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

Speed control of dc motor - motor control , Speed control of DC Motor ...

Speed control of DC Motor The DC  motor  are versatile motors among the  available  electrical  motors due to  their  superior  characteristics. These motors  give a smooth sp

LED, PRINCIPLE OF LED

PRINCIPLE OF LED

Explain ferroelectricity, Explain ferroelectricity. Ferroelectricity: ...

Explain ferroelectricity. Ferroelectricity: - Materials of ferroelectric have a high dielectric constant that is non-linear that is, this depends to a considerable extent on t

Differentiate thermoplastic & thermosetting plastic material, Classify plas...

Classify plastic materials into two categories describe their important properties and give two examples of each. Plastic materials can be categorized in thermoplastic and ther

Evaluate the temperature corresponding to a thermistor, Question: (a) A...

Question: (a) A tube from one end of a differential pressure transducer is placed at the bottom of a cylindrical cup (D= 0.8m, H= 0.1m) to measure mass flow rate. The cup i

Explain digital signal formatting, Q. Explain Digital Signal Formatting? ...

Q. Explain Digital Signal Formatting? After quantization and coding the samples of the message, a suitable waveform has to be chosen to represent the bits. This waveformcan the

Frequency synthesized signal generator, Q. what is frequency synthesized si...

Q. what is frequency synthesized signal generator? Describe its circuit in detail. OR Give the circuit details of frequency synthesizer also explain its working. OR

Designing a switching system, Q. Demonstrate how finite state machine model...

Q. Demonstrate how finite state machine model helps in designing a switching system and give a typical illustration. Ans: Switching systemessentially belongs to class of fi

Determine the bit-error probability for the two systems, Let both coherent ...

Let both coherent ASK and coherent PSK systems transmit the same average energy per bit interval and operate on the same channel such that E b /N 0 = 18. Determine the bit-error p

Which are the different fet amplifiers, Q. Which are the different FET ampl...

Q. Which are the different FET amplifiers? A FET can be used as a small-signal amplifier by connecting one of its lead to signal ground. The other two leads then serve as the i

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