POWER FACTOR.

Hello Guest,

This question has often been answered before.

In "Search all of CR4" at the right hand side of the screen, enter the words power factor, and a list of Posts and comments will arrive.

From: http://en.wikipedia.org/wiki/Power_factor

<"....The power factor of an AC electric power system is defined as the ratio of the real power to the apparent power, and is a number between 0 and 1 (frequently expressed as a percentage, e.g. 0.5 pf = 50% pf). Real power is the capacity of the circuit for performing work in a particular time. Apparent power is the product of the current and voltage of the circuit. Due to energy stored in the load and returned to the source, or due to a non-linear load that distorts the wave shape of the current drawn from the source, the apparent power can be greater than the real power. Low-power-factor loads increase losses in a power distribution system and result in increased energy costs....">

Read that article, including all the weblinks, and you should, by then, have a good understanding of "Power Factor".

Kind Regards....

True power equals apparent power when the power factor is 1 (100%)

PF= Pt / Pa (True power is watts) (Apparent power is volt-amps)

Maximum power transfer is equal to 1. Like a Ferrari.

James

I was racing to the answer this as soon as I saw it, but I'm too far past the International Date Line.

Really good answers so far.

We have plenty of scientific answers, all perfect and all correct, but allow me to but a practical spin on this that may be at the root of your question. This comment comes from a power generation viewpoint.

For induction loads such as most electric motors, there is recirculating magnetism between the generator and the load showing as additional amps that does no real work (watts) but it does heat up the circuits in the form of more amps flowing to and fro. This magnetism is required to engage the process of induction rotation of the motor, and it must be maintained, so we need it.

So a generator running at 500 kW 1.0 PF is producing less amps than a generator running at 500kW at 0.8 PF, even though both generators are at 500 kW.

How this also effects the driver of the generator (alternator) is the alternator is less efficient at low power factors. So at 500 kW at 1.0 PF the driver requires X power to rotate the generator, but at 500 kW at 0.6 PF the driver will need a bit more power producing capacity as the alternator efficiency falls of by maybe 1 % or so, even though mathematically PF should not effect "Real Power" (watts), it does in this practical since by lowering the alternator's efficiency.

Clear? Good, then explain it to me as when I re-read this is looks like a child wrote it ! (actually true)

Cheers

To put it simply Power Factor is a measurement of a piece of equipment or load - How far the input Voltage and Current Sinewaves are pulled out of phase. The farther the phase differential; the lower the power factor and the more kva the power source has to produce to power the piece of equipment.

Hi there

I think , my friend is not an electrical guy! , then I make the answer so simple without use of calculation.

power factor is a parameter by which the ratio of actual power(or effective power) is shown either in power productin(electrical generator) or power consumptin(electromotor).Then the larger power factor, the more percentage of useful power.

For example if you start an electromotor without nominal load(idle speed) although the power consumption is less than on full load but the actual load (kw) is a litttle percentage of total consumptin, and vice versa, on full load the effective load is a big percentage of total load in spite of being more than idling.

best regards