Photovoltaic system power tracking method

• US 9,291,696 B2
• Filed: 12/04/2008
• Issued: 03/22/2016
• Est. Priority Date: 12/05/2007
• Status: Active Grant

• Current Assignee: Solaredge Technologies Incorporated
• Original Assignee: Solaredge Technologies Incorporated
• Inventors: Adest, Meir, Handelsman, Lior, Galin, Yoav, Fishelov, Amir, Sella, Guy
• Primary Examiner(s): Johnson, Jonathan
• Assistant Examiner(s): BERNIER, LINDSEY A
• Application Number:
  US12/314,113
• Publication Number:
  US 20090145480A1
• Time in Patent Office: 2,665 Days
• Field of Search: 136/244, 136/246, 136/252, 136/259, 136/293
• US Class Current: 1/1
• CPC Class Codes: G01S 3/7861 Solar tracking systems
• CPC Class Codes: H02J 2300/26 involving maximum power point tracking control for photovoltaic sources maximum power point systems in particular G05F1/67
• CPC Class Codes: H02J 3/381 Dispersed generators
• CPC Class Codes: H02J 3/388 Islanding, i.e. disconnection of local power supply from the network
• CPC Class Codes: H02J 3/46 Controlling of the sharing of output between the generators, converters, or transformers
• CPC Class Codes: H02M 1/0077 Plural converter units whose outputs are connected in series
• CPC Class Codes: H02M 7/44 by static converters
• CPC Class Codes: H02M 7/493 the static converters being arranged for operation in parallel
• CPC Class Codes: Y02E 10/52 PV systems with concentrators
• CPC Class Codes: Y02E 10/56 Power conversion systems, e.g. maximum power point trackers

Abstract

A photovoltaic system including a photovoltaic cell, and an electronic module connected to the photovoltaic cell. The electronic module is adapted to produce at least one control signal indicative of electrical power being generated by the photovoltaic cells. A tracking controller is adapted to receive the control signal(s) and based on the control signal(s), the controller is adapted to control a tracking motor for adjusting the system so that electrical power generated by the photovoltaic cells is increased. The photovoltaic system may include an optical element, adapted for concentrating solar light onto the photovoltaic cells. The electronic module preferably performs direct current (DC) to direct current (DC) power conversion and maximum power point tracking by electrical power, current, or voltage at either their inputs or their outputs. Alternatively, the tracking controller is configured to also perform maximum power point tracking by increasing to a local maximum electrical power by varying at least one of (i) current or voltage output from the photovoltaic cell or (ii) current or voltage output from the electronic module.

Claims

1. A system comprising:

one or more photovoltaic cells configured to output direct current (DC) power;

an optical element that concentrates light onto the one or more photovoltaic cells;

a light diffuser that increases uniformity of the light concentrated by the optical element over the one or more photovoltaic cells;

control circuitry configured to perform maximum power point tracking of the DC power and measure the DC power output by the one or more photovoltaic cells to produce a control signal; and

a tracking controller configured to receive the control signal, and, based on the control signal, control a tracking motor that modifies at least one of an angular orientation of the one or more photovoltaic cells, an angular orientation of the optical element, and a distance between the optical element and the one or more photovoltaic cells, and

wherein the tracking controller is further configured to, based on the control signal, change a distance between the light diffuser and the one or more photovoltaic cells.

2. The system of claim 1, wherein the control circuitry is configured to:

determine the DC power generated by the one or more photovoltaic cells at an input of the control circuitry; and

increase, based on the determining, the DC power to a local maximum by varying at least one of current and voltage output from the one or more photovoltaic cells.

3. The system of claim 1, wherein the control circuitry is configured to perform the maximum power point tracking independently from the tracking controller performing the controlling of the tracking motor by performing the maximum power point tracking and the control of the tracking motor, respectively, in at least one of a different time domain or a different frequency domain.

4. The system of claim 1, wherein the tracking controller is configured to, based on the control signal, defocus the system such that the distance of the optical element from the one or more photovoltaic cells is changed.

5. The system of claim 1, further comprising:

a plurality of additional photovoltaic cells connected to a respective plurality of additional control circuitries configured to produce a respective plurality of additional control signals based on additional DC power generated by the plurality of additional photovoltaic cells, wherein the tracking controller is configured to select a portion of the respective plurality of additional control signals and control the tracking motor based on the selected portion.

6. The system of claim 5, wherein the tracking controller is configured to reselect different portions of the respective plurality of additional control signals and control the tracking motor based on the different portions.

7. The system of claim 6, wherein the tracking controller is configured to reselect the different portions to vary which cells of the plurality of additional photovoltaic cells receive peak solar energy.

8. The system of claim 1, further comprising a power converter configured to convert power from the one or more photovoltaic cells.

9. The system of claim 8, wherein the power converter and the control circuitry are configured to perform direct current (DC) to direct current (DC) power conversion.

10. The system of claim 1, wherein the performance of the maximum power point tracking comprises changing the DC power generated by the one or more photovoltaic cells to a local maximum by varying at least one of current output from the one or more photovoltaic cells, voltage output from the one or more photovoltaic cells, current output from the control circuitry, and voltage output from the control circuitry.

11. The system of claim 1, wherein the one or more photovoltaic cells are coupled to a receiver.

12. An apparatus comprising:

a power converter;

control circuitry configured to;

receive electrical power generated by one or more photovoltaic cells,

produce a control signal based on the electrical power, and

increase to a local maximum the electrical power generated by the one or more photovoltaic cells by varying at least one of voltage output or current output from the one or more photovoltaic cells; and

a tracking controller configured to;

receive the control signal, and

control, based on the control signal, a tracking motor to change position of an optical element and a distance of a light diffuser relative to the one or more photovoltaic cells such that the electrical power generated by the one or more photovoltaic cells is changed, wherein the optical element concentrates different amounts of light at different positions of the optical element relative to the one or more photovoltaic cells, and wherein the light diffuser changes diffusion of concentrated light onto the one or more photovoltaic cells at different distances of the diffuser relative to the one or more photovoltaic cells.

13. A system comprising:

a plurality of photovoltaic cells configured to output direct current (DC) power;

a plurality of sensors connected to the plurality of photovoltaic cells, wherein the plurality of sensors are configured to generate a plurality of control signals; and

a tracking controller circuitry configured to;

control, based on plurality of control signals, a distance of a light diffuser relative to the plurality of photovoltaic cells and at least one of an angular orientation of the plurality of photovoltaic cells, an angular orientation of an optical element, and a distance between the optical element and the plurality of photovoltaic cells.

14. The system of claim 13,

wherein the plurality of control signals includes at least one voltage control signal and at least one current control signal, and wherein the tracking controller circuitry is configured to select a portion of the plurality of control signals and configured to control, based on the selected portion, at least one of the angular orientation of the plurality of photovoltaic cells, the angular orientation of an optical element, the distance between the optical element and the plurality of photovoltaic cells, and the distance of the light diffuser.

15. The system of claim 14, wherein the tracking controller circuitry is configured to reselect different portions of the plurality of control signals and configured to control, based on the different portions, at least one of the angular orientation of the plurality of photovoltaic cells, the angular orientation of an optical element, the distance between the optical element and the plurality of photovoltaic cells, and the distance of the light diffuser.

16. The system of claim 15, wherein the tracking controller circuitry is configured to reselect the different portions of the plurality of control signals to vary which photovoltaic cells of the plurality of photovoltaic cells receives peak solar energy.

17. The system of claim 13,

wherein the optical element is configured to concentrate light onto the plurality of photovoltaic cells, and

wherein the light diffuser is configured to diffuse the concentrated light uniformly onto the plurality of photovoltaic cells.