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

Patent metadata

Field	Value
Publication number	US-2016349310-A1
Application number	US-201514722412-A
Country	US
Kind code	A1
Filing date	May 27, 2015
Priority date	May 27, 2015
Publication date	Dec 1, 2016
Grant date	—

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 a wiring configuration of an electric power system, comprising:
determining a plurality of Line to Line voltage measurement values for the electric power system; determining a voltage ratio for the electric power system using a plurality of the Line to Line voltage measurement values; and using the voltage ratio to determine 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 a 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, comprising:
a control system, wherein the control system stores and is structured to execute a number of routines, the number of routines being structured to:
determine a plurality of Line to Line voltage measurement values for the electric power system,
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 a wiring configuration of the electric power system.

10 . The branch circuit meter module according to claim 9 , wherein the routines are structured 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 to determine a plurality of Line to Line voltage measurement values by: (i) obtaining in a 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 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 to determine the plurality of Line to Line voltage measurement values by determining a plurality of Line to Neutral voltage measurement values for the electric power system, wherein the routines are further structured to determine a second V max , where the second V max is a maximum of the Line to Neutral voltage measurement values, determine a second V min , where the second V min is a minimum of the Line to Neutral voltage measurement values, determine a second voltage ratio equal to the second V min /the second V max , and use 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.

15 . The branc

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

• G01R22/10

  using digital techniques · CPC title

• G01R19/2513

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

• G01R31/42 Primary

  AC power supplies · CPC title