220V wound-rotor induction motor has a stator that is connected in delta and a rotor that is connected star. The stator has half as many turns as the stator. For a rotor speed of 1,110rpm. Determine the following (a) the slip (b) the blocked-rotor voltage per phase EBR (c) the rotor generated voltage per phase ER (d) the rotor voltage between terminals (e) the rotor frequency (f) rotor current IRarrow_forwardExplain in details why does the rotor of the three phase induction motor rotate, then determine the speed of the revolving field relative to i) stator field distribution ii) rotor structure.arrow_forwardP-1).. Which of the following determine the amount of torque produced by a single-phase split-phase motor? a) The strength of the magnetic field of the stator b) The strength of the magnetic field of the rotor c) The phase angle difference between the current in the start winding and the current in the run winding d) all of the above P-2). The phase angle difference between the currents in the start winding and run winding of a single-phase split-phase motor is typically 90 degrees. a) true b) false P-3). A centrifugal switch is used to disconnect the________ winding of a non-hermetically sealed single-phase split-phase motor at approximately 75% of rated speed. a) run b) start c) either "a" or "b" d) neither "a" nor "b" P-4). Where an internal centrifugal switch cannot be used, an external______ relay can be used to perform the same function in a single-phase split-phase motor. a) hot-wire b) current c) solid-state starting d) all of the abovearrow_forward
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