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!
Electromagnetic torque
The torque is given by the force on the armature winding multiplied by its radius. Force on a conductor in magnetic field B is:
F=B.I.L
so, T=B.I.L.R
The torque opposes the mechanical rotation of the rotor and so the mechanical torque turning the generator must do work against the electromagnetic torque in order to generate the voltage (and current) supplied to the electrical load connected to the generator. Therefore energy conversion occurs from mechanical energy to electrical energy.The flux density B webers/m can be expressed in terms of the flux per pole, φ, to give a relation between the electromagnetic torque to be overcome and current produced.
T=Cm.Ø.Ia
Cm =machine constant
The equivalent circuit representation of an electrical generator is:
The generator itself provides the source tosupply the field current I . Residualmagnetism will provide a small generatedcurrent at first that then builds up as thefield current grows, producing moregenerated current, etc. [NB leaving analternator open circuit will cause thevoltage to build up to the point wherediodes used to rectify the output voltagecan be damaged. Never operate an alternator without an electrical load connected. The output voltage is slightly less than the generated voltage due to the volt drop across the armature winding resistance when current flows. The arrangement of connecting the field winding in parallel with the armature is known as a shunt connected machine. The alternative is to connect the field winding in series with the armature, in which case it as known as a series connected machine.
Reversibility principle of electric machinesAn electric machine can be operated as a generator or motor depending on the operation conditions. This is known as the reversibility principle of electric machines. For example, if the generator above is supplied from an electrical source, it will operate as a motor
Consider the characteristics of patterns that appear on the screen of a CRT, when sinusoidal voltages are simultaneously applied to horizontal and vertical plates. These patterns a
What are loosely coupled systems? In loosely coupled systems every CPU may have its own bus control logic. The bus arbitration is handled by an external circuit, common to all
Successive-approximation analog to digital converter This converter, shown in Figure, also contains a D/A converter, but the binary counter is replaced by a successive-approxim
An induction motor takes 350 kW at 0.8 power factor lagging while driving a load. When an overexcited synchronous motor taking 150 kW is connected in parallel with the induction mo
what is the use of DStat
Lead Acid Accumulators : These are the most common storage batteries which can deliver a heavy current when short-circuited. There are also many other hazards with these accumulat
What are the industrial applications of the project bcd to excess 3 code converter?
The maximum clock frequency for 8085 is 3 MHz
fir and iir filter design
Why we provide the short circuit and open circuit test in transformer
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