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Example:Calculation of the kVAR rating for 1750kW Motor

Motor Data:
Rating of Motor: 1750kW
System voltage: 6.6kV
Power factor of the motor when running at 75% of full
load : 0.84

(Power factor of the motor is considered at 75% of full
load, assuming that the motor will be loaded at an average
of 75%)

Target Power factor : 0.95 lag ( To improve the power
factor from 0.84 to 0.95, after adding the capacitor bank
in the motor circuit)

Required kVAR of the Capacitor Bank to
achieve the target power factor.

KVAr = KW ((TanQ1- TanQ2)

where
Q1= Cosinsverse(P.F1)Initial Power Factor Angle
Q2= Cosinsverse(P.F2)Target Power Factor Angle

So, required kVAR
=0.75*1750*(tan (cos-1 (0.84)) - tan (cos-1 (0.95)))

= 416kVAR

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