Final answer:
Reactive load sharing in a parallel generator set is controlled by adjusting the generator's excitation, as this directly influences the magnetic field and the voltage induced in the stator coils.
Step-by-step explanation:
The correct answer to the question of how to control the reactive load sharing between generators in a parallel generator set is: A. By adjusting the excitation of the generators. The excitation system controls the flow of current in the generator's rotor wiring and thus affects the magnetic field strength. By adjusting the excitation, the voltage induced in the stator coils, and consequently the reactive power generated, can be controlled. This adjustment is key for maintaining power system stability and ensuring that the reactive power (VARs) is properly shared among the parallel generators.
Option B, adjusting the prime mover speed, and option C, adjusting the governor settings, primarily affect the active power (kilowatts) and frequency. Option D, adjusting the power factor correction capacitors, is typically used to correct the power factor of the load and does not directly control reactive load sharing between generators.