Systems and methods to balance solar panels in a multi-panel system

• US 10,615,603 B2
• Filed: 10/16/2018
• Issued: 04/07/2020
• Est. Priority Date: 11/26/2008
• Status: Active Grant

• Current Assignee: Tigo Energy, Inc
• Original Assignee: Tigo Energy, Inc
• Inventors: Hadar, Ron, Arditi, Shmuel
• Primary Examiner(s): Kessie, Daniel
• Application Number:
  US16/161,987
• Publication Number:
  US 20190081482A1
• Time in Patent Office: 539 Days
• CPC Class Codes: H02J 2300/26 involving maximum power point tracking control for photovoltaic sources
• CPC Class Codes: H02J 3/38 Arrangements for parallely feeding a single network by two or more generators, converters or transformers
• CPC Class Codes: H02J 3/381 Dispersed generators
• CPC Class Codes: H02J 3/46 Controlling of the sharing of output between the generators, converters, or transformers
• CPC Class Codes: Y02E 10/56 Power conversion systems, e.g. maximum power point trackers

Abstract

Systems and methods to balance currents among a plurality of photovoltaic units connected in series. In aspect, a management unit is coupled between a photovoltaic energy production unit and a string of energy production units. The management unit has an energy storage element (e.g., a capacitor) connected to the photovoltaic energy production unit. The management unit further has a switch to selectively couple to the energy storage element and the photovoltaic energy production unit to the string. The management unit allows the current in the string to be larger than the current in the photovoltaic energy production unit.

Claims

1. A system, comprising:

a management unit, comprising;

a circuit configured to periodically connect and disconnect a solar module to and from a power bus according to a duty cycle, the duty cycle being adjustable to operate the solar module at a maximum power point; and

a controller configured to receive operating parameters from additional management units coupled to the power bus; and

the additional management units, each of the additional management units configured to determine operating parameters of a respective solar module and transmit the operating parameters of the respective solar module to the controller of the management unit, the controller of the management unit further configured to determine duty cycles for the additional management units based at least in part on the operating parameters received from the additional management units.

2. The system of claim 1, comprising the power bus, wherein the power bus is a serial power bus.

3. The system of claim 2, wherein each of the additional management units has a switch to periodically connect and disconnect a respective solar module to and from the power bus.

4. The system of claim 3, wherein the controller of the management unit is configured to determine different phases for respective switches in the additional management units.

5. The system of claim 2, wherein the operating parameters include at least one of:

current, voltage, and temperature.

6. The system of claim 5, wherein the controller of the management unit is configured to calculate estimated maximum power points of solar modules connected on the serial power bus, wherein the duty cycles are determined based on the estimated maximum power points of the solar modules.

7. The system of claim 1, wherein the management unit has only one output to supply electricity generated by the solar module coupled to the circuit.

8. The system of claim 1, wherein the management unit is connected in series with the additional management units of solar modules on the serial power bus.

9. A system, comprising:

a power bus;

a management unit, comprising;

a circuit configured to periodically connect and disconnect a solar module to and from the power bus according to a duty cycle, the duty cycle being adjustable to operate the solar module at a maximum power point; and

a controller configured to receive operating parameters from additional management units coupled to the power bus; and

the additional management units, each of the additional management units configured to determine operating parameters of a respective solar module and transmit the operating parameters of the respective solar module to the controller of the management unit, the controller of the management unit further configured to determine duty cycles for the additional management units based at least in part on the operating parameters received from the additional management units.

10. The system of claim 9, wherein the power bus is a serial power bus.

11. The system of claim 9, wherein each of the additional management units has a switch to periodically connect and disconnect a respective solar module to and from the power bus.

12. The system of claim 11, wherein the controller of the management unit is configured to determine different phases for respective switches in the additional management units.

13. The system of claim 9, wherein the operating parameters include at least one of:

current, voltage, and temperature.

14. The system of claim 13, wherein the controller of the management unit is configured to calculate estimated maximum power points of solar modules connected on the power bus, wherein the duty cycles are determined based on the estimated maximum power points of the solar modules.

15. The system of claim 9, wherein the management unit has only one output to supply electricity generated by the solar module coupled to the circuit.

16. The system of claim 9, wherein the management unit is connected in series with the additional management units on the power bus.

17. A system, comprising:

a management unit, comprising;

a circuit configured to periodically connect and disconnect a solar module to and from a power bus according to a duty cycle, the duty cycle being adjustable to operate the solar module at a maximum power point; and

a controller configured to receive operating parameters from additional management units coupled to the power bus; and

the additional management units, each of the additional management units configured to determine operating parameters of a respective solar module and transmit the operating parameters of the respective solar module to the controller of the management unit, the controller of the management unit further configured to determine duty cycles for the additional management units based at least in part on the operating parameters received from the additional management units, and the management unit being connected in series with the additional management units on the power bus.

18. The system of claim 17, comprising the power bus, wherein the power bus is a serial power bus.

19. The system of claim 17, wherein each of the additional management units has a switch to periodically connect and disconnect a respective solar module to and from the power bus.

20. The system of claim 19, wherein the controller of the management unit is configured to determine different phases for respective switches in the additional management units.