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
Discuss need of Caches. Caches are other big thing done in the last 2 decades to enhance performance. Keep things locally when they are going to be used soon. By a physics vie
Standby mode:In this mode, one processor is active and other is on standby, both software and hardware wise. Standby processor brought online when active processor fails. A vital r
Assume that an abrupt Si p-n junction with area 10-4 cm2 has NA=10 17 /cm 3 and ND=10 17 /cm 3 is working at room temperature. It is given that μ n = 700 cm 2 /v-s, μ P =250 cm
The basic operation of battery A simple cell comprises two dissimilar conductors (electrodes) in an electrolyte. Such a cell comprises copper and zinc electrodes. An electric
Given the block diagram of a synchronous counter shown in Figure (a), draw the timing diagram for the first input pulses, with Q 1 , Q 2 , and Q 3 initially at 0.
a. Enlist the benefits and drawbacks of in band and out band voice signalling? b. Describe Channel Associated mode, Channel Non-Associated mode and QuasiAssociated mode of commo
Design : Rather than 100 two-motion selectors as in the case of Design 3, let's consider only 24 two-motion selectors. In the case 24 simultaneous calls can be put through the swi
uses of preset inductor
Q. For a p-channel JFET in its active region, specify the polarities of voltages and the directions of conventional currents.
Static V- I Characteristics The static V- I characteristics of power diodes is shown in figure 1.2 when the anode is made positive with respect to cathode the power dio
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