Modular System For Unattended Energy Generation And Storage

• US 20110199044A1
• Filed: 04/23/2011
• Published: 08/18/2011
• Est. Priority Date: 12/22/2006
• Status: Active Grant

• Current Assignee: Enphase Energy Incorporated
• Original Assignee: Solarbridge Technologies Incorporated (Totalenergies Se)
• Inventors: Kimball, Jonathan W., Krein, Philip T., Benavides, Nicholas D.
• Granted Patent: US 8,350,411 B2
• Time in Patent Office: Days
• US Class Current: 320/101
• CPC Class Codes: H02J 7/34 Parallel operation in networks using both storage and other dc sources, e.g. providing buffering H02J7/14 takes precedence
• CPC Class Codes: H02J 7/345 using capacitors as storage or buffering devices
• CPC Class Codes: H02J 7/35 with light sensitive cells

Abstract

An apparatus and method for supplying energy to a load includes an energy recharge unit, an energy storage unit, an energy converter connected to the energy recharge unit, the energy converter being capable of transferring energy at a power level from the energy recharge unit to an output node, the power level being determined by a power transfer controller, and a bi-directional energy converter connected to the energy storage unit and to the output node. The bi-directional energy converter is capable of converting energy of varying voltages from the energy storage unit to energy of varying current levels to supplement the transferred energy with energy from the energy storage unit so as to maintain a constant voltage on the output node. The bi-directional energy converter is capable of converting the transferred energy to provide charging energy to the energy storage unit when the transferred energy exceeds a demand level of the load while maintaining the constant voltage at the output node.

Claims

1. An electrical power supply comprising:

an electrical load;

a solar panel;

an energy storage capacitor electrically coupled to the solar panel;

a power conversion system having an input electrically coupled to the solar panel and an output electrically coupled to the electrical load, wherein the power conversion system is configured to supply power to the electrical load in short-term bursts; and

a controller configured to control the power conversion system according to a maximum power point tracking (MPPT) method to substantially maximize the power drawn from the solar panel and exchange power with the energy storage capacitor to maintain the voltage of the energy storage capacitor above a predetermined threshold.

2. The electrical power supply of claim 1, wherein the controller comprises a controller configured to achieve a predetermined minimum energy conversion efficiency level of the power conversion system by exchanging power with the energy storage capacitor to maintain the voltage of the energy storage capacitor above the predetermined threshold.

3. The electrical power supply of claim 1, wherein the controller is configured to control the power conversion system according to a ripple correlation MPPT method.

4. The electrical power supply of claim 1, wherein the controller is configured to control the power conversion system according to a perturb-and-observe MPPT method.

5. The electrical power supply of claim 1, wherein the controller is configured to control the power conversion system according to a constant-voltage-fraction MPPT method.

6. The electrical power supply of claim 1, wherein the power conversion system is configured to supply power to the electrical load in short-term bursts in response to a weather condition that causes the solar panel to produce less power.

7. The electrical power supply of claim 1, wherein the power conversion system comprises a first direct current-to-direct current (DC-DC) converter electrically connected to the energy storage capacitor and the output of the power conversion system.

8. The electrical power supply of claim 1, wherein the power conversion system comprises a second DC-DC electrically connected to the input of the power conversion system and to the output of the power conversion system.

9. An electrical power supply comprising:

an electrical load;

a solar panel to generate an input power;

an energy storage capacitor electrically coupled to the solar panel;

a power conversion system having an input electrically coupled to the solar panel and an output electrically coupled to the electrical load; and

a controller configured to (i) control the power conversion system according to a maximum power point tracking (MPPT) method to substantially maximize the power drawn from the solar panel, (ii) control the power conversion system to store energy in the energy storage capacitor during a first time period, and (iii) control the power conversion system to supply energy from the energy storage capacitor to the electrical load during a second time period during which the input power of the solar panel is less than a required power of the load.

10. The electrical power supply of claim 9, wherein the first time period occurs while a charge level of the energy storage capacitor is less than a minimum threshold and the second time period occurs while the charge level of the energy storage capacitor is greater than the minimum threshold.

11. The electrical power supply of claim 9, wherein the controller is further configured to exchange power with the energy storage capacitor to maintain the voltage of the energy storage capacitor above a predetermined threshold.

12. The electrical power supply of claim 11, wherein the controller comprises a controller configured to achieve a predetermined minimum energy conversion efficiency level of the power conversion system by exchanging power with the energy storage capacitor to maintain the voltage of the energy storage capacitor above the predetermined threshold.

13. The electrical power supply of claim 9, wherein the controller is configured to control the power conversion system according to a ripple correlation MPPT method.

14. The electrical power supply of claim 9, wherein the controller is configured to control the power conversion system according to a perturb-and-observe MPPT method.

15. The electrical power supply of claim 9, wherein the controller is configured to control the power conversion system according to a constant-voltage-fraction MPPT method.

16. The electrical power supply of claim 9, wherein the controller is configured to the power conversion system to store energy in the energy storage capacitor during the first time period in response to a weather condition that causes the solar panel to produce less power.

17. The electrical power supply of claim 9, wherein the power conversion system comprises a first direct current-to-direct current (DC-DC) converter electrically connected to the energy storage capacitor and the output of the power conversion system.

18. The electrical power supply of claim 9, wherein the power conversion system comprises a second DC-DC electrically connected to the input of the power conversion system and to the output of the power conversion system.

20. The method of claim 18, wherein:

causing energy generated by the solar panel to be stored in the energy storage capacitor comprises causing energy generated by the solar panel to be stored in the energy storage capacitor of the electrical power supply while a charge level of the energy storage capacitor is less than a minimum threshold, and

causing energy to be supplied from the energy storage capacitor to the electrical load comprises causing energy to be supplied from the energy storage capacitor to the electrical load during while the charge level of the energy storage capacitor is greater than the minimum threshold.

19. A method for controlling an electrical power supply electrically coupled to a electrical load, the method comprising:

controlling a power conversion system of the electrical power supply to draw power from a solar panel according to a power point tracking method to substantially maximize the power drawn from the solar panel;

causing energy generated by the solar panel to be stored in an energy storage capacitor of the electrical power supply during a first time period; and

causing energy to be supplied from the energy storage capacitor to the electrical load during a second time period during which the power generated by the solar panel is less than a required power of the electrical load.