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

How power amplifiers are classified, a. Describe briefly with suitable diag...

a. Describe briefly with suitable diagrams, how power amplifiers are classified with reference to operating point? b. Get the maximum efficiency of class A direct coupled power

Define and explain numerical aperture, Define and explain Numerical apertur...

Define and explain Numerical aperture? Figure shown below shows an incident ray to the fibre, The light bends at two interfaces, one at the air- core interface and the

Revision of basics, Revision  of Basics Although  it is  assumed in th...

Revision  of Basics Although  it is  assumed in this book  that the  reader has  enough  knowledge of  various number systems ( binary, octal and hexadecimal and their relation

C programming., #queComputers are frequently used in check-writing systems,...

#queComputers are frequently used in check-writing systems, such as payroll and accounts payable applications. Many stories circulate regarding weekly pay- checks being printed (by

Why positive feedback is used in oscillator, Q. Why positive feedback is us...

Q. Why positive feedback is used in oscillator? The main application of positive feedback is in oscillators. An oscillator generates AC output signal without any input AC signa

Obtain the thevenin equivalent at terminals, Consider the circuit of Figure...

Consider the circuit of Figure (a), including a dependent source. Obtain the Thévenin equivalent at terminals a-b.

Types of hazards, The contents of compressed gas cylinders can range from h...

The contents of compressed gas cylinders can range from highly flammable substances, such as hydrogen, propane and ethane (acetylene), to toxic gases, such as chlorine, sulphur dio

calculate the current, Find the Thévenin equivalent for the attache...

Find the Thévenin equivalent for the attached circuit and use this to calculate the current in the load.   Circuit information:- Load consists

Find the torque supplied to the mechanical load, Q. The machine of Problem ...

Q. The machine of Problem can be used as a motor. Let the terminals of the coil be connected to a voltage source of 1 kV rms. If the motor runs at 1800 r/min and draws a current of

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