Optimum power tracking for distributed power sources

• US 9,325,176 B2
• Filed: 05/02/2012
• Issued: 04/26/2016
• Est. Priority Date: 05/02/2012
• Status: Active Grant

• Current Assignee: Aerospace Corporation
• Original Assignee: Aerospace Corporation
• Inventors: Siri, Kasemsan
• Primary Examiner(s): Kaplan, Hal
• Assistant Examiner(s): Ortiz, Elim
• Application Number:
  US13/462,112
• Publication Number:
  US 20130293022A1
• Time in Patent Office: 1,455 Days
• Field of Search: 307/46
• US Class Current: 1/1
• 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 3/46 Controlling of the sharing of output between the generators, converters, or transformers
• CPC Class Codes: Y02E 10/56 Power conversion systems, e.g. maximum power point trackers

Abstract

Embodiments of the present invention provide an apparatus for optimum power tracking for distributed power sources. The apparatus includes a plurality of distributed-input parallel-output converters. Each converter is operably connected to a corresponding power source to form a power-processing channel. The apparatus also includes a controller operably connected to the plurality of converters, and is configured to provide uniform input voltages across each power source while tracking an optimum power point. The controller provides tolerance for multiple faults up to N−1 power source failures for the apparatus comprising an N-channel converter power system with N distributed power sources.

Claims

1. An apparatus, comprising:

a plurality of distributed-input parallel-output converters, each of the plurality of distributed-input parallel-output converters operably connected to a corresponding power source; and

a controller external to each of the plurality of distributed-input parallel-output converters and connected to each of the plurality of distributed-input parallel-output converters, wherein

the controller is further configured to receive a plurality of feedback input signals from each corresponding power source, and transmit a voltage control signal to each of the plurality of distributed-input parallel-output converters when one of the corresponding power sources experiences a reduction in power, such that uniform input voltages across each power source is achieved while tracking an optimum power point of each power source.

2. The apparatus of claim 1, wherein the controller comprises:

a battery charge controller configured to regulate a battery bus voltage signal to a preset value based on a voltage-temperature profile to prevent overcharging of a battery.

3. The apparatus of claim 1, wherein the controller further comprises:

a maximum power tracking controller configured to generate a commanding set point reference voltage signal, wherein the commanding set point reference voltage signal comprises a set point reference voltage signal and an AC dither voltage signal.

4. The apparatus of claim 3, wherein the maximum power tracking controller is further configured to process a total system bus current signal and an AC dither voltage signal to generate the commanding set point voltage signal, wherein the total system bus current is a total output current delivered from the plurality of distributed-input parallel-output converters.

5. The apparatus of claim 1, wherein the controller further comprises an input voltage regulator configured to generate a system control voltage signal based on a commanding set point voltage signal and a maximum limit voltage signal, wherein the maximum limit voltage signal corresponds to a highest voltage among input voltages from each respective power source.

6. The apparatus of claim 1, wherein the controller further comprises a uniform voltage distribution controller configured to generate a distributed control voltage for each distributed-input parallel-output converter such that optimum power is maintained across each power source.

7. The apparatus of claim 6, wherein the uniform voltage distribution controller comprises:

an input voltage distribution controller configured to generate a secondary voltage control signal for each distributed-input parallel-output converter based on a common distributed voltage reference signal and input voltages obtained from each of the plurality of distributed-input parallel-output converters.

8. The apparatus of claim 6, wherein the uniform voltage distribution controller comprises:

a fault tolerant input voltage distribution controller configured to generate a secondary voltage control signal for each distributed-input parallel-output converter based on a highest voltage, wherein the highest voltage is determined based on an input voltage from each of the plurality of distributed-input parallel-output converters.

9. The apparatus of claim 1, wherein the controller is further configured to receive a plurality of feedback input signals from each corresponding power source, and transmit the voltage control signal to one of the plurality of distributed-input parallel-output converters, which is connected to the corresponding power source experiencing a reduction in power.

10. The apparatus of claim 9, wherein the reduction of power comprises when one or more of the corresponding power sources loses input power, or when an operation mode other than a maximum power tracking mode controls the plurality of distributed-input parallel-output converters.

11. An apparatus, comprising:

a system controller external to each of a plurality of distributed-input parallel-output converters, and configured to receive a plurality of feedback input signals from each corresponding power source, and transmit a voltage control signal to each of the plurality of distributed-input parallel-output converters when one of the corresponding power sources experiences a reduction in power such that uniform input voltages across each power source is achieved while tracking an optimum power point of each power source.

12. The apparatus of claim 11, wherein each of the distributed-input parallel-output converters is operably connected to a corresponding power source.

13. The apparatus of claim 11, wherein the system controller is further configured to apply the voltage control signal to regulate input voltages across each of the plurality of distributed-input parallel-output converters during a reduction in power by at least one of the power sources.

14. The apparatus of claim 11, wherein the system controller comprises a maximum power tracking controller configured to receive a signal feedback signal to search for peak power voltage.

15. The apparatus of claim 14, wherein the maximum power tracking controller is further configured to generate a commanding set point reference voltage signal comprising a set point reference voltage signal and an AC dither voltage signal to regulate a common distribution voltage reference signal.

16. The apparatus of claim 11, wherein the system controller comprises an input voltage regulator configured to generate a system control voltage signal based on a commanding set point reference voltage signal and a common distribution voltage reference signal, and the common distribution voltage reference signal is a maximum voltage detected from input voltages across each of the plurality of power sources.

17. The apparatus of claim 11, wherein the system controller comprises a uniform voltage distribution controller configured to generate distributed control voltages for each distributed-input parallel-output converter such that optimum power is maintained across each power source.

18. A system controller, comprising:

a uniform voltage distribution controller external to each of a plurality of distributed-input parallel-output converters, and configured to process a system control voltage and generate distributed control voltages that are applied across each of the plurality of distributed-input parallel-output converters such that uniform input voltage is achieved across each of a plurality of respective power sources, wherein

the uniform voltage distribution controller is and is further configured to receive a plurality of feedback input signals from each corresponding power source and transmit a voltage control signal to each of the plurality of distributed-input parallel-output converters when one of the corresponding power sources experiences a reduction in power, such that uniform input voltages across each power source is achieved while tracking an optimum power point of each power source.

19. The system controller of claim 18, further comprising:

a battery charge controller configured to regulate a battery bus voltage signal to a preset value based on a voltage-temperature profile to prevent overcharging of a battery.

20. The system controller of claim 18, further comprising:

a maximum power tracking controller configured to generate a commanding set point reference voltage signal to regulate a common distribution voltage reference signal, wherein the commanding set point reference voltage signal comprises a set point reference voltage signal and an AC dither voltage signal, wherein the common distribution voltage reference signal corresponds to a highest voltage among input voltages obtained from each respective power source.

21. The system controller of claim 18, further comprising:

an input voltage regulator configured to generate a system control voltage signal based on a commanding set point reference voltage signal and a common distribution voltage reference signal.

22. The system controller of claim 18, wherein the uniform voltage distribution controller is further configured to subtract secondary voltage control signals from a system control voltage signal to generate the distributed control voltages for each distributed-input parallel-output converter.