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!
Equivalent Circuit of a Polyphase Induction Machine
The inductionmachinemay be regarded as a generalized transformer inwhich energy is converted and electric power is transferred between stator and rotor, along with a change of frequency and a flow of mechanical power. At standstill, however, the machine acts as a simple transformer with an air gap and a short-circuited secondary winding. The frequency of the rotor-induced emf is the same as the stator frequency at standstill. At any value of the slip under balanced steady-state operation, the rotor current reacts on the statorwinding at the stator frequency because the rotating magnetic fields caused by the stator and rotor are stationary with respect to each other.
The induction machine may thus be viewed as a transformer with an air gap and variable resistance in the secondary; the stator of the induction machine corresponds to the transformer primary, and the rotor corresponds to the secondary. For analysis of the balanced steady state, it is sufficient to proceed on a per-phase basis with some phasor concepts; so we will now develop an equivalent circuit on a per-phase basis. Only machines with symmetrical polyphase windings excited by balanced polyphase voltages are considered. As in other discussions of polyphase devices, let us think of three-phase machines as wye-connected, so that currents are always line values and voltages are always line-to-neutral values (on a per-phase basis).
The resultant air-gap flux is produced by the combined mmfs of the stator and rotor currents. For the sake of conceptual and analytical convenience, the total flux is divided into a mutual flux (linking both the stator and the rotor) and leakage fluxes, represented by appropriate reactances.
i have assignment about wien bridge oscillator i need help to how to degsin the circuit using ltpsic
Q. Athree-phase, 600-kVA, 2300:230-V,Y-Ytrans- former bank has an iron loss of 4400 W and a full- load copper loss of 7600 W. Find the efficiency of the transformer for 70% full lo
What are the basic operations of a computer? The basic operations are READ and WRITE.
ppt needed
Define Salient-pole Rotor Construction - Synchronous Machines? Salient-pole rotor construction on the other hand, may be used for low to medium speed applications. The machines
1- Use 4-to-16 decoder and some residue gates to recognize the following functions F1(A,B,C)= S(1,2,4,5,7) F2(A,B,C,D)= S(1,2,4,5,7,10,12,14,15) F3(A,B,C,D,E)= S(1,2,4,5,7,10,12,1
Q. What are the performance measures of oscillator circuits? 1. Stability: This is determined by the passive components. R, C and L determine frequency of oscillations. If R ch
Question 1: a) Describe how pipelining can improves the efficiency of the fetch-execute cycle. b) Explain the term superscalar architecture. c) Explain the term prin
Q. Find the frequency of oscillation, amplifier gain ? The transfer function is found to be where the equation is written as a Laplace transform (s=jw). Analysis of thi
write the working and construction of dc motor.
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