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
Assinment
Q. For a JKFFwith JK = 11, the output changes on every clock pulse. The change will be coincident with the clock pulse trailing edge and the flip-flop is said to toggle, when T = 1
The Ward-Leonard system, which is used in the control of large dc motors employed in rolling mills, is a highly flexible arrangement for effecting position and speed control of a s
Q. (a) Excess-3 code is a 4-bit binary code for the 10 decimal digits and is found useful in digital computer arithmetic. Each combination is found by adding 3 to the decimal nu
Complete the financial reporting for each period and develop recommendations using the templates provided. Procedure 1. Read the case study. 2. Complete the financial re
What is programmable interrupt controller? The Programmable interrupt controller is used when several I/O devices transfer datausing interrupt and they are connected to the sam
Q. A gyrator is sometimes used in integrated circuits to simulate inductances. Consider the circuit of Figure consisting of a gyrator. (a) Show that the impedance as seen to the
Q. Examine the features of a typical PC motherboard? The purpose of this experiment is to examine the features of a typical PC motherboard, including: CPU and co-process
digital voltmeter working principle
This example is concerned with steady-state sinusoidal analysis by using mesh equations and MATLAB. Let us consider the circuit shown in Figure and find the input impedance at the
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