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

What are operations performed on data in 8085, What are operations performe...

What are operations performed on data in 8085 The various operations performed are Store 8-bit data Perform arithmetic and logical operations Test for conditio

What are frequency response curves, Q. What are frequency response curves? ...

Q. What are frequency response curves? How are they made? Every amplifier has a frequency-response curve associated with it. They provide a "picture" of the performance of an a

Magnetic circuits with air gaps, The creation of a magnetic field in a ring...

The creation of a magnetic field in a ring may need to be accessed by means of an air gap. This is typically used to apply the magnetic field to a current carrying conductor to pro

Selection of right- flex in electricity and gas hazards, Selection of Right...

Selection of Right- Flex : It is also important that the flex we choose is appropriate to the appliance used. Like fuses, the cables and flexes are also rated according to their

Combination of uni-selectors and two motion selectors, Q Using a combinatio...

Q Using a combination of Uni-selectors and two motion selectors, draw a diagram of thousand line exchange and illustrate its working. Ans: The diagram for such an exchange i

Draw a relay construction diagram, Draw a relay construction diagram and br...

Draw a relay construction diagram and briefly explain the operation of a relay. Define the terms normally open and normally closed. Define the terms Set and Reset for relays.

What are the modes used in keyboard modes, What are the modes used in keybo...

What are the modes used in keyboard modes? 1. Scanned Keyboard mode with 2 Key Lockout. 2. Scanned Keyboard particular Error Mode. 3. Scanned Keyboard with N-key Rollover

Estimate conversion time of counter-controlled a/d converter, Q. An 8-bit A...

Q. An 8-bit A/D converter is driven by a 1-MHz clock. Estimate the maximum conversion time if: (a) It is a counter-controlled A/D converter. (b) It is a successive-approximat

Reasons for the augmentation of electromagnetic radiation, Question: Ge...

Question: General EMC Knowledge (a) Give 2 reasons for the augmentation of electromagnetic radiation in urban regions. (b) Pointe aux Diable bears its name due to the a

Pass band of the resulting bandpass filter, A bandpass filter design can be...

A bandpass filter design can be accomplished through the cascade connection shown in Figure, where the frequencies between the two cutoffs fall in the passband of both filters and

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