what is meant by VFD ?where its useful ?
Answers were Sorted based on User's Feedback
VFD stands for 'variable frequency drive'.
Generally its speed is control by the input frequency,
For example in induction motor, VFD used.
Is This Answer Correct ? | 6 Yes | 0 No |
Answer / sak
given to the answer above, i would like to add few things,
to start and to run the motor at different speeds we require VFD, coz variable speed can be achieved easily by changing the frequency, as change in voltage is complicated.
Is This Answer Correct ? | 6 Yes | 0 No |
Answer / shahulsnfa
In addition to Variable speed operation, VFD can be used as
motor starters which normally makes the load to take only
one time of the rated current at the time of starting. in
large motors you may find VFD as starters also it reduces
the harmonic level in the AC supply to which the load is
connected.
Is This Answer Correct ? | 6 Yes | 0 No |
Answer / p.subash chandrabose
VFD- VARIABLE FREQUENCY DRIVE
VFD can be used as Variable speed operation
VARIABLE SPEED ACHIVED BY AC MOTOR IN 2 STEPS
1. VARY THE FREQUENCY
2. VARY THE POLE
THE FORMULA WAS N=120F/P
Eg:N=120*50 /4
N=1500 RPM
WE CANOT CHANGE THE POLE EASSY
BUT WE CAN CHANGE THE FREQUENCY ACHIVE BY VFD.
Is This Answer Correct ? | 6 Yes | 0 No |
Answer / mehul g. c.
vfd id variable frequency drives by that you can change
input frequency to motor or machine .
it is generally used in motor smooth speed control.
like conveyer, lift, electric overhead cranes, special
operational motors.
in that you can get different speed with changing output
frequency.
Is This Answer Correct ? | 5 Yes | 0 No |
Answer / shivakumar
variable frequency drives, its used for control frequency &
aswell as motor speed.
Is This Answer Correct ? | 4 Yes | 0 No |
Answer / sbb
VFD is defined as "Variable Frequency Drive". The main
purpose of VFD is to control the speed of the drive for
different applications.
The principle behind that VFD as we know that N=(120F)/P:
Where N=Speed
F=Frequency (Indian Freq. 50 Hz.)
P=Poles of motor.(Constant)
So speed is controlled by varying the poles of frequency,but
poles is constant and it will be designed when motor is
manufactured.but we can change the frequency though
PWM,Cyloconverters and by thyristor controlled circuits.
So for AC, speed control through VFD is by V/F controll.By
controlling Voltage or by Frequency or by both we can
control the speed.
Is This Answer Correct ? | 4 Yes | 0 No |
Why restricted earth fault protection is needed? Why can’t differential Protection is sufficient?
Sir, I need a power supply at 380V. The supply I get in three phase is rated 415V. The total supply I have from the supply company is 70KW. Kindly inform if it is better to use a voltage stabiliser for this purpose or a transformer
What types of question are done for diploma students in aptitude test
what is the function of commutator in dc motor?
What is slip in induction motor?
what is the earthing condition between earth & neutral.
what is pf. how to calculate capacitor bank value to maintain unity pf.
18 Answers JH, Saint Gobain, Supreme Treves,
What is floating earthing?
what is bus duct and what is differance between bus duct and bus bar
how to calculate neutrel current
What happens if the capacitive reactance of a transmission line is very high?
what is a drive ?