Photovoltaic Power Output-Utilizing Device

• US 20080224652A1
• Filed: 07/20/2005
• Published: 09/18/2008
• Est. Priority Date: 07/20/2005
• Status: Active Grant

• Current Assignee: Ecosol Technologies, Inc.
• Original Assignee: Ecosol Solar Technologies Inc.
• Inventors: Kular, Andrew C., Zhu, Zuohang
• Granted Patent: US 8,264,193 B2
• Time in Patent Office: Days
• US Class Current: 320/101
• CPC Class Codes: H02J 7/345 using capacitors as storage or buffering devices
• CPC Class Codes: H02J 7/35 with light sensitive cells
• CPC Class Codes: H02S 40/38 Energy storage means, e.g. batteries, structurally associated with PV modules
• CPC Class Codes: Y02E 10/56 Power conversion systems, e.g. maximum power point trackers
• CPC Class Codes: Y02E 70/30 Systems combining energy storage with energy generation of non-fossil origin

Abstract

Briefly described, the invention provides a photovoltaic assembly power output utilizing device which partially charges a capacitor assembly. This capacitor assembly is then partially discharged by a DC/DC power converter in different ranges of voltages in which the power output from the photovoltaic assembly peaks for different light intensities.

Claims

1. A photovoltaic assembly power output utilizing device, comprising:

a photovoltaic assembly having a power output, said power output having at least one peak power output value;

a capacitor assembly, having an adjustable input voltage and capable of being partially dischargeable; and

,

an electronic control circuit for charging the capacitor assembly by the photovoltaic assembly and then partially discharging the capacitor assembly, said charging occurring in a photovoltaic assembly output voltage range wherein said at least one peak power output value occurs.

2. The device according to claim 1 wherein said discharging occurs in a photovoltaic assembly output voltage range wherein said at least one peak power output value occurs.

3. The device according to claim 2, wherein said output voltage range is one of a plurality of voltage ranges and the electronic control circuit comprises:

a means for monitoring, as a function of time, the current and voltage outputs from the photovoltaic assembly; and

,

a means for changing the voltage range in which the capacitor assembly is charged and partially discharged to thereby obtain power from the photovoltaic assembly at or near its peak value.

4. The device according to claim 3, wherein the electronic control circuit determines a maximum power output has occurred and initiates said discharge of the capacitor assembly when the power output subsequently drops to a threshold percentage of said maximum power output.

5. The device according to claim 4, wherein the electronic control circuit stops discharging of the capacitor assembly when the power output subsequently drops to a threshold percentage of said maximum power output.

6. A device according to claim 1, wherein the capacitor assembly is a super-capacitor assembly.

7. A device according to claim 1, further comprising a capacitor assembly output DC/DC converter.

8. A device according to claim 7, wherein the DC/DC converter is for converting at least some of the capacitor assembly discharge voltages to a desired voltage level.

9. A device according to claim 7, wherein the DC/DC converter is for converting at least some of the capacitor assembly discharge currents to a desired current level.

10. A device according to claim 3, wherein the control circuit contains a programmed electronic control circuit.

11. A device according to claim 3, wherein the electronic circuit contains firmware composed of instructional sets and algorithms.

12. A device according to claim 3, wherein the electronic circuit contains a field programmable gate array.

13. A device according to claim 3, wherein the electronic circuit contains a microcontroller.

14. A device according to claim 3, wherein the electronic circuit contains an application-specific integrated circuit.

15. A device according to claim 7, wherein the DC/DC converter is a switching-mode DC/DC converter.

16. A device according to claim 7, wherein the DC/DC converter is a one-way ON/OFF direct charging switch.

17. A device according to claim 7, wherein the DC/DC converter is a step-up (boost) DC/DC converter.

18. A device according to claim 7, wherein the DC/DC converter is a step-down (buck) DC/DC converter.

19. A device according to claim 7, wherein the DC/DC converter is a buck-boost DC/DC converter.

20. A device according to claim 7, wherein the device is for charging electrical energy storage device, the DC/DC converter is for increasing the capacitor assembly output discharge voltage to a storage device charging voltage, and the device further comprises a direct discharge path to the energy storage device, and means for

i) Charging the energy storage device through the DC/DC converter when the capacitor assembly discharge voltage needs to be increased, and

ii) Charging the energy storage device directly by the direct discharge path when the capacitor assembly discharge voltage is at least the said charge voltage.

21. A method for using power output from a photovoltaic assembly device having a capacitor assembly, said method comprising:

monitoring, as a function of time, the voltage output from the photovoltaic assembly to determine when a peak value has occurred;

charging the capacitor assembly by the photovoltaic assembly and then partially discharging the capacitor assembly, said charging occurring in a photovoltaic assembly output voltage range wherein said at least one peak power output value occurs.

22. The method according to claim 21 wherein said discharging occurs in a photovoltaic assembly output voltage range wherein said at least one peak power output value occurs.

23. The method according to claim 22, wherein said output voltage range is one of a plurality of voltage ranges and the method further comprises:

changing the voltage range in which the capacitor assembly is charged and partially discharged to thereby obtain power from the photovoltaic assembly at or near its peak value.

24. The method according to claim 23 further comprising:

determining when a maximum power output has occurred and

initiating said discharge of the capacitor assembly when the power output subsequently drops to a threshold percentage of said maximum power output.

25. The method according to claim 24 further comprising:

stopping said discharging of the capacitor assembly when the power output subsequently drops to a threshold percentage of said maximum power output.

26. The method according to claim 24 wherein said determining step comprises:

measuring a change in voltage in a period of time, Δ

T.

27. The method according to claim 26 further comprising:

changing Δ

T in response to a change in output current from the photovoltaic assembly device.