Dynamically reconfigurable photovoltaic system

Patent metadata

Field	Value
Publication number	US-9356173-B2
Application number	US-201314014266-A
Country	US
Kind code	B2
Filing date	Aug 29, 2013
Priority date	Aug 31, 2012
Publication date	May 31, 2016
Grant date	May 31, 2016

Abstract

A PV system composed of sub-arrays, each having a group of PV cells that are electrically connected to each other. A power management circuit for each sub-array has a communications interface and serves to connect or disconnect the sub-array to a programmable power grid. The power grid has bus rows and bus columns. A bus management circuit is positioned at a respective junction of a bus column and a bus row and is programmable through its communication interface to connect or disconnect a power path in the grid. As a result, selected sub-arrays are connected by selected power paths to be in parallel so as to produce a low system voltage, and, alternately in series so as to produce a high system voltage that is greater than the low voltage by at least a factor of ten.

First claim

We claim:

1. A dynamically reconfigurable energy harvesting photovoltaic (PV) system comprising:
a plurality of PV energy harvesting sub-arrays wherein each sub-array comprises a group of photovoltaic cells that are electrically connected to each other to generate a voltage at a respective one of a plurality of pairs of sub-array power nodes;
a plurality of power management circuits each having a power input that is coupled to a respective one of the pairs of sub-array power nodes and a communications interface; and
a programmable power grid to which a power output of each of the power management circuits is coupled, the power grid having a plurality of bus rows, a plurality of bus columns, a plurality of bus management circuits each being positioned at a respective junction of a bus column and a bus row, and a harvested energy output node,
wherein each power management circuit is programmable through its communication interface during in-the-field use of the PV system to one of connect and disconnect its respective sub-array to the grid, and each bus management circuit is programmable through its communication interface to one of connect and disconnect a power path in the grid, so that selected sub-arrays are connected by selected power paths to be in parallel so as to produce a low voltage at the harvested energy output node, and, alternately, selected sub-arrays of the system are connected by selected power paths to be in series so as to produce a high voltage that is greater than the low voltage by at least a factor of ten.

2. The system of claim 1 wherein each bus row has a respective plurality of bus group segments that are coupled in a daisy chain manner by some of the bus management circuits, and
wherein each bus column has a respective plurality of bus group segments that are coupled in a daisy chain manner by some of the bus management circuits,
each bus group segment having a respective plurality of bus conductors.

3. The system of claim 2 wherein each bus management circuit is coupled to four adjacent bus group segments, and can be programmed to alternately connect and disconnect to each other a) a bus conductor from one of the four adjacent bus group segments and b) a bus conductor from another one of the four adjacent bus group segments.

4. The system of claim 1 wherein each of the power management circuits has a dc-dc converter coupled between the power input of the bus management circuit and the power grid.

5. The system of claim 1 wherein some of the cells in each sub-array are multi junction cells, wherein each multi junction cell has a plurality of junctions, wherein each of the junctions, or at least one subset of said junctions is independently coupled to a multi-junction power manager circuit associated with the multi junction cell, the system further comprising
an electrical power system controller that is to program the power management circuits of low performing sub-arrays to one of a) disconnect the sub-arrays from the power grid in response to a signal from a multi junction power manager circuit associated with a multi junction cell in each of the sub-arrays that indicates low performance of a multi junction cell in the sub-array, and b) where the multi junction power manager circuit comprises a dc-dc boost voltage converter, connect the low-performing sub-arrays to the power grid through the boost voltage converter,
wherein the controller is to program the power management circuits of high performing sub-arrays to connect the sub-arrays to the power grid in response to a signal from a multi-junction power management circuit associated with a multi junction cell in each of the sub-arrays that indicates high performance of a multi junction cell in the sub-array.

6. The system of claim 1 further comprising:
a communications grid to which the communications interfaces of the power management circuits and bus management circuits are coupled; and
an electrical power system controller that is to program the power and bus management circuits, via the communications grid, to set the high or low voltage at the harvested energy output node.

7. The system of claim 1 wherein each of the sub-arrays is composed of photocells each of which has an active or light detection area that is less than five (5) square millimeters in area, and wherein each of the sub-arrays has at least one thousand photocells and is to produce between 1 volt dc and 1000 volts dc.

8. The system of claim 1 further comprising a communications band decoder that is capacitively coupled to a sub-array power node, to decode information or data from a signal detected by the sub-array, wherein said information or data was embedded by a remote source of light that is illuminating the sub-array.

9. A dynamically reconfigurable energy harvesting photovoltaic (PV) system comprising:
a plurality of sub-arrays wherein each sub-array comprises a group of photovoltaic cells that are electrically connected to each other;
a plurality of power management circuits, wherein each power management circuit of the plurality of power management circuits having a power input that is coupled to a respective sub-array power node of a plurality of sub-array power nodes and a communications interface; and
a programmable power grid to which a power output of each of the power management circuits is coupled, wherein the programmable power grid comprising a plurality of bus rows, a plurality of bus columns, and a plurality of bus management circuits, wherein each bus management circuit of the plurality of bus management circuits is positioned at a respective junction of a bus column of the plurality of bus columns and a bus row of the plurality of bus rows,
wherein each power management circuit is programmable through its communication interface during in-the-field use of the PV system to one of connect or disconnect from its respective sub-array to the programmable power grid, and each bus management circuit is programmable through its communication interface to one of connect or disconnect a power path in the programmable power grid, so that selected sub-arrays are connected by selected power paths in parallel, or in series so as to produce a high voltage that is greater than a low voltage by at least a factor of ten.

10. The dynamically reconfigurable energy harvesting PV system of claim 9 , wherein each bus row comprises a plurality of bus group segments that are coupled in a daisy chain manner by some of the bus management circuits of the plurality of bus management circuits.

11. The dynamically reconfigurable energy harvesting PV system of claim 9 , wherein each bus column comprises a plurality of bus group segments that are coupled in a daisy chain manner by some of the bus management circuits of the plurality of bus management circuits.

12. The dynamically reconfigurable energy harvesting PV system of claim 11 , wherein each bus group segment comprises a plurality of bus conductors.

13. The dynamically reconfigurable energy harvesting PV system of claim 9 , wherein each power management circuit of the plurality of power management circuits has a DC-DC converter coupled between a power input of a bus management circuit of the plurality of bus management circuits and the power grid.

14. The dynamically reconfigurable energy harvesting PV system of claim 9 further comprising: a communications band decoder coupled to a sub-array power node of the plurality of sub-array power nodes.

15. The dynamically reconfigurable energy harvesting PV system of claim 9 , wherein each photovoltaic cell of the group of photovoltaic cells comprises an active region th

Assignees

• Sandia Corp

Inventors

• Okandan Murat
• Nielson Gregory N

Classifications

• H02J7/35

  with light sensitive cells · CPC title

• Y02E10/50

  Photovoltaic [PV] energy · CPC title

• H02J2105/30

  the load networks being external to vehicles, i.e. exchanging power with vehicles · CPC title

• H10F77/955

  for photovoltaic devices · CPC title

• B64G1/443 Primary

  Photovoltaic cell arrays · CPC title