Prime Mover input versus Generator output

[umoguy]

I was hoping someone could set me straight and maybe point me to some helpful technical papers or documents relating to prime mover input as a function of generator output. What I am really looking to find out is does a unit's prime mover input increase (connected to synchronous generator) as a function of real power (kw) or apparent power (kVA)? I am familiar with varying field current to adjust power factor and I'm curious if load on the prime mover also increases when generating further VARS (keeping KW constant).

 

[Skogsgurra]

Real power (kW) and mechanical power (HP) follow each other. The kvars do not affect the HPs in the first approximation. But there may be some extra losses in the windings of the generator when the power factor is low (high on vars) and that may show up as a slight increase in HPs.

Gunnar Englund

http://www.gke.org

 

[waross]

Kilowatts output of the generator, plus the losses of the generator equals input power to the generator.
Output power of the prime mover (net power) plus the losses of the prime mover equals the gross power of the prime mover.
The losses of the generator are mostly related to the current.
With a poor power factor, the current for the same kilowatt output will be higher, hence the slightly higher losses with poor power factor, as mentioned by skogsgurra.
respectfully