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!
When a machine has more than two poles, only a single pair of poles needs to be considered because the electric, magnetic, and mechanical conditions associated with every other pole pair are repetitions of those for the pole pair under consideration. The angle subtended by one pair of poles in a P-pole machine (or one cycle of flux distribution) is defined to be 360 electrical degrees,or2π electrical radians. So the relationship between the mechanical angle m and the angle in electrical units is given by
because one complete revolution has P/2 complete wavelengths (or cycles). In view of this relationship, for a two-polemachine, electrical degrees (or radians)will be the same asmechanical degrees (or radians).
In this section we set out to show that a rotating field of constant amplitude and sinusoidal space distribution of mmf around a periphery of the stator is produced by a three-phase winding located on the stator and excited by balanced three-phase currents when the respective phase windings are wound 2π/3 electrical radians (or 120 electrical degrees) apart in space. Let us consider the two-pole, three-phase winding arrangement on the stator shown in Figure.
The windings of the individual phases are displaced by 120 electrical degrees from each other in space around the air-gap periphery. The reference directions are given for positive phase currents. The concentrated full-pitch coils, shown here for simplicity and convenience, do in fact represent the actual distributed windings producing sinusoidal mmf waves centered on the magnetic axes of the respective phases. Thus, these three sinusoidal mmf waves are displaced by 120 electrical degrees from each other in space. Let a balanced three-phase excitation be applied with phase sequence a-b-c, ia = I cos ωs t ; ib = I cos(ωs t - 120°); ic = I cos(ωs t - 240°) where I is the maximum value of the current, and the time t = 0 is chosen arbitrarily when the a-phase current is a positive maximum. Each phase current is an ac wave varying in magnitude sinusoidally with time. Hence, the corresponding component mmf waves vary sinusoidally with time. The sum of these components yields the resultant mmf.
principle and operation of a 3phace induction motor
Q. For the 4-bit D/A converter of Figure with V ref =-5 V, determine the range of analog output voltage and the smallest increment. Ans. The binary input range is from 0
Ask question #Minimum 10] In the system shown in Figure 4-1, the rated voltage of the line is 110kv, and the conductors are all LGJ-120 type. The parameters are: r1=0.21O/km,x1=0
Interpreter- High level language The interpreter is a program which translates the high level program into objects program statement wise . it reads one statement of
why we plot graph to find bandwidth is drawn b/w av/avmax v/s frequency not av v/s frequency?
Q. Show that the image frequency for an FM station does not fall in the range of 88.1-107.9 MHz, regardless of the choice of high- or low-side local oscillator.
Demodulators for FM Figure shows a block diagram of a general FM demodulator, which is implemented by generating an AM signal whose amplitude is proportional to the instantane
Q. Show the Decimal to Hex Conversion? To convert the decimal to the hex is slightly more difficult. The usual method to convert from decimal to hex is repeated division by 16.
A balanced star-connected load is connected across a three phase 450V 50 Hz AC supply. Each load element has an impedance of 5+j12 Ω. Calculate: (i) The power factor of the
The Parallel Resistance rule Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4
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