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!
The Three-phase alternator
In this case, three separate sets of coils are wound on the stator and connected to produce three separate outputs. Because of the physical displacement of the coils around the stator, the outputs will have different phases with respect to each other. Three-phase systems are common even when DC outputs are required (e.g. electric alternators to charge a car battery) because of the torque reaction problem mentioned above. The AC output is rectified with a set of six diodes mounted in a single pack (two diodes are needed to rectify each phase).
A two-pole, three-phase alternator is shown in the diagram below. Stator coils AB belong to phase 1, coils CD to phase 2 and coils EF to phase 3. Each pair of coils are connected in series and their outputs add (e.g. A and B are connected in series to produce phase 1 output). Notice it is two-pole because there are only two poles (i.e. one pole pair) on the rotor. The frequency of each phase output is therefore equal to the rotational speed of the rotor.
Unlike the single-phase alternator, it turns out that the torque required to drive a three-phase alternator is constant, with no pulsating component. This is an important advantage.The figure below shows the arrangement for a multipole three-phase alternator. Again, coils A&B, C&D and E&F are connected in series to three differnet outputs, each with a phase shift of 120° apart (because of the physical arrangement of the coils on the stator).
Q. The following data were obtained on a 25- kVA, 2400:240-V, 60-Hz, single-phase distribution transformer: • Open-circuit test with meters on LV side: 240 V, 3.2 A, 165 W •
Turn-on, turn-off, and storage delay: The Bipolar transistor shows a few delay characteristics while turning on and off. Most of the transistors, and particularly power transi
On state voltage drop It is the maximum instantaneous on state voltage measured under pulse conditions to avoid excessive dissipation at a particular junction tem
singly excited magnetic systems
Find the minimum rate of sampling that must be used to convert the message into digital form: (a) If an audio message has a spectral extent of 3 kHz. (b) If a television sign
Collection and Payment Systems Payments are currently made in person in most of the places. Only some places payments could be made on line or by the ATM (Automated Teller Mac
Q. Briefly explain about Wheatstone Bridge? Null measurements are made with bridge circuits and related configurations. They differ from direct measurements in that the quantit
Explain data addressing modes available in microprocessors? Data addressing modes available in microprocessors are given below: Direct Mode Indirect Mode Register Dire
Tariff Filing Asset-wise details for each business of licensee; Audited accounts and financial statements, including cash flows for the preceding years and monthly bal
Q. What happens when a negative bias is applied to the gate of a FET? The result of applying a negative bias to the gate is to reach the saturation level at a lower level of V
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