NERC Electric Power Sector Reform (EPSR) Practice Exam

To understand why the expected generation response from a governor droop of 5% corresponds to a +5 MW response when the frequency drops by 0.15 Hz, we need to delve into the concept of governor droop control in power generation systems.

Governor droop is a measure of how much a generator is designed to decrease its output as system frequency decreases. A droop setting of 5% means that for each 1% drop in frequency, the generator is expected to increase its output by a certain amount of megawatts, which is usually expressed in relation to its full capacity.

To calculate the expected response, the following steps can be taken:

1. **Understanding Droop Setting**: A 5% governor droop indicates that if the frequency drops by 5% (which would be a change from 60 Hz to 57 Hz, for example), the generator would be expected to increase its output by its full capacity. The droop percentage is a proportional response to the frequency change.

2. **Calculating Frequency Change**: In this case, we have a frequency drop of 0.15 Hz. Assuming we are dealing with a system where the nominal frequency is 60 Hz, a drop to