Adding a Capacitor Bank for 6.6kV/11kV Unit Board at a Power Plant

Why do you bother to maintain the power factor by connecting capacitors? In power plants, UPF can be maintained by proper excitation control of the alternator.

Thanks ElectricalExpert65:

Couple of reasons I am interested in maintaining the power factor on the unit boards:-

1. I can size leaner bus-ducts for the unit auxiliary boards (they are becoming a concern with increasing gen. sizes)

2. Losses in the Unit Aux. Transformer, and the bus ducts are lowest => Better Energy Efficiency

3. Better reactive power support => voltage support during fast bus transfers on unit tripping => more reliable transfers (and fewer outages) and lesser jerk to motors => long term revenue savings, motor health improvement by reduced end winding failures.

Amit.

Power factor is power factor everywhere. These are not only for the generator loading (unnecessary KVA supply by it) but also simply because line losses are there to compensate for due to the excess current I_tot > I_active.

may be the power plant do not impose penalty on themselves so they don't put it.

Or may be there is enough complication already in the OM area, the addition of the component may be additional headache.

Another since this is too near the generator itself, any malfunction (especially leading pf) may trip the gen whereas in the normal case, these get distributed on the grid and compensate for someone else's low pf.

There can not be any technical reason for not compensating it, rather it will be more from protection and operations point of view.

Also fixed capacitor I don't think are the preferred, here too you will need apfc - load are not that constant in quite a few of the motors.

BFP may be but others say PA, FD, Pulverisers etc load will be unit load dependent and they do fluctuate much more widely than the BFP load.

BTW you are likely to have a highly capacitive load too? (ESP ?)

What is the actual pf at the Aux level ? that may answer the question.

in power plant we have to maintain the lag. Bcz we r exporting the power. So if it became sa lead the power was taken as a import. if else it came as lag as 0.5 pf there is a huge loss in transmission side.over loaded in motors in industry. failure of equipments and less in efficiency.

i dont n sir plz help me sir