Device For Distributed Maximum Power Tracking For Solar Arrays

• US 20080303503A1
• Filed: 07/12/2005
• Published: 12/11/2008
• Est. Priority Date: 07/13/2004
• Status: Active Grant

• Current Assignee: Tigo Energy, Inc
• Original Assignee: Central Queensland University, Queensland State Department of Public Works
• Inventors: Wolfs, Peter
• Granted Patent: US 7,839,022 B2
• Time in Patent Office: Days
• US Class Current: 323/301
• CPC Class Codes: G05F 1/67 to the maximum power available from a generator, e.g. from solar cell
• CPC Class Codes: G05F 5/00 Systems for regulating electric variables by detecting deviations in the electric input to the system and thereby controlling a device within the system to obtain a regulated output
• 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: H02M 1/0077 Plural converter units whose outputs are connected in series
• CPC Class Codes: H02M 3/158 including plural semiconductor devices as final control devices for a single load
• CPC Class Codes: Y02E 10/56 Power conversion systems, e.g. maximum power point trackers
• CPC Class Codes: Y10S 323/906 Solar cell systems

Abstract

The present invention is a system for providing power from solar cells whereby each cell or cell array is allowed to produce its maximum available power and converted by an operatively connected DC/DC converter. Each cell or cell array has its own DC/DC converter. In one form the system for providing power from solar cells includes one or more solar generators wherein each of said solar generators has one to nine solar cells; a maximum power tracker operatively associated with each solar generator, each of said maximum power tracker includes a buck type DC/DC converter without an output inductor, each of said maximum power trackers are operatively connected in series with each other; an inductor operatively connected to the series connected maximum power trackers; and means for providing electrical power from the inductor to load means, wherein each of said maximum power trackers is controlled so that the operatively associated solar generator operates at its maximum power point to extract maximum available power.

Claims

1. A system for providing power from solar cells including

one or more solar generators wherein each of said solar generators has one to nine solar cells;

a maximum power tracker operatively associated with each solar generator, each of said maximum power tracker includes a buck type DC/DC converter without an output inductor, each of said maximum power trackers are operatively connected in series with each other;

an inductor operatively connected to the series connected maximum power trackers; and

means for providing electrical power from the inductor to a load, wherein each of said maximum power trackers is controlled so that the operatively associated solar generator operates at its maximum power point to extract maximum available power.

2. A system as claimed in claim 1 wherein the maximum power tracker includes an energy storage capacitor and a control means for adjusting the buck type DC/DC converter duty cycle so that a connected solar generator operates at its maximum power point.

3. A system as claimed in claim 1 wherein the maximum power tracker includes an energy storage capacitor and a control means for adjusting the buck type DC/DC converter duty cycle so that a connected solar generator operates at its maximum power point;

said control means makes observations of solar generator voltage, and observations of the change in energy storage capacitor voltage during the buck converter switch off time and observations of the duration of the buck converter switch off time to infer solar generator power to adjust the buck converter duty cycle to extract maximum power from the connected solar generator.

4. A system as claimed in claim 1, wherein the switching operations of the DC/DC converter are synchronized in frequency by the use of a synchronizing signal.

5. A system as claimed in claim 1, wherein each solar generator includes at least one solar cell.

6. A system as claimed in claim 1, wherein each solar generator includes at least one solar cell and each solar cell is connected to its own dedicated maximum power tracker so that the tracker responds to its connected solar cell.

7. A system as claimed in claim 1, wherein the system uses a single inductor.

8. A system as claimed in claim 1, wherein the load includes devices that use or store the electrical power.

9. (canceled)