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°.
exercise
Step 1) Opportunity Set Graph:Combine 2 of your stocks (Ignore the other 2 stocksfor this step only). Construct an investment opportunity set (the curved set) between the two risk
Ho can we estimate that firm is going to benefit from projec To calculate how firm is going to benefit from project we need to calculate whether firm is earning the required ra
(a) A usual cash flow diagram will incorporate the following. If you are short the CDO and then you receive a fixed amount at the initial point t o . After that you make paymen
What is a marginal cost of capital schedule (MCC)? Is the schedule always a horizontal line? Explain. The marginal cost of capital schedule is a graphic representation of the
Q. Explain about Inventory Turnover Ratio ? Inventory Turnover Ratio: - Definite items of inventory are slow moving. It signifies that their consumption is quite slow and capit
Bill Nicholson wants you to help him prepare the financial case for moving the manufacturing operation to Andover. He has specifically expressed interest in getting answers to th
Why do firms enter an industry when they know that in the long run economic profit will be zero? Firms enter an industry while they suppose to earn economic profit. These shor
A procedure that invented in the 1980s for evaluating the processes of a business to find strengths and weaknesses. Specially, activity-based management finds out areas where a bus
how would you judge the potential profit of Bajaj Electronics on the first year of sales to Booth Plastics and give your views to increase the profit?
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