Automatic Slip Regulator
BACK

dynamic buffer to provide the required running torque to the applications which are experiencing the variable loads (like Crusher, Fibrizor in sugar Industries.) Depending on overloading pattern the speed tends to reduce which increases the slip frequency results to increase in resistance. As load goes down the slip frequency reduces results to reduce the resistance.

In running some applications like Cane Fibrizor, Cane Cutter, Cane Chopper, Crushers , Mixers etc. experiences frequent kick loads / variable load due to uneven raw material feeding. This leads to overloading of the motor due to insufficient motor torque & causes nuisance tripping due to over current, which affects the process & results production loss. To avoid this, 15% fixed conventional buffer resistance is kept in the Motor Rotor circuit to deliver the high torque & to limit current kicks. This is useful when the motor is loading more than 100% for short time. When there is rated load or load less than the actual rating of motor then there is no need of 15% conventional Buffer Resistance in the Motor Rotor circuit. This resistance will create continuous power loss in the form of heat loss.

Slip Regulator / Dynamic Buffer(DB) offers variable Resistance in the Rotor circuit due to slip dependent Resistance technology. When there is kick load / over load, then Slip Regulator offers Resistance instantaneously depending on slip at that load to its maximum value (upto 12 - 15%) & when the load is less than 100% of rated capacity or equal to rated capacity, then Slip Regulator offers 3 to 4% Resistance.

This reduced value of Resistance during under load will help to save the power as compared to conventional Buffer Resistance. In Rotor Resistance Starter / Controller the part of resistance is kept in the Motor Rotor circuit continuously as a Slip Regulator /

Torque Speed Curve

The Slip regulator is designed in such a way that the resistance offered by it is frequency dependent. When the motor starts from zero speed, rotor frequency equals supply frequency & slip regulator resistance is maximum.

RSR = R0 + Ar fr
VR = s × RVss

RRS/Ph = [(RVss / 1.73) / (RA × p.u.Torque)]

With increase in load, motor slip increases & rotor voltage increases. Running resistance is increased to boost motor torque & avoid current kicks.

Range: 37 KW / 415 V to 6,000 KW / 3.3 KV, 6.6 KV & 11 KV.

Salient Features:
  • Slip dependent Resistance provides automatic variation during acceleration & running.
  • Low Starting current.
  • High starting torque.
  • Built in Slip regulator contactor.
  • No moving parts & stepless cutting of resistance.
  • No maintenance.
Applications:

Sugar Industry – Fibrizers, Cutters, Levellers & applications which require high starting & running torque.