An interesting way to correct the power factor in plants with many large motors is to have some of the motors synchronous types and run them with high DC rotor field current so they are over excited. This gives the motor a leading PF which then compensates for the lagging power factor of the induction motors.

 

The implications of PF depend largely on the systems capacity. The contribution of high AC demand during hot weather has brought systems down, that were already near capacity. Systems that are loaded lower than capacity have little care for poor PF.

You know going forward, that as further demands are placed on aging systems, that PF will play a larger roll.

 

An interesting way to correct the power factor in plants with many large motors is to have some of the motors synchronous types and run them with high DC rotor field current so they are over excited. This gives the motor a leading PF which then compensates for the lagging power factor of the induction motors.

Long known solution, even back in the 70's when I was in school. Some big factories would have huge synch machines running just for that purpose, but they were expensive so not typical that the savings on the electric bill would justify that.

 

ronv... that photo's a fake!!

It's never night over the entire EARTH at the same time! Plus, you'd have to have an awful long arm for a selfie THAT big!

Looks good to me.

It's a stitch of multiple satellite images.

 

I believe it wouldn't hurt to improve PF.
PF doesn't necessarily means for only inductive loads.

Specifically in where I live in, excessive use of cheap CFL with low PF really gives negative impact.

That's why I'm asking earlier about running CFL on DC SMPS with APFC.