PFI Panel

I suggest using the PFI at the bus where most of your inductive loads are connected instead of adding it to the generator panel. This will decrease the system current from the PFI point to the generator and hence will

- (1) decrease the voltage drop at load point

- (2) decrease the loss in cable conductors

- (3) decrease the transformer loss (if any)

- (4) improve the system stability and overall system performance

- (5) improve the efficiency and capacity of the generator (from 761 KW to 932 KW)

If you use the PFI at Generator panel, then you will get only the last (#5) benefit.

-MS

Before adjusting the power factor, check the manufacturer's recommendations. Most generator sets with which I am familiar specify rated load at a power factor of .8, and suggest derating the generator load if the power factor is higher.

My dear friend for your information diesel engines for Electrical power generation application are disgned as per ISO standards which clearly specifie engine disgned to develop X kva at power factor 0.8 (example 500Kva at 0.8PF ie 400KW) if you maintain the PF as 0.9 then the load on the engine will be 0.9X500= 450 KW hence you would over load the engine and reduce the life of the engine

crm

What You said is correct Mr.Murali. But We can maintain P.F at o.8 PF. There is no overload problem on DG set.Other wise we have to follow manufacturers reccomendation to improve further.other wise, windings will damage.

If he improves the load power factor by adding capacitors, the total KVA applied to the generator will decrease (unless he changes the load). The KW should stay constant. There isn't any problem in doing this.

You will not obtain a short payback though. You can expect that about 1% of the KVARS are loss KW. You are not likely to ever pay for the cost of the capacitor banks if all you want is to improve is the PF. A hundred KVARs banks will save about 1KW. This is 8760KWh per year if running continually. At $0.10 per KWh it is $876 per year. Your bank, its controller and enclosure will cost between $5000 and $10000 once installed. The payback will be between 6 to 8 years. It all depends on your fuel cost.

The fuel consumption is mostly function of the KW. The KVARs add very little (~1%) to the fuel consumption unless they are so high that the generator does not operate properly.

Uhhh... extra VAs like VARs do not affect engine load. Only real power watts will cause load on the engine. VARs are just recirculating magnetism from the inductive loads back to the generator and raise the amps and as such raise heat in the windings. Other than a slight benefit of wave form, the PFI will help increase life of the generator (alternator) by lowering the temperature of the windings, but I don't think life of the generator will significantly increase compared to the cost of the PFI and maintenance of the PFI. I believe when you say 'improve from 0.8 tp 0.98' you are reading from the nameplate since I rarely see 0.8 perfect PF on a normal building load. It's almost always 0.88~0.9. So be sure of your measured PF first, which is load dependant. I'd hate for you to read a nameplate of 0.8 PF, have a load of 0.95 actual measured PF, then buy a PFI panel which may adjust the PF to 0.98, only a 0.03 improvement. I work with drilling rigs that have 0.2 PF load during certain cycles and 0.95 at other cycles. Fun stuff.

Also, note your generator temperature rise rating. If the rise is 80*C over 50*C ambient, forget the PFI panel. You have plenty of copper. If the rise is 130*C over 50*C ambient, you don't have much copper and the insulation will start breaking down if you pull full load amps 24/7. I'll guess you have 110*C over 50*C windings.

So, like others point out, if you think you can install a PFI to mathematically pull more amps from your unit, and as such keep raising the load, you will be increasing watts and hence power demand on your engine. This is a small unit and probably the engine was sized spot on to be small, light weight and competitive (no extra kWs). You may need an overhaul at 10,000 hours instead of 18,000 hours.

Good luck

actually the PFI should be connected on the Main Panel after the Transformers so it should not be connected by any mean to a DG Sets, the PFI will work only on the Public Network & it will be offline when you lose the main building power supply.