My friend has
faced this
question! I
don't know
clearly. So
please anyone
give me the
correct and
short answer to
this question?
What is variable
frequency drive?
Types, what is
star to delta?
Why this
arrangement
necessary?




Answers were Sorted based on User's Feedback



Answer / vasu

VFD are used to make the motor to run in desired speed. By
variying the input supply frequency we can vary the speed of
the motor. some other types are VVFD - Variable voltage and
frequency drive, Vector drive.

Is This Answer Correct ?    4 Yes 0 No

Answer / rawjaw

We know a relation speed
say,N=120f/p,speed directly
proportional to freq.In some
applications large motors
used to drive a heavy load,we
start such motors from 0 rpm
& provides initial torque(say
160%) in order to achieve
energy efficient.ok..

Is This Answer Correct ?    4 Yes 2 No

Answer / hitesh kareliya

VFD Means Variable Frequency Drive,So that means we
controll the Pump's RPM via VFD in desired frequency.

Is This Answer Correct ?    1 Yes 0 No




Answer / amit shetkar

see firstly vfd is basically used mainly for 2 purpose i.e to
protect electrical motors & for speed control.
& now about that star delta arrangement it used before motor
in that star connection is used to give smooth start to motor
& when motor achieve it's speed so to maintain that speed
delta connection is used

Is This Answer Correct ?    0 Yes 0 No

Answer / vinay singh

When the elements are connected in neither series nor parallel
to reduce network star delta arrangement is used.

Is This Answer Correct ?    0 Yes 1 No

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