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

Determine the efficiency when the transformer, A 3-kVA, 220:110-V, 60-Hz, s...

A 3-kVA, 220:110-V, 60-Hz, single-phase transformer yields these test data: • Open-circuit test: 200 V, 1.4 A, 50 W • Short-circuit test: 4.5 V, 13.64 A, 30 W Determine th

Write some disadvantages of loosely coupled systems, Write some disadvantag...

Write some disadvantages of loosely coupled systems More complicated due to the needed additional communication hardware. They are less portable and more expensive because o

What is synchronous data transfer, What is synchronous data transfer? I...

What is synchronous data transfer? It is a data method which is used when the I/O device and the microprocessor match in speed. To transfer a data to or from the device, the us

Briefly explain about transients in circuits, Q. Briefly explain about Tran...

Q. Briefly explain about Transients in circuits? The total response of a system to an excitation that is suddenly applied or changed consists of the sum of the steady-state and

Construct the corresponding transfer function, Consider the following IIR f...

Consider the following IIR filter. The initial input data sequence is given by x n = [10 15 20 15 8 6 9 0 0 0] Construct a table that shows the corresponding signal values at

With the help of the structures explain lcd, Q. With the help of the struct...

Q. With the help of the structures explain LCD. A liquid crystal display (LCD) is a thin, flat display device made up of any number of color or monochrome pixels arrayed in fro

Digital electronics, Design a logic circuit when to provide an output when ...

Design a logic circuit when to provide an output when any two or three of four switches are closed.

Find maximum probable percentage error in the measurement, Q. A current of ...

Q. A current of 65 A is measured with an analog ammeter having a probable error of ± 0.5% of full scale of 100 A. Find the maximum probable percentage error in the measurement.

Analog, why h parameter used in low frequency transistor amplitfier

why h parameter used in low frequency transistor amplitfier

Continuity equation - zero electric field, Continuity Equation: Expla...

Continuity Equation: Explain continuity equation and discus the special case of continuity equation when concentration is independent of time and with zero electric field.

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