Effect of Leading Power Factor in Transmission / Distribution Lines

Hello Shivakumar KJ,

1. Increases performance
2. Improves regulation
3. Increases efficiency
4. Minimises circulating currents which contribute heat to the network.

There are other advantages, have a look here:

http://cr4.globalspec.com/comment/145219

If you need further help .....

Sparkstation

I'm having a little difficulty supporting your comments about leading PF on distribution circuits. Reactive currents,. either capacitive or reactive represent I² R losses on the feeder. Why do you want them? Sometimes it's a method of cheating to improve voltage levels when in fact the line should be re-conductored. A delta configuration (under some conditions) can increase triplen harmonics. What circulating currents are you referring to? I am now retired after 35 years with the power company and this would be a new philosophy in power engineering. Leading RKVA can create negative sequence currents (Symmetrical Component Calculations) that can promote generator instability in a power grid.

I need to keep up on the latest, Can you provide an IEEE technical reference?

Thanks Snakers

Hello Snakers,

You are quite correct, of course, and your diligence brings reward.

"I need to keep up on the latest, Can you provide an IEEE technical reference?

No. I am presently (Remember it is now Christmas Eve at my Present Location my helpers and myself ) unable to do so.

Sometimes I throw into the Forum an "interesting" part of an answer.

You have located my "interesting part", and had the courage to debunk it.

So, The Awards Committee have much pleasure in giving you this fine

Because it is the Season for People of Goodwill, you also get this useful personalised

There is also the Bonus of a "Good Answer" added to your Profile, along with a picture taken a few years ago, of me sitting on a stool, with a small child on my knee.

Happy Christmas - Kind Regards.....

Merry Christmas

ideal situation is when PF value is unity.However pf around 0.95 is considered best and good. A leading PF beyond unity has similar effect as a low power factor apart from costs.

Hi,

Distribution system load is an inductive load. A leading power factor of the load (for example due to a large capacitor bank connection with small load) results that the voltage magnitude at load side will be larger than that at the source side. Hence the reactive power will flow from the load towards the source. Injecting a reactive power to the source bus will affect the voltage magnitude of all the customers connected to that source.

Regards

This is directed to M/s Shivkumar and Snakers,

The effects on generator, transmission and load, each are different. The equivalent circuit of the generator has an ideal ac source in series with the synchronous impedence, which is primarily inductive. This results in a drop due to the load current. The drop (reduction) is more with inductive loads, less with resistive load (quadrature relation) and negative with capacitive or leading p.f. loads. If the drop is negative it boosts the voltage.

The transformers, transmission line etc., which come in the circuit all have inductive impedances and add to the generator's impedance. The effect of load current even if of unity pf, results in a voltage reduction at the load end. This can be corrected by boosting the load voltage with either tap changing transformers or capacitive networks. The effective line current due to capacitive component, if overcompensating the inductive component of the load, is higher than before and so contributes to additional losses all the way. Finally it is a trade off and needs judicial selection and handling.

Capacitors also cause increased harmonic currents and switching surges if directly connected on to the power line without compensating filters. It can also cause overvoltage to loads nearer to the generator.

DT