Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
Q. Three-phase source voltages and phase sequence?
The elementary three-phase, two-pole generator shown in Figure has three identical stator coils (aa, bb, and cc) of one or more turns, displaced by 120° in space from each other. The rotor carries a ?eld winding excited by the dc supply through brushes and slip rings. When the rotor is driven at a constant speed, voltages of equal amplitude but different phase angle will be generated in the three phases in accordance with Faraday's law. Each of the three stator coils constitutes one phase of this single generator. If the ?eld structure is so designed that the ?ux is distributed sinusoidally over the poles, the ?ux linking any phase will vary sinusoidally with time, and sinusoidal voltages will be induced in the three phases. These three induced voltage waves will be displaced by 120 electrical degrees in time because the stator phases are displaced by 120° in space. When the rotor is driven counterclockwise, Figure (a) shows the wave forms and Figure (b) depicts the corresponding phasors of the three voltages. The time origin and the reference axis are chosen on the basis of analytical convenience. In a balanced system, all three phase voltages are equal in magnitude but differ from each other in phase by 120°. The sequence of voltages in Figure 4.1.2(b), corresponding to that of Figure (a), is known as the positive sequence (a-b-c). On the other hand, if the rotor is driven clockwise, then Figure (c) shows the corresponding phasor of the three voltages; the sequence of voltages in Figure (c) is known as negative sequence (a-c-b). Notice that in positive sequence ¯Ebb lags ¯Eaa by 120°, and ¯Ecc lags ¯Ebb by 120°; in negative sequence, however, ¯ Ecc lags ¯ Eaa by 120°, and ¯ Ebb lags ¯ Ecc by 120°.
Exit strategy Venture capitalists and other financiers will negotiate an exit strategy at the point of advancing the money. The exit strategy will involve them realising their
i have Passed all three level of CFA program and i want to join you expert team. will you please tell me will this happen
Project Specifications Complete an individual Financial Report and Analysis. You will select a company that you would like to analyze based on the parameters provided by the
1. If Robinson wishes to maximize its total market value, would you recommend that it issue debt or equity to finance the land purchase? Explain. 2. Construct Robinson’s market va
Describe how society's interests can influence financial managers. Sometimes the interests of a business firm's owners aren't the same as the interests of society. For illustr
Workers interest in participation is also influenced by certain personnel or group characteristics. For example several research studies have shown that both very low and very high
Saven Travel Corporation is considering several investment opportunities in order to diversify its operations. Mr. Saven, president, is trying to determine the firm''''s cost of ca
At 31 July 2010 this instrument meets the definition of a derivative: Small or no initial investment. Its value is dependent on an underlying economic item; exchange ra
I need a report on the topic Factors affecting Composition of Working Capital. Can you please assist me?
You need to tick all the boxes below to acknowledge that your Statement of Advice complies will all the requirements. This checklist needs to be appended to the cover sheet of the
Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!
whatsapp: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd