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°.
Repurchase agreement is a contract wherein the seller of a security agrees to buy back the same security from the purchaser at a specified price and time. It is also
Additional Paid in Capital - Amounts paid for stock in excess of its PAR VALUE or STATEDVALUE. Furthermore, other amounts paid by stockholders and charged to EQUITY ACCOUNTS other
Q. Estimation of Working Capital? A firm must estimate in advance as to how much net working capital will be required for the smooth operations of the business. Only then, it c
An asset-backed security is a type of bond or note that is based on a pool of assets, or collateralized by the cash flows from a specified pool of underlying assets. As
The issuer's right to call back the issue before the maturity date is referred to as a "call provision". In case of asset-backed securities, the trustee is grante
Laspeyres Method Laspeyres method uses the quantities consumed during the base period in computing the index number. This method is also the most commonly used method which inc
There are two major factors to be considered while analyzing sovereign bonds. They are: economic risk and political risk. Economic risk is all about the ability a
Leverages 'Leverages' are of prime importance in the analysis of a companies' risk. They give a good picture of the business, financial and the overall risk of a company's oper
strengths and weakness
What is the major difference in the obligation of one with a long position in a futures (or forward) contract in comparison to an options contract? Answer: A futures or forward c
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