This is the conclusion of a two-part series on power factor and correction methods that we began last month. We're wrapping up the subject by covering the methods used to increase it. The capacitor causes the current to lead the voltage which tends to offset the lagging current caused by the motor reactance, thereby improving the system power factor. The capacitive current in the capacitors opposes the inductive current in the induction motor. By installing suitably sized and controlled switched banks of capacitors into an induction motor circuit to counter the inductive reactance with capacitance reactance, the power factor is generally improved. To reduce their system losses, electric utilities often encourage all energy users to consume energy efficiently by preparing and issuing their rates and penalties based on certain assumed parameters of power factor.
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