Method and system for analysing electricity consumption

A method for analysing the consumption of electricity of a site equipped with a plurality of items of electrical equipment of different kinds, comprising at least one sensor for the periodic measurement of the current and/or voltage on at least one of the electrical phases upstream of the network supplying the site, as well as a computer for carrying out processing said method comprising:

• sampling at least the current signal at a frequency at least thirty times greater than the fundamental frequency of an electrical supply voltage;
• applying a Fourier transform to each fundamental period of the current signal at least proceeding with a temporal smoothing of said transformed signal by calculating a temporal mean over a characteristic period of change in behaviour of the equipment in the network wherein said characteristic period of change in behaviour comprising a period that is sufficiently long compared with the carrier period and sufficiently short not to cover several events;
• forming a database of signatures suited to the site being studied during a first implementation step, consisting of:
• recording, during a long period, candidate signatures liable to be associated with a variation in consumption of one of said items of equipment;
• optionally adding prequalified signatures to said database;
• iteratively changing the parameters of the non-prequalified signatures;
• recording in a reference database the signatures that are most representative of the events related to the functioning of said equipment;
• optionally qualifying each of the signatures recorded in said database with respect to an associated event;
• and
• next using said database of reference signatures for qualifying the events occurring on said network.

A system for analysing the consumption of electricity of a site equipped with a plurality of items of electrical equipment of a different kind, said system comprising:

• at least one sensor for the periodic measurement of the current and/or the voltage on at least one of the electrical phases upstream of the supply network for the site, as well as a computer for performing processing comprising:
• sampling at least the current signal at a frequency at least thirty times greater than the fundamental frequency of the electrical supply voltage;
• applying a Fourier transform to each fundamental period of the current signal at least proceeding with a temporal smoothing of said transformed signal by calculating a temporal mean over a characteristic period of change in behaviour of the equipment in the network wherein said characteristic period of change in behaviour is sufficiently long compared with the carrier period and sufficiently short not to cover several events;
• forming a database of signatures suited to the site being studied during a first implementation step, comprising:
• recording, during a long period, candidate signatures liable to be associated with a variation in consumption of one of said items of equipment;
• optionally adding prequalified signatures to said database;
• iteratively changing the parameters of the non-prequalified signatures;
• recording in a reference database the signatures that are most representative of the events related to the functioning of said equipment;
• optionally qualifying each of the signatures recorded in said database with respect to an associated event;
• and
• next using said database of reference signatures for qualifying the events occurring on said network.