Equivalent circuit of a polyphase induction machine, Electrical Engineering

Assignment Help:

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.

328_Equivalent Circuit of a Polyphase Induction Machine.png

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.


Related Discussions:- Equivalent circuit of a polyphase induction machine

Hybrid parameters, Hybrid parameters (or) h - parameters:- If the ...

Hybrid parameters (or) h - parameters:- If the input current that is denoted as i 1 and output Voltage that is denoted as V 2 are takes as independent variables, input v

Triac - power semiconductor devices , Triac  As the  name  suggests T...

Triac  As the  name  suggests TRIAC  is advice which  has three  electrodes and works  on AC.  The three terminals of triac are MTI ( Main Terminal ) MT2 ( Main  terminal ) an

Explain the working of asynchronous (ripple) counters, Explain the Working ...

Explain the Working of Asynchronous (Ripple) Counters? An external clock is connected to the clock input of the first flip-flop (FF0) only. Thus FF0 changes state at the falli

Society in engineering, Cite a specific example in which the engineer must ...

Cite a specific example in which the engineer must provide maximum efficiency for a given cost

Power distribution, Determine the current through each parallel branch of t...

Determine the current through each parallel branch of the system

Energy conservation , Energy conservation: NEP envisages a voluntary a...

Energy conservation: NEP envisages a voluntary approach initially for promoting energy conservation along with emphasis on labelling of appliances. Gradually as awareness incr

Show power and power factor in ac circuits, Q. Show Power and Power Factor ...

Q. Show Power and Power Factor in ac Circuits? Power is the rate of change of energy with respect to time. The unit of power is a watt (W), which is a joule per second (J/s). T

Enhancement operation of p-channel enhancement mosfet, Q. Show the Enhancem...

Q. Show the Enhancement operation of p-channel enhancement mosfet? As the gate terminal is insulated from the channel by the silicon dioxide layer, we can also apply a negative

#DSP ., #The requirement is as follows- There is a signal which is in the r...

#The requirement is as follows- There is a signal which is in the range of 0 to 5Hz. This signal frequency composition is to determined. The resolution of the determination is 1Hz.

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

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!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd