System and Method for Enhanced Watch Dog in Solar Panel Installations

• US 20190207556A1
• Filed: 03/05/2019
• Published: 07/04/2019
• Est. Priority Date: 11/02/2007
• Status: Active Grant

• Current Assignee: Tigo Energy, Inc
• Original Assignee: Tigo Energy, Inc
• Inventors: Hadar, Ron, Arditi, Shmuel, Bickford, James
• Granted Patent: US 10,686,403 B2
• Time in Patent Office: Days
• CPC Class Codes: G01R 31/00 Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere measuring superconductive properties G01R33/1238; testing or measuring semiconductors or solid state devices during manufacture H01L22/00; testing line transmission systems H04B3/46
• 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 3/38 Arrangements for parallely feeding a single network by two or more generators, converters or transformers
• CPC Class Codes: H02S 50/00 Monitoring or testing of PV systems, e.g. load balancing or fault identification
• CPC Class Codes: H02S 50/10 Testing of PV devices, e.g. of PV modules or single PV cells testing of semiconductor devices during manufacturing H01L22/00
• CPC Class Codes: H04B 2203/5458 Monitor sensor; Alarm systems
• CPC Class Codes: Y02E 10/50 Photovoltaic [PV] energy
• CPC Class Codes: Y02E 10/56 Power conversion systems, e.g. maximum power point trackers

Abstract

A system and method for automated shutdown, disconnect, or power reduction of solar panels. A system of solar panels includes one or more master management units (MMUs) and one or more local management units (LMUs). The MMUs are in communication with the LMUs with the MMUs and LMUs “handshaking” when the system is in operation. The MMUs are connected to one or more controllers which in turn are connected to emergency detection sensors. Upon a sensor detection of an emergency, the associated MMU is notified which in turn instructs associated LMUs to take appropriate action. In the event that communication with the MMUs has been cut off, the LMUs take the initiative to shut down, disconnect, or reduce the output of associated string(s) of solar panels.

Claims

1. A photovoltaic panel, comprising:

at least one photovoltaic cell;

a control unit installed on the photovoltaic panel, the control unit having;

a power converter coupled to the least one photovoltaic cell to receive electric power generated by the at least one photovoltaic cell; and

a controller coupled to the power converter;

wherein the power converter generates a power output of the photovoltaic panel using the electric power generated by the at least one photovoltaic cell;

wherein the controller controls operations of the power converter based on communications with a remote unit that is disposed at a location remote from the control unit;

wherein a sensor is monitored for an anomaly; and

wherein after the sensor detects the anomaly and based on a communication with the remote unit, the controller controls the power converter to shut down or reduce the power output of the photovoltaic panel.

2. The photovoltaic panel of claim 1, wherein the remote unit and the sensor are connected in a network.

3. The photovoltaic panel of claim 1, wherein in response to the anomaly, the communication includes a command to shut down, or a command to disconnect.

4. The photovoltaic panel of claim 1, wherein the communication causes the power converter to shut down the power output of the photovoltaic panel and wait for a restart signal.

5. The photovoltaic panel of claim 1, wherein after the power converter shuts down the power output of the photovoltaic panel, the power converter continues to provide a voltage to power the controller.

6. The photovoltaic panel of claim 1, wherein the power converter includes a switch that shorts the power output of the photovoltaic panel to shut down the power output of the photovoltaic panel.

7. The photovoltaic panel of claim 1, wherein the power converter includes a switch that disconnects a circuit path between an output line of the power converter and an output terminal of the photovoltaic panel to shut down the power output of the photovoltaic panel.

8. The photovoltaic panel of claim 1, wherein the controller causes the power converter to shut down the power output of the photovoltaic panel after a predetermined number of skips of heartbeat signals from the remote unit.

9. The photovoltaic panel of claim 8, wherein when skips of heartbeat signals from the remote unit that are less than the predetermined number, the controller does not cause the power converter to shut down the power output of the photovoltaic panel.

10. A control unit for a photovoltaic panel having at least one photovoltaic cell, the control unit comprising:

a voltage regulator configured to receive electric power generated by the at least one photovoltaic cell of the photovoltaic panel; and

a controller coupled to the voltage regulator;

wherein the voltage regulator is configured to generate a power output of the photovoltaic panel using the electric power received from the at least one photovoltaic cell;

wherein the controller is configured to control operations of the voltage regulator based at least in part on communications with a remote unit disposed at a location remote from the photovoltaic panel, the communications including heartbeat signals from the remote unit; and

wherein, after the controller detects an anomaly in the heartbeat signals from the remote unit, the controller causes the voltage regulator to reduce or shut down the power output of the photovoltaic panel.

11. The control unit of claim 10, wherein the anomaly includes skips of heartbeat signals.

12. The control unit of claim 11, wherein the controller causes the voltage regulator to reduce or shut down the power output of the photovoltaic panel when the anomaly includes a predetermined number of skips of the heartbeat signals.

13. The control unit of claim 12, wherein the controller does not cause the voltage regulator to reduce or shut down the power output of the photovoltaic panel when skips of the heartbeat signals are less than the predetermined number.

14. The control unit of claim 11, wherein the remote unit causes the skips in response to a notification from a sensor or a response to an anomaly query.

15. A method, comprising:

generating, by photovoltaic cells of a photovoltaic panel, electric power; and

converting, by a power converter of the photovoltaic panel, the electric power generated by the photovoltaic cells of the photovoltaic panel into a power output of the photovoltaic panel;

communicating, by a controller of the photovoltaic panel, with a remote unit disposed at a location remote from the photovoltaic panel, including receiving heartbeat signals from the remote unit;

detecting an anomaly in the heartbeat signals from the remote unit; and

reducing, after the anomaly, the power output of the photovoltaic panel.

16. The method of claim 15, wherein the anomaly includes skips of heartbeat signals.

17. The method of claim 16, further comprising:

determining, by the controller, that a count of the skips of heartbeat signals is about a threshold; and

causing the power converter to reduce the power output of the photovoltaic panel.

18. The method of claim 17, further comprising:

disconnecting, responsive to the anomaly, the power output of the photovoltaic panel.

19. The method of claim 15, wherein the communicating further includes:

receiving one or more commands from the remote unit.

20. The method of claim 19, wherein the one or more commands include a command to shut down or a command to disconnect.