SYSTEMS AND METHOD FOR LIMITING MAXIMUM VOLTAGE IN SOLAR PHOTOVOLTAIC POWER GENERATION SYSTEMS

• US 20110025130A1
• Filed: 09/18/2009
• Published: 02/03/2011
• Est. Priority Date: 07/30/2009
• Status: Active Grant

• Current Assignee: Tigo Energy, Inc
• Original Assignee: Tigo Energy, Inc
• Inventors: Makhota, Maxym, Arditi, Shmuel, Hadar, Ron
• Granted Patent: US 8,102,074 B2
• Time in Patent Office: Days
• US Class Current: 307/80
• 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: Y02E 10/50 Photovoltaic [PV] energy

Abstract

Apparatuses and methods are disclosed for regulating or limiting the voltage output from solar modules connected in series such that the voltage on a string bus connecting those solar modules does not exceed regulatory or safety limitations. This can be accomplished via a controller, local management units (for downconverting solar module voltage output), or a combination of the two.

Claims

1. An energy production system, comprising:

a string bus;

a first solar module connected to the string bus and generating a first voltage;

a second solar module connected to the string bus and generating a second voltage; and

a controller configured to limit at least one of the first or second voltages provided to the string bus.

2. The energy production system of claim 1, further comprising:

a first local management unit coupled between the first solar module and the string bus, and in communication with the controller; and

a second local management unit coupled between the second solar module and the string bus, and in communication with the controller.

3. The energy production system of claim 2, wherein the controller controls the first local management unit and the second local management unit.

4. The energy production system of claim 1, wherein the controller comprises:

a first local management unit coupled between the first solar module and the string bus; and

a second local management unit coupled between the second solar module and the string bus.

5. The energy production system of claim 1, further comprising a switchable connection between:

the first solar module and the string bus; and

the second solar module and the string bus.

6. The energy production system of claim 5, wherein the switchable connection includes one or more transistors.

7. The energy production system of claim 6, wherein:

the first voltage provided to the string bus is controlled via a duty cycle of the one or more transistor of the first local management unit; and

the second voltage provided to the string bus is controlled via a duty cycle of the one or more transistor of the second local management unit.

8. The energy production system of claim 1, wherein the controller prevents a voltage on the string bus from exceeding a predefined limit.

9. An energy production system, comprising:

a string bus;

a solar module connected to the string bus and generating a voltage; and

a controller in communication with the solar module and the string bus, and configured to control the voltage provided to the string bus based on a predicted future voltage as predicted by the controller.

10. The energy production system of claim 9, wherein a connection between the solar module and the string bus can be disconnected via a switch.

11. The energy production system of claim 10, wherein the controller adjusts the duty cycle of the switch.

12. The energy production system of claim 10, wherein the switch is a transistor.

13. The energy production system of claim 9, wherein the predicted future voltage is based on a voltage trend.

14. The energy production system of claim 9, wherein the controller is further configured to limit the voltage provided to the string bus to a default voltage.

15. The energy production system of claim 14, wherein the default voltage is used when the voltage exceeds a voltage threshold.

16. The energy production system of claim 9, wherein the solar module is connected to the string bus via a local management unit.

17. A method comprising:

monitoring a first voltage across a first string bus section connecting a first solar module to a second solar module;

monitoring a second voltage across a second string bus section connecting the second solar module to a voltage output; and

limiting the voltage output by limiting at least one of a voltage of the first solar module and a voltage of the second solar module.

18. The method of claim 17, wherein limiting comprises limiting the at least one voltage of the first solar module or the second solar module when the respective at least one voltage of the first solar module and the second solar module exceeds a voltage threshold.

19. The method of claim 17, wherein the limiting comprises controlling the first voltage by controlling the duty cycle of a first switchable connection coupled between the first solar module and the string bus, and wherein the limiting comprises controlling the second voltage by controlling the duty cycle of a second switchable connection coupled between the second solar module and the string bus.

20. The method of claim 17, wherein the limiting is based on a predicted future voltage.