Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
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.
Select the response describing the steady state effect of increasing the air gap for otherwise identical devices, one operating with constant DC voltage excitation and one with con
Fleming's Right-hand rule states: Let the thumb, first finger and second finger of the right hand be extended such that they are all at right angles to every other. If the first
A synchronous motor with a synchronous reactance of 12 ohms is operating with a current of 100 A at unity power factor supplying power to a large compressor. The phasor diagram for
Factors Affecting High Commercial Losses Commercial losses in our country occur mainly because of the following reasons: Incorrect assessment of the energy consum
Q. Explain braking mode of rotating machines? The braking mode has both mechanical and electric energy input. The total input is dissipated as heat. The machine is driven by th
Q. An antenna with an effective noise temperature of 130 K couples through a waveguide that has a loss of 0.8 dB to a receiver. Find the effective noise temperature presented by th
what is the digital logic circuit for binary divider?
why inductive load is use in electronics circuit?
Transparent latch D flip Flop A typical example of this type of D flop is 7475 shown in figure when CLK connected is enable signal is high and the flip flop is enabled
factors used to classify inductors
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!
whatsapp: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd