Inertia characteristic

A computer program comprising instructions which, when executed by a computer, causes the computer at least to perform:

• determining first data representing a signal comprising a first variation, the first variation being a variation in the grid frequency over a period of time, the signal resulting from a second variation, the second variation being a variation in provision of electric power to and/or consumption of electric power from the grid, the signal having been filtered according to a first filter defining a first frequency band to at least attenuate frequencies outside of the first frequency band;
• determining second data representative of the second variation on a second frequency band, the second frequency band being substantially the same as the first frequency band;
• and
• determining an inertia characteristic of the electric power grid based on the first data and the second data,
• wherein one of the first frequency band and the second frequency band is set on the basis of the other of the first frequency band and the second frequency band.

A method of determining an inertia characteristic of a synchronous area of an electric power grid, electricity flowing in the grid in accordance with a grid frequency, the method comprising:

• determining first data representing a signal comprising a first variation, the first variation being a variation in the grid frequency over a period of time, the signal resulting from a second variation, the second variation being a variation in provision of electric power to and/or consumption of electric power from the grid, the signal having been filtered according to a first filter defining a first frequency band to at least attenuate frequencies outside of the first frequency band;
• determining second data representative of the second variation on a second frequency band, the second frequency band being substantially the same as the first frequency band;
• and
• determining an inertia characteristic of the electric power grid based on the first data and the second data,
• wherein one of the first frequency band and the second frequency band is set on the basis of the other of the first frequency band and the second frequency band.

A method of determining a local inertia parameter representative of an inertia of a local area of a synchronous area of an electric power grid, electricity flowing in the grid in accordance with a grid frequency, the method comprising:

• determining first data representing a signal comprising a first variation, the first variation being a variation in the grid frequency over a period of time, the signal resulting from a second variation, the second variation being a variation in provision of electric power to and/or consumption of electric power from the grid, the signal having been filtered according to a first filter defining a first frequency band to at least attenuate frequencies outside of the first frequency band;
• determining second data representative of the second variation on a second frequency band, the second frequency band being substantially the same as the first frequency band;
• determining, based on the first data and on the second data, a plurality of first inertia characteristics for each of a respective different variation frequency;
• and
• fitting a function to the plurality of first inertia characteristics, the function being parameterised at least by a local inertia parameter, thereby to derive the local inertia parameter,
• wherein one of the first frequency band and the second frequency band is set on the basis of the other of the first frequency band and the second frequency band.

A method of determining a local inertia value representative of an inertia of a local area of a synchronous area of an electric power grid, electricity flowing in the grid in accordance with a grid frequency, the method comprising:

• determining first data representing a signal in a first area of the electric power grid, the signal comprising a first variation, the first variation being a variation in the grid frequency over a period of time, the signal resulting from a second variation, the second variation being a variation in provision of electric power to and/or consumption of electric power from the grid the signal having been filtered according to a first filter defining a first frequency band to at least attenuate frequencies outside of the first frequency band;
• determining second data relating to the second variation on a second frequency band, the second frequency band being substantially the same as the first frequency band;
• determining, based on the first data, and the second data, a local inertia value relating to the first area using a function parameterised by at least a parameter relating to power flow between the first area and a second area of the electric power grid,
• wherein one of the first frequency band and the second frequency band is set on the basis of the other of the first frequency band and the second frequency band.