How often does CPS-1 measure the average frequency against the NERC frequency target?

The correct answer reflects that CPS-1, which stands for Control Performance Standard 1, assesses the average frequency relative to the NERC-approved frequency target at one-minute intervals. This measurement is crucial for maintaining grid stability, as it evaluates how well a balancing authority is capable of keeping frequency close to the desired target.

The one-minute measurement period is significant because it allows for timely detection of frequency deviations that could impact system reliability. Quick adjustments are essential in maintaining power system stability, as frequent and minor fluctuations can lead to larger issues if not addressed promptly.

Other intervals, such as five, ten, or fifteen minutes, would not provide the responsiveness needed to ensure continuous alignment with the frequency target, leading to potential reliability concerns. Therefore, the one-minute interval provides a balance between the need for detailed monitoring and the operational capability of the system.