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
Analysis of diode circuits
1. For the following network: a. Find the differential equation assuming that v ( t ) is the input and the charge on the capacitor q ( t ) is the output. Hints: i R1= ( i R2
Quality of Supply and Services - Power Distribution For effectual management and performance improvement it is essential to measure the several defined parameters of the proc
Question 1 State and Explain Kirchhoff's Voltage and Current Law Question 2 State and prove Thevenine's Theorem Question 3 What is a filter? Design a Constant -K band Pa
Consider a three-phase induction motor with a normal torque-speed characteristic. Neglecting the effects of stator resistance and leakage reactance, discuss the approximate effect
why Vout begins to decrease ...
Energy Bands 1) Since isolated atoms are brought together to make a solid, the electron wave functions begin to overlap. 2) Several interactions occur, and, at the proper i
The block diagram for a 3-bit ripple counter is shown in Figure (a). Obtain a state table for the number of pulses N = 0 to 8, and draw a state diagram to explain its operation.
What are Difference Equations? A continuous-time system can be described by differential equations. Likewise, a discrete-time system can be explained by difference equations. T
ADD Instruction This instruction use to add contents of any register or memory location with the contents of accumulator. There are two formats for ADD instruction to ad
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: +1-415-670-9521
Phone: +1-415-670-9521
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd