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P(f) droop curve

Background​

Modern grids operate at a particular frequency, where the two most common rated frequencies are:

  • 50 [Hz] (e.g. Australia)
  • 60 [Hz] (e.g. USA)

Grid operators must ensure that the grid frequency is maintained very close to the rated frequency. If the frequency deviates too far from the rated frequency, equipment connected to the grid can have serious issues or be damaged. Grid operators achieve this frequency control by implementing a collection of different systems to ensure the total active power being generated in a grid very closely matches the total active power being used in a grid. Common methods to achieve this are:

  • Grid operators dispatch active power commands to generating systems from an operations centre.
  • Generating systems locally adjust their active power output based on locally observed frequency.

This tool is designed to help you understand the latter method. In this method, it is very common for generating systems to have a P(f) droop curve for local frequency control.

Tool​

Project settings
P(f) droop settings
Slope outside deadband: 70.0000 [MW/Hz](base = 175 MW)
P(f) droop calculator
Active power at 51.0000 Hz
24.5000 MW
ΔP -63.000 MW
Generating system active power reduced for over frequency event
Sunny Solar Farm - P(f) droop curve4848.849.650.451.252Frequency [Hz]04070110140180Active power [MW]Pref87.5 MWΔP = -63.0 MW51.0 Hz24.5 MWProject rated active power: 175.0000 [MW]System frequency: 50 [Hz]Pref: 87.5000 [MW]Deadband ±: 0.100 [Hz]Droop: 5.00 [%]Pmin: 0.0000 [MW]Pmax: 175.0000 [MW]Pbase: 175.0000 [MW]Operating point:Frequency: 51.0000 [Hz]Active power: 24.5000 MW
Diagram controls

Revision history​

Version 1 | 10 March 2026​

  • First release