Method for the real-time estimation of the total consumption of a fluid distributed to users, and a distribution network implementing said method
A method for the real-time estimation of the total consumption of a fluid, in particular water or gas, distributed from a unit (A) to users (b 1 , b 2 . . . ) via a network of supply pipes (E) with a branch (d 1 , d 2 . . . ), for each user, fitted with a counter (c 1 , c 2 . . . ) of the fluid consumed by the user, which method involves defining cohorts of users having homogeneous behavior with regard to the consumption of fluid; defining, for at least one of these cohorts, a sample of users from the cohort that is statistically sufficient to represent the cohort; fitting only the branches of the users of each sample with a remote reading device (t 1 , t 2 , . . . ) for reading the consumption; also fitting remote reading devices to the branches of the users of the other cohorts that have not been sampled; and processing the information provided by the remote reading devices to obtain a real-time value representative of the total consumption of the network.
1. A method for estimating in real time a total consumption of a fluid, the method comprising:
distributing the fluid from a unit to users via a network of supply pipes having a branch for each user, each branch equipped with a meter for the fluid consumed by the user,
determining cohorts of users, each cohort of users comprising a number of users having a homogeneous behavior concerning the consumption of fluid,
determining, for at least one of the cohorts, a sample of users which is less than a total number of users in the respective cohort and is statistically sufficient to represent the respective cohort, wherein:
only the branches for the sample of users of the at least one of the cohorts are equipped with a remote reading device for reading the consumption, and
one or more of the branches for the users in cohorts other than the at least one of the cohorts are also equipped with remote reading devices, and
processing information provided by the remote reading devices to obtain in real time a value representative of the total consumption of the network,
wherein all the branches of users in an upper cohort of the cohorts, which corresponds to a highest consumption among the cohorts, are equipped with remote reading devices, while the cohorts other than the upper cohort, which correspond to consumptions above a null value, have fewer than all the branches sampled, with only the branches sampled being equipped with remote reading devices, and
wherein ‘n’ denotes the total number of users of all the cohorts to be sampled, a size n h of the sample of users within a sampled cohort h within the at least one of the cohorts is effected according to a Neyman allocation according to which the size n h depends on a headcount N h of the sampled cohort and on a square root S h of a dispersion within the sampled cohort:
n
h
=
n
′
×
N
h
S
h
∑
h
=
1
L
-
1
N
h
S
h
with L-1 equal to a number of cohorts sampled.
2. The method as claimed in claim 1 , wherein the cohorts of users are determined on the basis of a period of consumption of a plurality of months or a year and each cohort combines the users for whom the consumption over the considered period is between two predetermined consumption limits.
3. The method as claimed in claim 1 , wherein the number of cohorts and the number of users in a sample are determined in accordance with a required precision by application of statistical rules.
4. The method as claimed in claim 1 , wherein the number of cohorts is equal to six, with one cohort of null consumption.
5. The method as claimed in claim 1 , wherein indices of consumption provided by the remote reading devices are fitted at fixed hour by interpolation.
6. The method as claimed in claim 1 , wherein a composition of the cohorts is rectified by periodically updated information related to the consumption of the users.
7. The method as claimed in claim 1 , wherein collected data is processed to eliminate outliers, to reconstitute missing data by interpolation or extrapolation and to determine the total consumption.
8. The fluid distribution network employing a method as claimed in claim 1 , this network comprising a set of pipes supplied by a unit and branches equipped with meters to deliver to the users the fluid to be consumed, some of these branches being equipped with remote reading devices, wherein the remote reading devices, the number of which is less than the number of meters, are distributed taking into account a consumption of each user, a probability of a branch being equipped with a remote reading device being in direct proportion to the consumption of the user connected to that branch.
9. The fluid distribution network as claimed in claim 8 , wherein the number of branches equipped with remote reading devices is less than or equal to 20%, notably approximately 10% of the total number of branches, and the remote reading devices are distributed in accordance with the consumption of each user sample so that the total consumption estimated with this limited number of remote reading devices is reliable to within about 10%.