Electric Motor Control
10th Edition
ISBN: 9781133702818
Author: Herman
Publisher: CENGAGE L
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Chapter 57, Problem 8SQ
(a)
To determine
Explain whether the resistance of the rheostat is to be increased or decreased to increase the generator voltage.
(b)
To determine
Explain the condition of current change in the generator’s shunt field winding to increase the generator voltage.
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A short-shunt compound wound generator has a shunt field resistance of 77 ohms, a
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armature current is 128 amperes, the generated emf is 234.5 volts. Calculate the
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note: A commutating pole winding is connected in series with the armature winding.
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Chapter 57 Solutions
Electric Motor Control
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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
- a) Explain the main components of AC generator?b) What conditions are necessary for paralleling two synchronous generators?arrow_forwardQ2- Indicate whether the following statements are true or false and correct the false statements 1- The brushes of d.c machine always are placed at the magnetic neutral axis 2- The field current of d.c shunt generator is not affected by load current. 3-The armature voltage of d.c series generator is not affected by load current. 4- A lap winding is most suitable for higher voltage rating machines 5- In de generator, the critical resistance can be increased by increasing its speed 6-In LAP winding the front pitch equal to (yr Ye- yb). 7- The speed of d.c series motor is decreased if the armature current is decreased 8- The compensating winding carrying the field current 9- By tapping field method, the speed of d.c series motor can be controlled below rated value 10- To solve the Commutation Problem in small machines, this can be achieved by increasing the brush widtharrow_forwardThe windings of short-shunt compound dc generator have the following resistances: Armature, shunt field, interpole and series field are 0.5 ohm, 253 ohms, 0.2 ohm and 0.15 ohm respectively When the generator delivers 40 amperes at 500 Volts, its total drop is 2 Volts. What is the generated power?arrow_forward
- 7-The armature voltage of d.c series generator is not affected by load current. 8- In series d-c generator the field winding will be constructed from high number of turns and high cross- sectional area of wire. 9- If field resistance of a d.c. shunt generator is increased beyond its critical value, the generator output voltage will exceed its rated voltage 10-The inter pole winding is conected in parallel to field windingarrow_forward3. How can the speed effect on the No Load characteristic And the external characteristic Of the shunt generator?arrow_forwardQuestion 1: What is the voltage (U) read before the generator is excited? If it is zero explain the reason. Question 2: Sketch the no-load using the values U and le recorded. Question 3:Does the generator voltage increase withe the excitation current? Explian Question 4:What would happen if the series properties of the DC compound generato were as much as the shunt properties? Explain.arrow_forward
- 3. Do the excitation current (If) and the generator voltage (Vq) increase with the same ratio ? Explain the reason. 4. What is the required excitation current to obtain the rated voltage at the output terminal of the generator ? What is the percentage of the generator current to its rated value ?arrow_forwardA 10-kw 250-volt compound (long-shunt) generator has a no-load voltage of 230. The shunt field has 800 turns per pole and the seriesfield 8.5 turns per pole. The shunt- and series-field resistances are 80 ohms and 0.07 ohm, respectively. To make the generator flat-compound, it will have a noload voltage of 230 and a full-load voltage of 230; the series field must produce 225 amp-turns. Calculate the total number of ampere-turns provided by each pole at no load and full load.arrow_forwardQ3-(A)- Indicate whether the following statements are true or false and correct the false statements F-The armature voltage of d.c series generator is not affected by load current. In series d-c generator the field winding will be constructed from high number of turns and high cross- sectional area of wire. If field resistance of a d.c. shunt generator is increased beyond its critical value, the generator output voltage will exceed its rated voltage 4-The inter pole winding is connected in parallel to field windingarrow_forward
- Explain the working of Induction Generator with diagramarrow_forward2. This question is regarding the steady state armature current when dead short circuit occurs across the d.c generator terminals. Pick up the correct statement. (A) For a shunt generator the short circuit armature current will be many times larger than the rated current of the armature. (B) For a separately excited generator the short circuit armature current will be many times larger than the rated current of the armature. (C) For a shunt generator the short circuit armature current will be many times lower thanthe rated current of the armature. (D) For a separately excited generator the short circuit armature current will be many times lower than the rated current of the armature.arrow_forwardQuestion 1: What is the voltage (U) read before the generator is excited? If it is zero explain the reason. Question 2: Sketch the no-load using the values U and le recorded. Question 3:Does the generator voltage increase withe the excitation current? Explian Question 4:What would happen if the series properties of the DC compound generato were as much as the shunt properties? Explain. Question 5:Is there any voltage drop when the generator is operating at no-load? Explain the reason. Question 6: State your final observations about the experiment.arrow_forward
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