Method and apparatus to commission voltage sensors and branch circuit current sensors for branch circuit monitoring systems

Patent metadata

Field	Value
Publication number	US-9897647-B2
Application number	US-201514722412-A
Country	US
Kind code	B2
Filing date	May 27, 2015
Priority date	May 27, 2015
Publication date	Feb 20, 2018
Grant date	Feb 20, 2018

Abstract

A method and apparatus for detecting the wiring configuration of an electric power system based upon a particular voltage ratio that is determined for the electric power system. Also a method and apparatus for diagnosing voltage swap conditions in an electric power system. Finally, a method and apparatus for identifying virtual meters in an electric power system.

First claim

What is claimed is:

1. A method for determining and categorizing a wiring configuration of an electric power system that includes a power source, a busbar coupled to the power source, a branch circuit meter module, and a number of loads coupled to the busbar, comprising:
determining in the branch circuit meter module a plurality of Line to Line voltage measurement values for the electric power system using signals from a number of voltage sensors coupled to the busbar;
determining in the branch circuit meter module a voltage ratio for the electric power system using a plurality of the Line to Line voltage measurement values; and
using the voltage ratio in the branch circuit meter module to determine and categorize the wiring configuration of the electric power system.

2. The method according to claim 1 , wherein the determining the voltage ratio comprises:
determining a V min , where V min is a minimum of the Line to Line voltage measurement values,
determining a V max , where V max is a maximum of the Line to Line voltage measurement values; and
determining the voltage ratio as being equal to V min /V max .

3. The method according to claim 2 , wherein the determining a plurality of Line to Line voltage measurement values comprises:
obtaining in the branch circuit meter module a first phase Line to Neutral voltage measurement value for the electric power system, a second phase Line to Neutral voltage measurement value for the electric power system, and a third phase Line to Neutral voltage measurement value for the electric power system; and
determining a first Line to Line voltage measurement value, a second Line to Line voltage measurement value, and a third Line to Line voltage measurement value, each using two or more of the first phase Line to Neutral voltage measurement value, the second phase Line to Neutral voltage measurement value, and the third phase Line to Neutral voltage measurement value;
wherein V min is a minimum of the first Line to Line voltage measurement value, the second Line to Line voltage measurement value, and the third Line to Line voltage measurement value, and V max is a maximum of the first Line to Line voltage measurement value, the second Line to Line voltage measurement value, and the third Line to Line voltage measurement value.

4. The method according to claim 2 , wherein the using the voltage ratio comprises:
(i) determining that the wiring configuration is a 3-phase configuration if the voltage ratio is greater than a first value;
(ii) determining that the wiring configuration is a single-phase 3-wire configuration if the voltage ratio is less than a second value; and
(iii) determining that the wiring configuration is a 2-phase Wye configuration if the voltage ratio is greater than or equal to the second value and less than or equal to the first value.

5. The method according to claim 4 , wherein the first value is 0.789 and the second value is 0.539.

6. The method according to claim 4 , wherein the determining the plurality of Line to Line voltage measurement values comprises determining a plurality of Line to Neutral voltage measurement values for the electric power system, wherein the method further comprises determining a second V max , where the second V max is a maximum of the Line to Neutral voltage measurement values, determining a second V min , where the second V min is a minimum of the Line to Neutral voltage measurement values, determining a second voltage ratio equal to the second V min /the second V max , and using the second voltage ratio to identify the wiring configuration as Corner-Grounded Delta, 4-wire Delta or 4-wire Wye based on the second voltage ratio.

7. The method according to claim 6 , wherein:
(i) the wiring configuration is identified as Corner-Grounded Delta if the second voltage ratio is less than a third value;
(ii) the wiring configuration is identified as 4-wire Wye if the second voltage ratio is greater than a fourth value; and
(iii) the wiring configuration is identified as 4-wire Delta if the second voltage ratio is greater than or equal to the third value and less than or equal to the fourth value.

8. The method according to claim 7 , wherein the third value is 0.366 and the fourth value is 0.732.

9. A branch circuit meter module for an electric power system that includes a power source, a busbar coupled to the power source, and a number of loads coupled to the busbar, the method comprising:
a control system, wherein the control system stores and is structured and configured to execute a number of routines, the number of routines being structured and configured to:
determine a plurality of Line to Line voltage measurement values for the electric power system using signals from a number of voltage sensors coupled to the busbar,
determine a voltage ratio for the electric power system using a plurality of the Line to Line voltage measurement values; and
use the voltage ratio to determine and categorize a wiring configuration of the electric power system.

10. The branch circuit meter module according to claim 9 , wherein the routines are structured and configured to determine the voltage ratio by:
determining a V min , where V min is a minimum of the Line to Line voltage measurement values;
determining a V max , where V max is a maximum of the Line to Line voltage measurement values; and
determining the voltage ratio as being equal to V min /V max .

11. The branch circuit meter module according to claim 10 , wherein the routines are structured and configured to determine a plurality of Line to Line voltage measurement values by: (i) obtaining in the branch circuit meter module a first phase Line to Neutral voltage measurement value for the electric power system, a second phase Line to Neutral voltage measurement value for the electric power system, and a third phase Line to Neutral voltage measurement value for the electric power system, and (ii) determining a first Line to Line voltage measurement value, a second Line to Line voltage measurement value, and a third Line to Line voltage measurement value, each using two or more of the first phase Line to Neutral voltage measurement value, the second phase Line to Neutral voltage measurement value, and the third phase Line to Neutral voltage measurement value; wherein V min is a minimum of the first Line to Line voltage measurement value, the second Line to Line voltage measurement value, and the third Line to Line voltage measurement value, and V max is a maximum of the first Line to Line voltage measurement value, the second Line to Line voltage measurement value, and the third Line to Line voltage measurement value.

12. The branch circuit meter module according to claim 10 , wherein the routines are structured and configured to use the voltage ratio to determine the wiring configuration by:
(i) determining that the wiring configuration is a 3-phase configuration if the voltage ratio is greater than a first value;
(ii) determining that the wiring configuration is a single-phase 3-wire configuration if the voltage ratio is less than a second value; and
(iii) determining that the wiring configuration is a 2-phase Wye configuration if the voltage ratio is greater than or equal to the second value and less than or equal to the first value.

13. The branch circuit meter module according to claim 12 , wherein the first value is 0.789 and the second value is 0.539.

14. The branch circuit meter module according to claim 12 , wherein the routines are structured and configured to determine the plurality of Line to Line voltage measurement values by determining a plurality of Line to Neutral

Assignees

• Eaton Corp

Inventors

• Hayashi Alan Kenji
• Zaremski Brian Zachary
• Gao Zhi

Classifications

• G01R31/67

  Testing the correctness of wire connections in electric apparatus or circuits · CPC title

• G01R22/06

  by electronic methods · CPC title

• G01R31/42 Primary

  AC power supplies · CPC title

• G01R25/00

  Arrangements for measuring phase angle between a voltage and a current or between voltages or currents · CPC title

• G01R19/2513

  Arrangements for monitoring electric power systems, e.g. power lines or loads; Logging · CPC title