## why power factor is increased as increasing load,...?

## why power factor is increased as increasing load,...?

(OP)

1.why the power factor of induction motor increased as increasing load...?

2.as i know the inductive-reactive is incresed as increasing load(XL= 2*Pi*f*L).

XL = reactive-inductive

pi= 3.14

f= rotor frequecy

L= inductancies

increasing inductive-reactive cause decreasing power factor.

how we can understand this opposite,..? which is the dominant,...?

3. why the current is increased as increasing load,..?

thanks for the respons....

2.as i know the inductive-reactive is incresed as increasing load(XL= 2*Pi*f*L).

XL = reactive-inductive

pi= 3.14

f= rotor frequecy

L= inductancies

increasing inductive-reactive cause decreasing power factor.

how we can understand this opposite,..? which is the dominant,...?

3. why the current is increased as increasing load,..?

thanks for the respons....

## RE: why power factor is increased as increasing load,...?

As a

very rough approximation neglecting leakage reactance, there are two parallel branches:1 - One has the magnetizing reactance Xm which draws a constant inductive magnetizing current, regardless of load.

2 - The other branch has a load resistance R2/s, which draws a load-dependent resistive current which supplies the motor real output power (and rotor losses).

As load increases, the 2nd branch resistive current increases, inductive current stays the same. The sum of these two increases in magnitude and becomes more resistive (higher power factor).

What this simplified approximatte version of the equivalent circuit is telling us is that the inductive current necessary to establish the fields is constant, and the resistive current necessary to supply real output power increases with load.

## RE: why power factor is increased as increasing load,...?

1. Gordon R. Slemon "Magnetoelectric Devices, Transducers, Transformers, and Machines," John Wiley and Sons, 1966,

par 5.4.1 Current, Torque and Speed Relations (for example)

Zr'=Rr'/s + jwsyn x LLr'

PF~(Rr'/s)/[(Rr'/s)**2 + (wsyn x LLr')**2]**(.5)

if you increase the load, the slip s decreases; therefore, PF (Power Factor) increases.

## RE: why power factor is increased as increasing load,...?

I have a page on my web site that may also be of interest, http://www.lmphotonics.com/pwrfact.htm

Best regards.

Mark Empson

http://www.lmphotonics.com

## RE: why power factor is increased as increasing load,...?

## RE: why power factor is increased as increasing load,...?

## RE: why power factor is increased as increasing load,...?

http://www.jmpco.com/tech350.htm

http://www.elec-toolbox.com/Formulas/Motor/mtrform.htm

http://www.fpl.com/savings/energy_advisor/EA-30.html

etc. for more info