Identification of a load–frequency characteristic for allocation of spinning reserves on the British electricity grid

The transmission-grid system operator must maintain the system frequency of a synchronous transmission system within legislated tolerances. This task becomes of particular importance during large power imbalances. To establish a frequency-reserve scheme that maintains a healthy system frequency, the exact behaviour of generators and load response must be known. The paper provides details of load behaviour during a number of large infeed losses. These results show that the current load–frequency sensitivity factor of 2%MW/Hz is justified, and can even be extended to a value of 2.5%MW/Hz. Therefore, this value can be substituted in the calculation of reserve schemes on the electricity grid in Great Britain.