power factor control or reactive power control 1

[jimmy2times]

I have a system that is allows for power factor control or reactive power control of a generator? This is in the context of a motor/generator air compressor train which synchronises to the grid after start up and exports power under the right process conditions.

If the shaft input power is say 3MW.

Does pf contol allow AVR operation to control excitation voltage to deliver kVArs only?

Does reactive power control allow export of kW and kVArs?

Any help or advice on further reading would be appreciated, Thanks

 

[TheBlacksmith]

Reactive control concerns only KVARS and power factor is the ratio of KW to KVARS. You need KW, that converts into horsepower, heat, light, etc. KVARS are magnetising currents, line losses etc. that are inherent to power system. It sounds like you have a wound rotor synchronous motor on the air compressor where the excitation of the rotor can be varied to supply some of the reactive power to the system, improving power factor and allowing the AVR/genertaor excitation concentrate on maintaining voltage against resistive losses. I say some of the reactive power, because most systems are designed for a slight (.9-.95) lagging power factor; excess KVAR production puts you into a leading power factor and most AVRs don't like that.

 

[JensenDrive]

Basler Electric has a lot of good papers on excitation system setup and theory. You might browse to

http://www.basler.com/html/dwntech.htm

You might start by looking at the paper:
Voltage Versus Var/Power Factor Regulation on Synchronous Generators

 

[edison123]

jensendrive

A lps for you.

*Why a man thinks he outrun a chasing dog when it has twice as many legs?*

 

[jimmy2times]

Jensendrive thanks for the resource link. I'll do some swatting.

Just to get an understanding in the meantime. Are these two statements correct.

All the shaft power of the train gets converted to supplying active power in the form of reactive kVAr (plus machine kW losses).

It would not deliver real power back into the system as the frequency is locked with the grid.

 

[davidbeach]

Shaft power into a generator becomes real power (kW) out of the generator. The excitation system determines the reactive power (kVAr) in or out.