Market-adaptive detection of plug-in electric vehicle charging using whole house energy metering data

• US 9,889,759 B1
• Filed: 10/31/2014
• Issued: 02/13/2018
• Est. Priority Date: 05/12/2014
• Status: Active Grant

• Current Assignee: Sacramento Municipal Utility District
• Original Assignee: Sacramento Municipal Utility District
• Inventors: Aswani, Deepak Jayanti, Toyama, Nathan, Boyce, William David
• Primary Examiner(s): Chein, Allen C
• Application Number:
  US14/530,352
• Time in Patent Office: 1,201 Days
• Field of Search: None
• CPC Class Codes: B60L 2240/70 Interactions with external data bases, e.g. traffic centres
• CPC Class Codes: B60L 2240/80 Time limits
• CPC Class Codes: B60L 53/14 Conductive energy transfer
• CPC Class Codes: B60L 53/63 in response to network capacity
• CPC Class Codes: B60L 53/64 Optimising energy costs, e.g. responding to electricity rates
• CPC Class Codes: B60L 53/65 involving identification of vehicles or their battery types
• CPC Class Codes: B60L 53/665 Methods related to measuring, billing or payment
• CPC Class Codes: B60L 53/68 Off-site monitoring or control, e.g. remote control
• CPC Class Codes: G01R 21/133 by using digital technique
• CPC Class Codes: G06Q 20/145 Payments according to the detected use or quantity
• CPC Class Codes: G06Q 50/06 Energy or water supply
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• CPC Class Codes: Y02T 90/12 Electric charging stations
• CPC Class Codes: Y02T 90/14 Plug-in electric vehicles

Abstract

The invention provides improved methods for detecting the presence of a plug-in electric vehicle (PEV) at a location based on interval measurements from whole house electrical meters. This methodology is applicable to multiple detection algorithms and has been validated using actual PEV customer data.

Claims

1. A computer-implemented method for detecting plug-in electrical vehicle (PEV) charging at a whole house electrical meter location, comprising the steps of:

providing a plurality of whole house electrical meters, wherein each whole house electrical meter is located at a particular whole house electrical meter location, and provides input data regarding that particular whole house electrical meter location;

retrieving the input data from a tangible computer memory, said input data including (i) whole house meter interval data for a single whole house meter location to be tested and (ii) whole house meter interval data for a superset of whole house meter locations;

calculating time-referenced summary statistics comprising one or both of the means and standard deviations for the whole house meter interval data for the superset;

selecting a time period for testing a location for PEV charging;

generating a SINGLE HOME MATRIX which is a matrix of whole house meter interval data to be tested;

generating one or both of;

a MEAN MATRIX which is a matrix of corresponding interval means from the superset, and

a STANDARD DEVIATION MATRIX which is a matrix of corresponding interval standard deviations from the superset;

normalizing the SINGLE HOME MATRIX using one or both of the MEAN MATRIX and the STANDARD DEVIATION MATRIX to generate a NORMALIZED MATRIX;

applying a binary hypothesis test to the NORMALIZED MATRIX to obtain a determination of whether PEV charging is present at the single whole house meter location;

and

storing a record of the determination in tangible computer memory.

2. The computer-implemented method of claim 1, wherein the superset of whole house meter locations is selected from the group consisting of the whole population of whole house meter locations.

3. The computer-implemented method of claim 1, wherein the superset of whole house meter locations is a subgroup of the whole population of whole house meter locations.

4. The computer-implemented method of claim 3, wherein the subgroup is a subgroup of the whole population of whole house meter locations based on one or more of geographical location, type of home and demographics.

5. The computer-implemented method of claim 1, wherein the step of normalizing the SINGLE HOME MATRIX to generate a NORMALIZED matrix, comprises:

element-wise subtraction of the MEAN MATRIX from the SINGLE HOME MATRIX to obtain element-wise differences; and

/or

element-wise division of the element-wise differences by the STANDARD DEVIATION MATRIX to obtain element-wise results that are assigned to the NORMALIZED MATRIX.

6. The computer-implemented method of claim 1, wherein the interval data is hourly interval data.

7. The computer-implemented method of claim 1, wherein the period selected to be tested is a 24-hour period.

8. The computer-implemented method of claim 1, wherein the method is performed for each of a plurality of single whole house meter locations in the superset to be tested.

9. The computer-implemented method of claim 1, wherein the detection algorithm is selected from the group consisting of the Likelihood Ratio Test and Support Vector Machine classification.

10. The computer-implemented method of claim 1, further comprising the steps of:

for a whole house meter location for which a determination is made that PEV charging is present, assigning a reduced billing rate for at least some electrical power consumption at that whole house meter location; and

/or

performing a distribution infrastructure load assessment based at least in part on the detection of PEV charging at whole house meter locations according to the method.

11. The computer-implemented method of claim 10, wherein the method comprises the step of:

for a whole house meter location for which a determination is made that PEV charging is present, assigning a reduced billing rate for at least some electrical power consumption at that whole house meter location, and

the reduced billing rate is assigned only for a period in which PEV charging is detected according to the method.

12. A computer-implemented method for detecting plugin electrical vehicle (PEV) charging at a whole house electrical meter location using a Support Vector Machine (SVM) algorithm, comprising the steps of:

providing a plurality of whole house electrical meters, wherein each whole house electrical meter is located at a particular whole house electrical meter location, and provides input data regarding that particular whole house electrical meter location;

retrieving the input data from a tangible computer memory, said input data including (i) whole house meter interval data for a single whole house meter location to be tested and (ii) whole house meter interval data for a superset of whole house meter locations;

calculating time-referenced summary statistics comprising the means for the whole house meter interval data for the superset;

selecting a time period for testing a location for PEV charging;

generating a SINGLE HOME MATRIX which is a matrix of whole house meter interval data to be tested (x);

generating a TEMPORAL SEGMENTATION MATRIX which is a matrix of corresponding interval means from the superset (n);

selecting a NOMINAL DAY MODEL MATRIX of whole house meter interval data from a set of parameterized matrices with no PEV charging based on what matrix has the smallest norm (i.e. Euclidean/L2 norm) of difference with respect to the TEMPORAL SEGMENTATION MATRIX (so NOMINAL DAY MODEL MATRIX*

H=TEMPORAL SEGMENTATION MATRIX, but for an infinite set of matrices, NOMINAL DAY MODEL MATRIX=\i=TEMPORAL SEGMENTATION MATRIX);

generating a PEV DAY MODEL MATRIX of whole house meter interval data that is the element-wise sum of the NOMINAL DAY MODEL MATRIX plus a predetermined sequence of PEV charging load that is typical for the time period selected (n+Xi);

calculating the norm for the difference of SINGLE HOME MATRIX minus NOMINAL DAY MODELMATRIX (i.e. Euclidian/L2 norm) and then taking the reciprocal, assigned to NULL (=1/∥

x−

\i∥

);

calculating the norm for the difference of SINGLE HOME MATRIX minus PEV DAY MODELMATRIX (i.e. Euclidian/L2 norm) and then taking the reciprocal, assigned to ALTERNATE (=1/1|x−

(n+Xi)∥

=1/∥

x−

n−

Xi∥

);

dividing ALTERNATE by NULL to obtain a RATIO value;

making the determination that if the RATIO value is greater than a preselected calibration parameter, then a PEV is detected, else no PEV is detected for the selected single whole house meter location during the time period being tested; and

storing a record of the determination in tangible computer memory.

13. The computer-implemented method of claim 12, wherein the superset of whole house meter locations is selected from the group consisting of the whole population of whole house meter locations.

14. The computer-implemented method of claim 12, wherein the superset of whole house meter locations is a subgroup of the whole population of whole house meter locations.

15. The computer-implemented method of claim 14, wherein the subgroup is a subgroup of the whole population of whole house meter locations based on one or more of geographical location, type of home and demographics.

16. The computer-implemented method of claim 12, wherein the interval data is hourly interval data.

17. The computer-implemented method of claim 12, wherein the period selected to be tested is a 24-hour period.

18. The computer-implemented method of claim 12, wherein the method is performed for each of a plurality of single whole house meter locations in the superset to be tested.

19. The computer-implemented method of claim 12, further comprising the step of:

for a whole house meter location for which a determination is made that PEV charging is present, assigning a reduced billing rate for at least some electrical power consumption at that whole house meter location; and

/or

performing a distribution infrastructure load assessment based at least in part on the detection of PEV charging at whole house meter locations according to the method.

20. The computer-implemented method of claim 19, wherein the method comprises the step of:

for a whole house meter location for which a determination is made that PEV charging is present, assigning a reduced billing rate for at least some electrical power consumption at that whole house meter location, and

the reduced billing rate is assigned only for a period in which PEV charging is detected according to the method.

21. A computer-implemented method for detecting plugin electrical vehicle (PEV) charging at a whole house electrical meter location using a Likelihood Ration Test (LRT) algorithm, comprising the steps of:

providing a plurality of whole house electrical meters, wherein each whole house electrical meter is located at a particular whole house electrical meter location, and provides input data regarding that particular whole house electrical meter location;

retrieving the input data from a tangible computer memory, said input data including (i) whole house meter interval data for a single whole house meter location to be tested and (ii) whole house meter interval data for a superset of whole house meter locations;

calculating time-referenced summary statistics comprising the means and standard deviations for the whole house meter interval data for the superset;

selecting a time period for testing a location for PEV charging;

generating a SINGLE HOME MATRIX which is a matrix of whole house meter interval data to be tested (x);

generating one or both of;

a MEAN MATRIX which is a matrix of corresponding interval means from the superset (\i), and

a STANDARD DEVIATION MATRIX which is a matrix of corresponding interval standard deviations from the superset (a);

generating a TEMPORAL SEGMENTATION MATRIX which is a concatenated matrix of MEAN MATRIX and STANDARD DEVIATION MATRIX [\i, a];

selecting a joint probability density/mass function from a set of parameterized functions for no PEV charging (null function) based on which function'"'"'s corresponding matrix of concatenated means and standard deviations has the smallest norm (i.e. Euclidean/L2 norm) of difference with respect TEMPORAL SEGMENTATION MATRIX;

generating a joint probability density/mass function for a PEV charging (alternate function) by adding a mean and standard deviation adjustment to the null function which could be as simple as a constant mean offset by charge rate R or a time-weighted offset for mean and standard deviation;

calculating the alternate function value for the SINGLE HOME MATRIX and assign to ALTERNATE HYPOTHESIS;

dividing the ALTERNATE HYPOTHESIS by the NULL HYPOTHESIS to obtain a RATIO value; and

making the determination that if the RATIO value is greater than a preselected calibration parameter, then a PEV is detected, else no PEV is detected for the selected whole house meter location during the time period being tested; and

storing a record of the determination in tangible computer memory.

22. The computer-implemented method of claim 21, wherein the alternate function is

Alternate Hypothesis:

Θ

_1,k(R)=[μ

_k+R,σ

_k,A_k].

23. The computer-implemented method of claim 21, wherein the alternate function is

24. The computer-implemented method of claim 21, wherein the superset of whole house meter locations is selected from the group consisting of the whole population of whole house meter locations.

25. The computer-implemented method of claim 21, wherein the superset of whole house meter locations is a subgroup of the whole population of whole house meter locations.

26. The computer-implemented method of claim 25, wherein the subgroup is a subgroup of the whole population of whole house meter locations based on one or more of geographical location, type of home and demographics.

27. The computer-implemented method of claim 21, wherein the interval data is hourly interval data.

28. The computer-implemented method of claim 21, wherein the period selected to be tested is a 24-hour period.

29. The computer-implemented method of claim 21, wherein the method is performed for each of a plurality of single whole house meter locations in the superset to be tested.

30. The computer-implemented method of claim 21, further comprising the step of:

for a whole house meter location for which a determination is made that PEV charging is present, assigning a reduced billing rate for at least some electrical power consumption at that whole house meter location; and

/or

performing a distribution infrastructure load assessment based at least in part on the detection of PEV charging at whole house meter locations according to the method.

31. The computer-implemented method of claim 21, wherein the method comprises the step of:

for a whole house meter location for which a determination is made that PEV charging is present, assigning a reduced billing rate for at least some electrical power consumption at that whole house meter location, and

the reduced billing rate is assigned only for a period in which PEV charging is detected according to the method.