What magnitude of frequency change would cause a 10% droop governor to move its generator from zero output to full output in a 60 HZ system?

To understand why the correct answer is 6 Hz for a 10% droop governor in a 60 Hz system, it's important to first grasp the concept of droop control in generators. Droop control is a method used to control the output of generators and to maintain system frequency stability during load changes.

In a system operating at 60 Hz, a 10% droop indicates that for a frequency deviation of 10% (which is derived from the nominal frequency of 60 Hz), the governor will respond to maintain system balance. The 10% droop means that for every 1% change in frequency from the nominal frequency, the generator's output changes correspondingly.

Since 10% of 60 Hz is 6 Hz, this means that a frequency drop from 60 Hz to 54 Hz (a change of 6 Hz) would prompt the generator to go from zero output to full output. The governor is designed to start increasing the output as the frequency drops to meet the demand, effectively utilizing its droop characteristic.

This relationship between frequency change, droop percentage, and generator output is critical for maintaining grid stability and ensuring a reliable power supply, especially during fluctuations in demand or generation.

Understanding this principle clarifies