Method and system for activating and deactivating an energy generating system

• US 20090283128A1
• Filed: 05/14/2008
• Published: 11/19/2009
• Est. Priority Date: 05/14/2008
• Status: Active Grant

• Current Assignee: National Semiconductor Corporation (Texas Instruments, Inc.)
• Original Assignee: National Semiconductor Corporation (Texas Instruments, Inc.)
• Inventors: Lisi, Gianpaolo, Djabbari, Ali, Zhang, Jianhui
• Granted Patent: US 9,077,206 B2
• Time in Patent Office: Days
• US Class Current: 136/244
• CPC Class Codes: H02J 2300/24 of photovoltaic origin
• 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: H02M 3/1582 Buck-boost converters H02M3/1584 takes precedence
• CPC Class Codes: Y02E 10/56 Power conversion systems, e.g. maximum power point trackers

Abstract

A method for activating a local converter for one of a plurality of energy generating devices in an energy generating array is provided. The local converter includes a power stage and a local controller. The method includes comparing a device voltage for the energy generating device to a voltage activation level. The local converter is automatically activated when the device voltage exceeds the voltage activation level.

Claims

1. A method for activating a local converter for one of a plurality of energy generating devices in an energy generating array, the local converter comprising a power stage and a local controller, the method comprising:

comparing a device voltage for the energy generating device to a voltage activation level; and

automatically activating the local converter when the device voltage exceeds the voltage activation level.

2. The method of claim 1, automatically activating the local converter comprising generating a non-zero supply voltage for the local controller.

3. The method of claim 1, automatically activating the local converter comprising setting at least one pin of the local controller.

4. The method of claim 1, automatically activating the local converter comprising writing a predefined value to a register in the local controller.

5. The method of claim 1, automatically activating the local converter comprising performing activation procedures for the local converter, the activation procedures comprising at least one of register initialization, clock synchronization, voltage comparisons for at least a subset of the energy generating devices in the array, and synchronous activation of at least a subset of the energy generating devices in the array.

6. The method of claim 1, the energy generating device included in a string of energy generating devices, automatically activating the local converter comprising operating the power stage with a predetermined conversion ratio until a power stage is operational in each energy generating device in the string.

7. The method of claim 1, automatically activating the local converter comprising:

comparing a device current for the energy generating device to an activation current level; and

when the device current exceeds the activation current level, performing maximum power point tracking for the energy generating device with the local controller.

8. The method of claim 7, further comprising automatically deactivating the local converter when the device current drops below the activation current level by monitoring the device current for a specified period of time and, when the device current remains below the activation current level for the specified period of time, completing deactivation of the local converter.

9. The method of claim 1, the energy generating devices comprising photovoltaic panels.

10. A method for deactivating a local converter for one of a plurality of energy generating devices in an energy generating array, the local converter comprising a power stage and a local controller, the method comprising:

comparing a device current for the energy generating device to an activation current level; and

automatically deactivating the local converter when the device current drops below the activation current level.

11. The method of claim 10, automatically deactivating the local converter comprising generating a zero supply voltage for the local controller.

12. The method of claim 10, automatically deactivating the local converter comprising setting at least one pin of the local controller.

13. The method of claim 10, automatically deactivating the local converter comprising writing a predefined value to a register in the local controller.

14. The method of claim 10, automatically deactivating the local converter comprising performing deactivation procedures for the local converter, the deactivation procedures comprising at least one of synchronization with a backup unit and synchronous deactivation of at least a subset of the energy generating devices in the array.

15. The method of claim 10, automatically deactivating the local converter comprising:

monitoring the device current for a specified period of time, and

when the device current remains below the activation current level for the specified period of time, completing deactivation of the local converter.

16. The method of claim 10, the energy generating devices comprising photovoltaic panels.

17. A system for activating and deactivating a local converter for one of a plurality of energy generating devices in an energy generating array, comprising:

a local controller capable of performing maximum power point tracking for the energy generating device and capable of turning on and off a power stage of the local converter; and

an activator coupled to the local controller, the activator capable of automatically activating and deactivating the local controller.

18. The system of claim 17, the activator comprising a power supply capable of generating a supply voltage for the local controller.

19. The system of claim 18, the activator capable of automatically activating the local controller by generating a non-zero supply voltage with the power supply when a device voltage for the energy generating device exceeds a voltage activation level.

20. The system of claim 19, the activator capable of automatically deactivating the local controller by generating a zero supply voltage with the power supply when a device current for the energy generating device drops below an activation current level.

21. The system of claim 18, the power supply comprising a shutdown node, the power supply capable of generating a non-zero supply voltage when a voltage level at the shutdown node is greater than a specified voltage and capable of generating a zero supply voltage when the voltage level at the shutdown node is less than or equal to the specified voltage.

22. The system of claim 21, the power supply further comprising an input node and an output node, the activator further comprising a first resistor, a second resistor, a third resistor and a diode, the first and second resistors coupled in series between the input node and a ground, the third resistor and the diode coupled in series between the output node and a node at which the first and second resistors are coupled together, and the shutdown node coupled to the node at which the first and second resistors are coupled together.

23. The system of claim 17, the energy generating devices comprising photovoltaic panels.