Exemption from AFPS for Deviating GRFs on Free Governor Control

Under the Automatic Financial Penalty Scheme (AFPS), Generation Registered Facilities (GRFs) will incur financial penalties when they deviate from their dispatch schedules by more than 10MW.

This paper proposed amendments to an existing exemption to the AFPS, specifically where a GRF operates on free governor control and responds positively to a power system disturbance.

GRFs on free governor control operate autonomously. They utilise governors within a generator to automatically adjust output in response to maintain the power system frequency at normal state. Given that governors are in-built mechanism installed within GRFs, any output deviations from dispatch schedules should be recognised as a consequential outcome of governors responding to real-time system frequency fluctuations.

Previously, in the absence of a power system disturbance, a GRF operating on free governor control in such a situation was classified as a deviating GRF and therefore subject to the AFPS despite responding positively to maintain system stability.

EMC proposed rule modifications to:

• remove the dependency on the occurrence of a power system disturbance event; and
• that a GRF on free governor control which responds positively to frequency changes in the power system and is compliant with capability requirements and standards outlined in the Transmission Code, shall be exempted from the AFPS for deviation from schedules.

The Rules Change Panel (RCP) unanimously supported EMC’s recommendations. The Energy Market Authority (EMA) has approved the market rules to reflect RCP’s decision, and the approved rules took effect on 27 November 2025.