Solar power array with maximized panel power extraction

• US 20100133911A1
• Filed: 12/03/2008
• Published: 06/03/2010
• Est. Priority Date: 12/03/2008
• Status: Active Grant

• Current Assignee: Also Energy Incorporated
• Original Assignee: Solarbridge Technologies Incorporated (Totalenergies Se)
• Inventors: Williams, Bertrand Jeffery, Raymis, Bret Allan
• Granted Patent: US 8,053,929 B2
• Time in Patent Office: Days
• US Class Current: 307/82
• CPC Class Codes: G05F 1/67 to the maximum power available from a generator, e.g. from solar cell
• CPC Class Codes: H02J 2300/24 of photovoltaic origin
• 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: H02M 1/0077 Plural converter units whose outputs are connected in series
• CPC Class Codes: Y02E 10/56 Power conversion systems, e.g. maximum power point trackers

Abstract

A solar power array includes solar power panels, where each solar panel provides output current and voltage, separate DC-DC converters, where each solar panel is connected to a unique DC-DC converter, where each DC-DC converter is designed to maximize the power from each solar panel, and where each DC-DC converter produces a high voltage output, a high voltage DC bus coupled to the DC-DC converters that receives the high voltage output, and a DC-AC inverter that inverts the high voltage DC on the high voltage DC bus to an AC power signal for distribution to one or more AC loads.

Claims

1. A solar power array, comprising:

a plurality of solar power panels, wherein each solar panel provides output current and voltage;

a plurality of separate DC-DC converters, wherein each solar panel is connected to a unique DC-DC converter, wherein each DC-DC converter produces a high voltage output;

a high voltage DC bus coupled to the DC-DC converters that receives the high voltage output; and

a DC-AC inverter that inverts the high voltage DC on the high voltage DC bus to an AC power signal for distribution to one or more AC loads.

2. The solar power array of claim 1, wherein each DC-DC converter comprises:

a sensing circuit to sense current and voltage output of an associated solar panel;

a maximum power point tracking (MPPT) controller, coupled to the sensing circuit, that receives the sensed values of current and voltage and calculates power being delivered by the solar panel to determine adjustments to be made to the solar panel'"'"'s operating conditions; and

a DC-DC switching power module, coupled to the MPPT controller, that receives the determined adjustments and transfers the power to the high-voltage DC bus to achieve a maximum power output from the solar panel.

3. The solar power array of claim 1, wherein the solar panels are series-connected in a string.

4. The solar power array of claim 3, wherein an output port of the DC-DC converter comprises a current equalizing circuit constituting an effective virtual power point that ensures the DC-DC converter operates in an equivalent of an output current mode.

5. The solar power array of claim 4, wherein the DC-DC converter output current is dynamically maintained within optimal boundary conditions.

6. The solar power array of claim 3, wherein the output port of the DC-DC converter comprises a voltage balancing circuit constituting an effective virtual power port, wherein the string of series-connected solar panels is connected in parallel with other strings of series-connected solar panels, and wherein a sum of the solar panel voltages is relatively equivalent across the parallel-connected strings, by virtue of the voltage balancing.

7. The solar power array of claim 6, wherein the DC-DC converter output voltage is dynamically maintained within optimal boundary conditions.

8. The solar power array of claim 2, wherein the DC-DC converter comprises a switching power supply SEPIC circuit architecture to transfer power to the output.

9. The solar power array of claim 2, wherein the DC-DC converter comprises a switching power supply active clamped forward circuit architecture to transfer power to the output.

10. The solar power array of claim 2, wherein the solar panels are parallel-connected.

11. The solar power array of claim 10, wherein an output port of the DC-DC converter comprises a virtual power port having a voltage balancing circuit to ensure the DC-DC converter operates at a relatively equivalent output voltage mode.

12. The solar power array of claim 11, wherein the DC-DC converter'"'"'s output voltages and currents are dynamically maintained within optimal boundary conditions.

13. The solar power array of claim 12, wherein the DC-DC converter comprises a switching power supply boost circuit to transfer power to the output.

14. The solar power array of claim 12, wherein the DC-DC converter comprises a switching power supply active clamp forward circuit to transfer power to the output.

15. The solar power array of claim 2, wherein the DC-DC converter includes an energy storage controller and additional converter circuit for transferring output power to and from an external storage module in response to power availability from the solar panels and demand from the high voltage output bus.