Integrated photovoltaic panel with sectional maximum power point tracking

• US 9,837,556 B2
• Filed: 10/26/2012
• Issued: 12/05/2017
• Est. Priority Date: 10/31/2011
• Status: Active Grant

• Current Assignee: Volterra Semiconductor LLC (Analog Devices, Inc.)
• Original Assignee: Volterra Semiconductor LLC (Analog Devices, Inc.)
• Inventors: Jergovic, Ilija, Yao, Kaiwei, Stratakos, Anthony J.
• Primary Examiner(s): Kessie, Daniel
• Application Number:
  US13/662,166
• Publication Number:
  US 20130106194A1
• Time in Patent Office: 1,866 Days
• Field of Search: None
• CPC Class Codes: H01L 31/0201 comprising specially adapted module bus-bar structures
• 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: H01L 31/0504 specially adapted for series or parallel connection of solar cells in a module
• CPC Class Codes: H02J 2300/26 involving maximum power point tracking control for photovoltaic sources
• 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: H02S 40/32 comprising DC/AC inverter means associated with the PV module itself, e.g. AC modules
• CPC Class Codes: Y02E 10/56 Power conversion systems, e.g. maximum power point trackers

Abstract

An integrated photovoltaic panel has one or more integral DC-DC converter circuits. The DC-DC converter input port couples to a section of at least one photovoltaic (PV) device of the panel separate from PV devices feeding other converters. The converter has an MPPT controller for operating the converter to transfer maximum power from coupled photovoltaic devices to its output port. The PV panel has a transparent substrate to which PV devices are mounted. A laminating material seals PV devices and converters to the substrate. In embodiments, the panel has multiple converters connected with output ports in series. The integrated PV panel provides summed maximum powers of each section of PV devices. In some embodiments the DC-DC converters are complete with inductors, in other embodiments a common inductor is shared by multiple converters of the panel, in a particular embodiment the common inductor is parasitic inductance of the panel.

Claims

1. An integrated photovoltaic panel, comprising:

a substrate;

a plurality of sections disposed on the substrate, each of the plurality of sections including;

a respective electric circuit carrier,

a respective DC-DC converter including (a) a switching device, a freewheeling device, and a control unit disposed on the electric circuit carrier of the section, an (b) input port, and (c) an output port, and

a respective photovoltaic portion including one or more interconnected photovoltaic (PV) cell units electrically coupled to the input port of the DC-DC converter of the section;

a shared bus bar having opposing first and second ends, the first end of the shared bus bar being physically and electrically connected to a bonding area of the electric circuit carrier of a first section of the plurality of sections such that the first end is electrically coupled to the input port of the DC-DC converter of the first section, the second end of the shared bus bar being physically and electrically coupled to a bonding area of the electric circuit carrier of a second section of the plurality of sections such that the second end is electrically coupled to the output port of the DC-DC converter of the second section, and a portion of the shared bus bar between the first and second ends of the shared bus bar being physically and electrically connected to the photovoltaic portion of the first section of the plurality sections; and

material sealing each PV cell unit and each DC-DC converter to the substrate;

wherein;

output ports of the DC-DC converters of a first subset of the plurality of sections are electrically coupled in series to form a first group of sections,

output ports of the DC-DC converters of a second subset of the plurality of sections are electrically coupled in series to form a second group of sections,

each of the first and second groups of sections includes at least two sections,

each section of the first group of sections is different from each section of the second group of sections,

the first group of sections is electrically coupled in parallel with the second group of sections, and

the integrated photovoltaic panel further comprises a first enemy storage inductor electrically coupled in series with the first group of sections and a second energy storage inductor electrically coupled in series with the second group of sections.

2. The integrated photovoltaic panel of claim 1, output ports of the DC-DC converters of at least two of the plurality of sections being electrically coupled in series.

3. The integrated photovoltaic panel of claim 1, further comprising an energy storage inductor electrically coupled in series with the output port of the DC-DC converter of at least one of the plurality of sections.

4. The integrated photovoltaic panel of claim 1, wherein parasitic inductance of panel interconnect serves as an energy storage inductor coupled in series with the output port of the DC-DC converter of at least one of the plurality of sections.

5. The integrated photovoltaic panel of claim 1, output ports of the DC-DC converters of at least two of the plurality of sections being electrically coupled in parallel.

6. The integrated photovoltaic panel of claim 1, the plurality of sections being disposed in a single column.

7. The integrated photovoltaic panel of claim 1, a first subset of the plurality of sections being disposed in a first column, a second subset of the plurality of sections being disposed in a second column, the second column being different from the first column.

8. The integrated photovoltaic panel of claim 7, the plurality of sections comprising a third section in the first column and a fourth section in the second column, the third and fourth sections being in a common row, the DC-DC converter of the third section and the DC-DC converter of the fourth section being part of a common assembly.

9. The integrated photovoltaic panel of claim 8, the DC-DC converter of the third section and the DC-DC converter of the fourth section sharing a common circuit board.

10. The integrated photovoltaic panel of claim 1, wherein:

each one of the plurality of sections has a rectangular shape with opposing first and second corners; and

in each one of the plurality of sections;

a positive output node of the output port of the section extends to the first corner, and

a negative output node of the output port of the section extends to the second corner.

11. The integrated photovoltaic panel of claim 10, the plurality of sections being disposed such that at least one first corner is adjacent to at least one second corner.

12. The integrated photovoltaic panel of claim 11, further comprising a busbar adapted to:

extend the positive output node of one of the plurality of sections to the first corner of the section; and

connect the output port of the section to the output port of an adjacent one of the plurality of sections.

13. The integrated photovoltaic panel of claim 11, further comprising a busbar adapted to:

extend the negative output node of one of the plurality of sections to the second corner of the section; and

connect the output port of the section to the output port of an adjacent one of the plurality of sections.

14. The integrated photovoltaic panel of claim 10, the plurality of sections being disposed such that each first corner is adjacent to a respective second corner.

15. The integrated photovoltaic panel of claim 14, the plurality of sections comprising at least three sections disposed such that some of the first corners are adjacent to two second corners.

16. The integrated photovoltaic panel of claim 15, the plurality of sections being disposed in two different columns such that at least one first corner is adjacent to a second corner in each of the two different columns.

17. The integrated photovoltaic panel of claim 14, each one of the plurality of sections having a first side bounded by the first and second corners of the section, wherein:

a first subset of the plurality are sections are disposed such that the first side of each section of the first subset is oriented according to a first axis;

a second subset of the plurality are sections are disposed such that the first side of each section of the second subset is oriented according to a second axis;

a third subset of the plurality are sections are disposed such that the first side of each section of the third subset is oriented according to a third axis;

a fourth subset of the plurality are sections are disposed such that the first side of each section of the fourth subset is oriented according to a fourth axis;

the first axis is parallel to but offset from the second axis;

the third axis is parallel to but offset from the fourth axis; and

the first and second axes are perpendicular to the third and fourth axes.

18. The integrated photovoltaic panel of claim 1, each DC-DC converter comprising a respective converter assembly, at least some of the plurality of sections occupying a rectangular space upon the substrate such that converter assemblies of the DC-DC converters of the sections are adjacent a first side of the rectangular space.

19. The integrated photovoltaic panel of claim 1, each DC-DC converter comprising first, second, and third terminals collectively forming the input and output ports of the DC-DC converter.

20. The integrated photovoltaic panel of claim 19, the first and second terminals being input terminals, and the first and third terminals being output terminals.

21. The integrated photovoltaic panel of claim 20, wherein each DC-DC converter is configured such that:

the first terminal of the DC-DC converter is a combined negative input terminal and negative output terminal;

the second terminal of the DC-DC converter is a positive input terminal; and

the third terminal of the DC-DC converter is a positive output terminal.

22. The integrated photovoltaic panel of claim 20, wherein each DC-DC converter is configured such that:

the first terminal of the DC-DC converter is a combined positive input terminal and positive output terminal;

the second terminal of the DC-DC converter is a negative input terminal; and

the third terminal of the DC-DC converter is a negative output terminal.

23. The integrated photovoltaic panel of claim 20, wherein each DC-DC converter is configured such that:

the first terminal of the DC-DC converter is a combined negative input terminal and positive output terminal;

the second terminal of the DC-DC converter is a positive input terminal; and

the third terminal of the DC-DC converter is a negative output terminal.

24. The integrated photovoltaic panel of claim 20, the first terminal of the DC-DC converter of the first section being electrically coupled to the third terminal of the DC-DC converter of the second section.

25. The integrated photovoltaic panel of claim 1, the DC-DC converter of at least one of the plurality of sections adapted to communicate information via one or more interconnects.

26. The integrated photovoltaic panel of claim 25, the one or more interconnects communicatively coupling DC-DC converters of at least two of the plurality of sections.

27. The integrated photovoltaic panel of claim 25, the one or more interconnects communicatively coupling DC-DC converters of at least one of the plurality of sections to a master device.

28. The integrated photovoltaic panel of claim 27, the master device comprising a master DC-DC converter.

29. The integrated photovoltaic panel of claim 27, the master device comprising a panel microcontroller.

30. The integrated photovoltaic panel of claim 25, the one or more interconnects operable to communicatively couple telemetry information.

31. The integrated photovoltaic panel of claim 25, the one or more interconnects operable to communicatively couple DC-DC converter control information.

32. The integrated photovoltaic panel of claim 31, the one or more interconnects operable to communicatively couple DC-DC converter synchronization information.

33. The integrated photovoltaic panel of claim 25, the one or more interconnects adapted to capacitively couple information.

34. The integrated photovoltaic panel of claim 33, the one or more interconnects comprising at least one capacitor integrated in the DC-DC converter of at least one of the plurality of sections.

35. The integrated photovoltaic panel of claim 1, at least one of the plurality of sections including busbars electrically coupling the photovoltaic portion of the section to the DC-DC converter of the section.

36. The integrated photovoltaic panel of claim 1, at least two of the plurality of sections comprising the same number of photovoltaic cell units.

37. The integrated photovoltaic panel of claim 1, at least two of the plurality of sections comprising a different number of photovoltaic cell units.

38. The integrated photovoltaic panel of claim 1, wherein:

the DC-DC converter of the first section is adapted to perform maximum power point tracking (MPPT) on the photovoltaic portion of the first section; and

the DC-DC converter of the second section is adapted to perform MPPT on the photovoltaic portion of the second section.

39. The integrated photovoltaic panel of claim 1, the DC-DC converter of at least one of the plurality of sections being adapted to perform maximum power point tracking on the photovoltaic portion of the respective section.

40. The integrated photovoltaic panel of claim 1, at least one photovoltaic portion comprising:

a first photovoltaic cell unit having opposing top and bottom sides, the first photovoltaic cell unit including;

a first solderable area on the top side, and

a second solderable area on the bottom side;

a first ribbon wire attached to the first solderable area, the first solderable area and the first ribbon wire oriented according to a first axis; and

a second ribbon wire attached to the second solderable area, the second solderable area and the second ribbon wire oriented according to a second axis, the second axis being different from the first axis.

41. The integrated photovoltaic panel of claim 40, the first photovoltaic cell unit further including a third solderable area on the bottom side of the first photovoltaic unit cell, the third solderable area oriented according to the first axis.

42. The integrated photovoltaic panel of claim 40, the first axis being perpendicular to the second axis.

43. The integrated photovoltaic panel of claim 1, the photovoltaic unit cells of at least one photovoltaic portion being electrically coupled in series.

44. The integrated photovoltaic panel of claim 43, the photovoltaic unit cells of at least one photovoltaic portion being electrically coupled in series by ribbon wire.

45. The integrated photovoltaic panel of claim 1, at least one photovoltaic portion comprising:

first and second columns of photovoltaic cell units, each of the columns including one or more photovoltaic cell units electrically coupled in series; and

one or more electrical conductors electrically coupling an end photovoltaic cell unit of the first column to an end photovoltaic cell unit of the second column.

46. The integrated photovoltaic panel of claim 1, the DC-DC converter of at least one of the one or more sections further comprising an output capacitor electrically coupled across the output port of the DC-DC converter.

47. The integrated photovoltaic panel of claim 1, the photovoltaic portion of at least one of the one or more sections comprising a number of photovoltaic cell units selected from the group consisting of six photovoltaic cell units, eight photovoltaic cell units, ten photovoltaic cell units, twelve photovoltaic cell units, twenty photovoltaic cell units and twenty four photovoltaic cell units.

48. The integrated photovoltaic panel of claim 1, the substrate being formed of a material selected from the group consisting of glass and a transparent polymeric material.

49. The integrated photovoltaic panel of claim 1, the material sealing each PV cell unit and each DC-DC converter to the substrate comprising laminating material.

50. The integrated photovoltaic panel of claim 49, the laminating material comprising one or more layers of ethylene vinyl acetate.

51. The integrated photovoltaic panel of claim 1, further comprising a back barrier layer disposed on the material sealing each PV cell unit and each DC-DC converter to the substrate, such that each PV cell unit and each DC-DC converter are disposed between the back barrier layer and the substrate.

52. The integrated photovoltaic panel of claim 51, the back barrier layer comprising polyvinyl fluoride.