JohnB said:
“Power factor is that of the load & not of the alternator” is right. In an islanded situation (standalone generation system) , the alternator must supply power at a power level and a power factor dependant on the load. The alternator can’t do anything else. Power factor correction in this instance will improve the load power factor (and hence reduce alternator ine current).
If however the alternator is operated in parallel with the grid, power factor of the alternator can be changed by changing alternator excitation (assuming it is a synchronous alternator).
As power factor is ratio of active power to apparant power(KW/KVA) AND active power & reactive component is contolled by alternator feed fuel system and excitation control,hence by controlling these two we can control power factor of load and alternator.