Explain the synchronous machines, Electrical Engineering

Assignment Help:

Explain the Synchronous Machines?

A synchronous machine, unlike an induction (or asynchronous) machine, only develops torque at a fixed, so called, synchronous speed - ns which is related to the supply frequency f and the number of pole-pairs p as follows:

ns = 60 . f / p

The main application of a synchronous machine is as a generating device for the bulk conversion of mechanical energy (from a gas, steam or water turbine or a diesel engine) to electrical energy. It is therefore found in all types of power generating stations and also standby generating plants. In the case of a steam plant, the machine is often referred to as a turbo-generator, turbine generator or turbo-alternator. Electrical machines are in general reversible in nature meaning that they are capable of operating both as a motor and as a generator. In this sense, the synchronous machine is no exception. A good example of this are pumped-storage hydro-electric schemes such as the one at Dinorwig in North Wales comprising 6 x 315-MW synchronous machines which can be operated as generators or motors. Synchronous motors are more expensive to install than induction motors and are only found in relatively small numbers in industry where there is a requirement both for a constant-speed drive and the ability of reactive power control.

If inverter-fed they can be used in high-speed variable speed drives for traction applications. Small single-phase synchronous motors have been widely used to provide a timing mechanism for processes such as washing machine cycles. A permanent magnet synchronous machine, usually termed as a DC brushless machine, serves as a basis for numerous high performance servo applications for machine tools and industrial robots. The objective of this module is to look at synchronous machines as a central part of a power generation system. In this sense, the following sections will discuss only the fundamental theory of classical synchronous generators and not the machine operating characteristics in motoring mode.


Related Discussions:- Explain the synchronous machines

Give an introductive notes about fet amplifier, Q. Give an introductive not...

Q. Give an introductive notes about FET amplifier ?  The small signal models for the common source FET can be used for analyzing the three basic FET amplifier configurations: (

Calculate the induced armature voltage, Q. A 50-kW, 250-V, short-shunt comp...

Q. A 50-kW, 250-V, short-shunt compound generator has the following data: R a = 0.06 , R S = 0.04 , and R f = 125 . Calculate the induced armature voltage at rated load and t

Signal., explain about signal

explain about signal

Determine the coil resistance, Relays a) Sketch the schematic symbol for...

Relays a) Sketch the schematic symbol for a relay with a single pole changeover switch b) Determine the coil resistance and determine the current at 12Vdc c) Connect the r

Complier -high level language , Complier-High Level language It al...

Complier-High Level language It also  translates the  whole  high  level  program  into object  program if it does not  have any  syntax error. The disadvantage of the  in

Find the power factor and current of the machine, Two identical three-phase...

Two identical three-phase, 33-kV, wye connected, synchronous generators operating in parallel share equally a total load of 12 MW at 0.8 lagging power factor. The synchronous react

Briefly explain the principle and operation of strain gauges, Question: ...

Question: (a) With the help of a clearly labeled diagram explain the functioning of a basic thermocouple. (b) Briefly explain the principle and operation of strain gauges

Determine the percentage reduction in the applied voltage, A large inductio...

A large induction motor is usually started by applying a reduced voltage across themotor; such a voltage may be obtained from an autotrans- former. A motor is to be started on 50%

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