starting torque is increased and current is decreased by
using external resistance in a slip ring induction motor.
How??
Answers were Sorted based on User's Feedback
Answer / srb
It is because as the resistance is added in rotor ckt,no doubt impedance increases due to which current decreases but the effect of improved pf predominanats the inc. impedance & hence torque inc. After some tym when motor has achieved considerable speed effect of inc impedance predominanats over improved pf & hence torque decreases.
Is This Answer Correct ? | 4 Yes | 0 No |
Answer / nilkanth tailor
THEIR R BASICALLY TWO TYPES OF INDUCTION MOTOR
1) SLIP RING I.M.
2) SQUIRREL CAGE I.M.
GENERALLY, IN HIGH STRATING TORQUES MOTOR(DC SERIES
MOTOR) HAS HIGH STARTING CURRENT, AND ITS VERY DIFFICULT TO
CONTROL THAT CURRENT...BUT IN SLIP RING I.M THIER IS HIGH
TORQUES PRODUCE WITH LOWER STARTING CURRENT THAT IS MAIN
ADVATAGE...
THE MAIN DIFF BET. SLIP AND SQUIRREL CAGE I.M. IS THAT
1)The rotor of the slip ring motor has more windings than a
squirrel-cage rotor so that induction voltage is higher and
the current for the same field strength lower.
2)During start-up the a typical rotor has 3 poles connected
to the slip ring. Each pole is wired in series with a
variable power resistor.
3)During start-up the resistors reduce the field strength
in the stator. As a result the inrush current is reduced.
Is This Answer Correct ? | 1 Yes | 0 No |
why we are using DC supply in megger?
What is center gravity load in substation?
what is the function of Droop CT and where it is used?
Difference between ups and invertor
why we have to particulary use ACB for below ratings,even available of MCB,MCCB with that range ?
2 Answers QRG Health City, Siemens,
Can you explain operating principle of Inverse Definite Minimum Time” (IDMT) relay
Kindly Tell me name of the book for electrical estimation and costing ,calculation or web site to download
how to find the resistance and gap volatage of the diode??
For overhead protection we use which transformer?
what is suitable cable for 25 HP motor ? start with VFD ac supply 50 hz
What will happen if we introduce negative feedback to a control system that uses a positive feedback?
Yazaki india pvt ltd interview questions qurey related