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

Determine the Service and Backwash Rates, Determine the Service and Backwas...

Determine the Service and Backwash Rates The system on site is a pressure sand filter, with a service curve. The filter is backwashed using the feed pump, at a higher flow rate, s

Mixed mode simulator, Mixed Mode Simulator: The circuit is preproc...

Mixed Mode Simulator: The circuit is preprocessed. The test points and waveform markers are located in input and output of the circuit. GND net is set like reference net.

Explain soft ferrites and their applications, Explain Soft ferrites and the...

Explain Soft ferrites and their applications. Soft ferrites and their applications: Such are non- metallic compounds having ferric oxide and one or two bivalent metal oxides as

Squeeze castings, Squeeze Castings: Squeeze casting, also known as ...

Squeeze Castings: Squeeze casting, also known as liquid metal forging, is a combination of casting and forging process . The molten metal is poured into the bottom half

Components in a microprocessor, What are the basic components in a Micropro...

What are the basic components in a Microprocessor? 1) Address lines to refer to the address of a block 2) Data lines for data transmit 3) IC chips 4 processing data

Bjt, what is compensation of bjt

what is compensation of bjt

A Capacitor-Fed, A Capacitor-Fed, Voltage-Step-Down, Single-Phase, Non-Isol...

A Capacitor-Fed, Voltage-Step-Down, Single-Phase, Non-Isolated Rectifier

Electrical circuits, equivalent circuit for transistor using h parameters

equivalent circuit for transistor using h parameters

Explain emergency repairs to rail fracture, Q. Explain Emergency Repairs to...

Q. Explain Emergency Repairs to rail fracture? Emergency Repairs - The fractured rails shall be joined by using the arrangements clamps, fish plates. If the gap at fracture doe

Mixed bonding, Mixed Bonding Displayed by III-V compounds bonding p...

Mixed Bonding Displayed by III-V compounds bonding partly ionic and partly covalent. Ionic character of bonding becomes much more prominent since the constituent atoms m

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