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 minimum dandwidth of the system - fsk and ask, 1. Data is to...

1. Data is to be transmitted using a modem at 9600 bps. Determine the minimum bandwidth of the system with the following modulation methods (a) FSK (b) ASK. Use the excess

Determine line voltage for the y- connected machine, A 3-phase, 16-pole syn...

A 3-phase, 16-pole synchronous machine is driven by a prime mover at a speed of 600-rpm with the stator open circuited. The rotor flux per pole is 0.025-Wb. Determine (a) the fr

Develop a block diagram of an asynchronous decade counter, Q. Counting to m...

Q. Counting to moduli other than 2 n is a frequent requirement, the most common being to count through the binary-coded decimal (BCD) 8421 sequence. All that is required is a four

Stator current control methods - motor control , Stator  Current Control ...

Stator  Current Control Methods The torque  and speed  of an induction motor  can be  controlled  by the  stator  current  the motor  behaviour  is different from that with VS

Block diagram convert into Electrical Circuit, i have block diagram and i n...

i have block diagram and i need to convert it into Electrical circuit and on electrical circuit need to apply state space method.

What is thermal runaway, Q. What is thermal runaway? State one method to pr...

Q. What is thermal runaway? State one method to prevent the same? The effect of changes in leakage current (ICO)  and current gain(b) on the dc bias point is given by the equat

Calculate expected peak demand for transformer, What is the expected peak d...

What is the expected peak demand for a transformer feeding the following loads?                           Connected                 kVA

What is extended memory system, What is XMS? XMS: The memory system is ...

What is XMS? XMS: The memory system is splits in three major parts as: system area, XMS (extended memory system) and TPA (transient program area). The kind of microprocessor in

What are the currents in the high-voltage, Q. A transformer is rated 10 kVA...

Q. A transformer is rated 10 kVA, 220:110 V (rms). Consider it an ideal transformer. (a) Compute the turns ratio and the winding current ratings. (b) If a 2-load resistance

Find the pull that must be exerted by the spring, Q. Figure can also be con...

Q. Figure can also be considered as a simple model of a magnetically operated relay that is commonly used for the automatic control and protection of electric equipment. Consider t

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