Primary Frequency Response

PFR. Immediate proportional response to system Frequency Deviations.

Last Updated:  June 22, 2025

Tags:  

# frequency-control    # nerc

See Also:  

Fast Frequency Response    Primary Control    Secondary Control    Tertiary Control    Frequency Regulation    Automatic Generation Control    Frequency Stability

Definition by NERC

Source:

The immediate proportional increase or decrease in real power output provided by generating units/generating facilities and the natural real power dampening response provided by Load in response to system Frequency Deviations. This response is in the direction that stabilizes frequency.

Relevant news:

• 2022 Feb., p1, Based on PJM’s frequency response analysis and oscillation detection using highly granularity PMU data, in addition to NERC Resource Subcommittee analysis, there are no near term concerns with inertia in the EI.
• 2021 Nov., p4, PJM proposed “Reliability Products and Services” that involves Inertial in the Frequency Response.
• 2021 March, p11, Inertial and Primary Frequency Response: Generators that provide these types of frequency response are not explicitly compensated for this service under today’s rules.

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