METHOD AND APPARATUS FOR INDICATING A DISCONNECTION WITHIN A DISTRIBUTED GENERATOR

• US 20110273302A1
• Filed: 04/18/2011
• Published: 11/10/2011
• Est. Priority Date: 04/16/2010
• Status: Active Grant

• Current Assignee: Enphase Energy Incorporated
• Original Assignee: Enphase Energy Incorporated
• Inventors: BELUR, RAGHUVEER R., FORNAGE, MARTIN
• Granted Patent: US 8,749,395 B2
• Time in Patent Office: Days
• US Class Current: 340/635
• CPC Class Codes: G01R 31/50 Testing of electric apparatus, lines, cables or components for short-circuits, continuity, leakage current or incorrect line connections testing of sparking plugs H01T13/58
• CPC Class Codes: G01R 31/52 Testing for short-circuits, leakage current or ground faults
• CPC Class Codes: G01R 31/54 Testing for continuity
• CPC Class Codes: H01L 31/02021 for solar cells electrical connection means, e.g. junction boxes, specially adapted for structural association with photovoltaic modules H02S40/34
• CPC Class Codes: H02J 2300/24 of photovoltaic origin
• CPC Class Codes: H02J 3/381 Dispersed generators
• CPC Class Codes: Y02E 10/56 Power conversion systems, e.g. maximum power point trackers

Abstract

A method and apparatus for indicating a disconnection within a Distributed Generator (DG). In one embodiment, the apparatus comprises an alarm module electrically coupled to a conductive portion of a component within the DG, wherein the conductive portion is grounded via a ground rod system, and wherein the alarm module (i) is further coupled to a ground line, (ii) couples a monitoring current to the conductive portion, (iii) monitors flow of the monitoring current to determine a change in the flow, and (iv) generates, as a result of the change in the flow, a notification of the disconnection.

Claims

1. Apparatus for indicating a disconnection within a Distributed Generator (DG), comprising:

an alarm module electrically coupled to a conductive portion of a component within the DG, wherein the conductive portion is grounded via a ground rod system, and wherein the alarm module (i) is further coupled to a ground line, (ii) couples a monitoring current to the conductive portion, (iii) monitors flow of the monitoring current to determine a change in the flow, and (iv) generates, as a result of the change in the flow, a notification of the disconnection.

2. The apparatus of claim 1, wherein the alarm module communicates the notification to a controller of the DG.

3. The apparatus of claim 2, wherein the alarm module communicates a periodic heartbeat signal to the controller, and wherein the controller generates an alert upon at least one of receiving the notification or cessation of the heartbeat signal.

4. The apparatus of claim 1, wherein the notification indicates at least one of (a) the component is physically disconnected from the DG or (b) a potential ground disconnection safety issue.

5. The apparatus of claim 1, wherein the alarm module is continuously powered by at least one of the DG or a commercial power grid.

6. The apparatus of claim 1, wherein the monitoring current is on the order of 1.0 milliamp.

7. The apparatus of claim 1, wherein the component is a photovoltaic module.

8. A method for indicating a disconnection within a Distributed Generator (DG), comprising:

coupling a monitoring current to a conductive portion of a component within the DG, wherein the conductive portion is grounded via a ground rod system;

monitoring flow of the monitoring current to determine a change in the flow; and

generating, as a result of the change in the flow, a notification of the disconnection.

9. The method of claim 8, further comprising communicating the notification to a controller of the DG.

10. The method of claim 8, further comprising communicating a periodic heartbeat signal and generating, upon cessation of the heartbeat signal, an alert.

11. The method of claim 8, wherein the notification indicates at least one of (a) the component is physically disconnected from the DG or (b) a potential ground disconnection safety issue.

12. The method of claim 8, further comprising continuously powering the alarm module by at least one of the DG or a commercial power grid.

13. The method of claim 8, wherein the monitoring current is on the order of 1.0 milliamp.

14. The method of claim 8, wherein the component is a photovoltaic module.

15. A system for indicating a disconnection within a Distributed Generator (DG), comprising:

a photovoltaic (PV) module comprising a conductive frame, wherein the conductive frame is grounded via a ground rod system; and

an alarm module, wherein the alarm module (i) is electrically coupled to the conductive frame and to a ground line, (ii) couples a monitoring current to the conductive frame, (iii) monitors flow of the monitoring current to determine a change in the flow, and (iv) generates, as a result of the change in the flow, a notification of the disconnection.

16. The system of claim 15, further comprising a controller communicatively coupled to the alarm module, wherein the alarm module communicates the notification to the controller.

17. The system of claim 16, wherein the alarm module communicates a periodic heartbeat signal to the controller, and wherein the controller generates an alert upon at least one of receiving the notification or cessation of the heartbeat signal.

18. The system of claim 15, wherein the notification indicates at least one of (a) the PV module is physically disconnected from the DG or (b) a potential ground disconnection safety issue.

19. The system of claim 15, wherein the alarm module is continuously powered by at least one of the DG or a commercial power grid.

20. The system of claim 15, wherein the monitoring current is on the order of 1.0 milliamp.