Metering optimal sampling

1. A method comprising:

receiving, by a computing device, voltage information from each metering device of a plurality of sites, each metering device metering power distributed to each of the plurality of sites by at least one controller;

sorting, by the computing device, the plurality of sites based on a statistical value of the voltage information for each of the plurality of sites to create a sorted list of the plurality of sites;

selecting, by the computing device, a subset of sites from the sorted list of the plurality of sites;

generating, by the computing device, a control signal using the voltage information of the selected subset of sites; and

providing, by the computing device, the control signal to the at least one controller.

2. The method of claim 1 , further comprising:

determining, by the computing device based on the voltage information for each of the plurality of sites, a number of metering devices to use to generate the control signal; and

selecting the number of metering devices to form the subset of sites.

3. The method of claim 1 , further comprising:

selecting, by the computing device, an initial number of metering devices to use to form the subset of sites;

determining, by the computing device, that the initial number of metering devices does not satisfy an error margin;

increasing, by the computing device responsive to determining that the initial number of metering devices does not satisfy the error margin, the initial number of metering devices to an increased number of metering devices;

evaluating, by the computing device, the error margin using the increased number of metering devices to determine that the increased number of metering devices satisfies the error margin; and

selecting the increased number of metering devices to form the subset of sites.

4. The method of claim 3 , further comprising:

increasing, by the computing device, the initial number of metering devices by a predetermined number such that the increased number of metering devices is less than a maximum number of metering devices.

5. The method of claim 3 , wherein the initial number of metering devices comprises a square root of a total number of metering devices.

6. The method of claim 1 , further comprising:

sorting, by the computing device, the plurality of sites in ascending order of the statistical value or descending order of the statistical value; and

selecting, by the computing device, the subset of sites from the sorted list corresponding to a low statistical value.

7. The method of claim 1 , wherein determining the statistical value further comprises:

determining, by the computing device, an expected value of the voltage information for each of the plurality of sites.

8. The method of claim 1 , wherein determining the statistical value further comprises:

determining, by the computing device, a mean value of the voltage information for each of the plurality of sites.

9. The method of claim 1 , wherein the voltage information includes a voltage measurement and a sample time associated with the voltage measurement.

10. The method of claim 1 , further comprising:

determining, by the computing device, a total voltage to the plurality of sites based on the voltage information from each metering device of the plurality of sites;

determining, by the computing device, a first covariance weighted distance for the total voltage to the plurality of sites;

determining, by the computing device, a second covariance weighted distance for each of the plurality of sites based on the voltage information from each of the metering devices; and

determining, by the computing device, a number of metering devices to use to form the subset of sites based on the first covariance weighted distance, the second covariance weighted distance, and a variance difference threshold.

11. The method of claim 10 , wherein the variance difference threshold comprises an error margin for an estimate of a sample-size dependent variance ratio.

12. The method of claim 1 , further comprising:

determining, by the computing device, a median value for each of the plurality of sites based on the voltage information from each of the metering devices; and

selecting, by the computing device, metering devices from the sorted list that have a lowest median value of the voltage information to form the subset.

13. A system, comprising:

a computing device including at least one processor configured to:

receive voltage information from each metering device of a plurality of sites, each metering device metering power distributed to each of the plurality of sites by at least one controller;

sort the plurality of sites based on a statistical value of the voltage information for each of the plurality of sites to create a sorted list of the plurality of sites;

select a subset of sites from the sorted list of the plurality of sites;

generate a control signal using the voltage information of the subset of sites; and

provide the control signal to the at least one controller.

14. The system of claim 13 , wherein the computing device is further configured to:

determine, based on the voltage information for each of the plurality of sites, a number of metering devices to use to generate the control signal to control operation of the at least one controller; and

select the number of metering devices for the subset of sites from the sorted list of the plurality of sites.

15. The system of claim 13 , wherein the computing device is further configured to:

select an initial number of metering devices to use to form the subset of sites;

determine that the initial number of metering devices does not satisfy an error margin;

increase responsive to determining that the initial number of metering devices does not satisfy the error margin, the initial number of metering devices to an increased number of metering devices;

evaluate the error margin using the increased number of metering devices to determine that the increased number of metering devices satisfies the error margin; and

select the increased number of metering devices to form the subset of sites.

16. The system of claim 15 , wherein the computing device is further configured to:

increase the initial number of metering devices by a predetermined number such that the increased number of metering devices is less than a maximum number of metering devices.

17. The system of claim 13 , wherein the computing device is further configured to:

sort the plurality of sites in ascending order of the statistical value or descending order value of the statistical value; and

select the subset of sites corresponding to a low statistical value.

18. The system of claim 13 , wherein the computing device is further configured:

determining an expected value of the voltage information for each of the plurality of sites.

19. The system of claim 13 , the computing device is further configured to:

determine a total voltage to the plurality of sites based on the voltage information from each metering device of the plurality of sites;

determine a first covariance weighted distance for the total voltage to the plurality of sites;

determine a second covariance weighted distance for each of the plurality of sites based on the voltage information from each of the metering devices; and

determine a number of metering devices to use for the subset based on the first covariance weighted distance, the second covariance weighted distance, and a variance difference threshold.

20. The system of claim 13 , the computing device is further configured to:

determine a median value for each of the plurality of sites based on the voltage information from each of the metering devices; and

select metering devices from the sorted list that have a lowest median value of the voltage information to form the subset of sites.