Primary Control

Primary control power is provided decentrally in power plants to stabilize the grid frequency. The average values that occurred within a quarter of an hour in the APG control area are shown on this page. These are target values that are calculated on the basis of grid frequency deviations. They are normally published within minutes after each full hour.

The primary control reserve is automatically activated through the deployment of turbine controllers in power plants – originating from each operating point. The activation is trigged by deviations in frequency from a set value (50 Hz), while the percentage of the primary control reserve activated also increases as the frequency deviation increases.

The maximum activation (which corresponds to the design fault case) takes place in the case of a frequency deviation of 200mHz and above – the primary control reserve on offer is then fully exhausted. The maximum activation must be attained at the latest 30 seconds after the occurrence of the applicable frequency deviation. It must be available for at least 30 minutes.