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Power FactorImprovement

Presented by:Majid Ali

DEPARTMENT OF ELECTRICAL ENGINEERINGSCHOOL OF SCIENCE AND TECHNOLOGY

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What is Power Factor?

KW: is Working Power (also called Actual Power or Active Power orReal Power).It is the power that actually powers the equipment andperforms useful work.

KVAR:is Reactive Power. It is the power that magnetic equipment(transformer, motor and relay) needs to produce the magnetizing flux.

KVA: is Apparent Power. It is the vectorial summation of KVAR andKW.

To understand power factor, well first start with thedefinition of some basic terms:

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Lets look at a simpleanalogy in order to betterunderstand these terms.

Lets say you are at the ballpark andit is a really hot day. You order upa mug of your favorite brew sky.The thirst-quenching portion ofyour beer is represented by KW

Unfortunately, life isnt perfect. Alongwith your ale comes a little bit offoam. (And lets face itthat foam

just doesnt quench your thirst.)This foam is represented by KVAR.

The total contents of your mug, KVA, is this summation of KW (the beer)and KVAR (the foam).

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So, now that we understand some basic terms, we areready to learn about power factor:

Power Factor (P.F):

is the ratio of Working Power to Apparent Power

P.F = KW/KVA

Looking at our beer mug analogy above, power factor would be theratio of beer (KW) to beer plus foam (KVA).

P.F = KW/(KVA+KVAR)

P.F = Beer/(Beer+foam)

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Basic Concepts

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Types of loads

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Resistive Load

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Inductive Load

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Capacitive Load

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What Causes Low PowerFactor?

Main industrial loads can all be considered to be a combinationbetween resistive and inductive loads Current always lagsVoltage by some angle except in total resistive loads

The inductive loads constitute a major portion of the powerconsumed in industrial complexes.

TransformersInduction motorsInduction generators (wind mill generators)High intensity discharge (HID) lighting

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Disadvantage of Low P.F

Power losses increase, you may experiencevoltage drops.

Increase current, as increase overheating

and premature failure of motors and otherinductive equipment.

Increase KVA rating of system.

Increase KVAR of system.

Increase conductor size.

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Power Factor ImprovementMethod.

Capacitors

Synchronous generators (utility andemergency)

Synchronous motors

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Adding a Capacitor:

Capacitor connection

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Capacitor3-phase InductionMotor

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Adding a Capacitor Bank:

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Other method of improvement P.F

Minimizingoperation of idling or lightlyloaded motors.

Avoiding operation of equipment aboveits rated voltage.

Replacing standard motors as theyburn out with energy-efficient motors.

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Advantage of Good P.F

Lower utility fees by: Reducing peak KW billing demand.

Eliminating the power factor penalty.

increased systemcapacityandreducedsystem lossesin your electrical system.

Increasedvoltage level in your electrical

system and cooler, more efficientmotors

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