Method and system for activating and deactivating an energy generating system

• US 9,077,206 B2
• Filed: 05/14/2008
• Issued: 07/07/2015
• 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: Zhang, Jianhui, Djabbari, Ali, Lisi, Gianpaolo
• Primary Examiner(s): Johnson, Jonathan
• Assistant Examiner(s): BERNIER, LINDSEY A
• Application Number:
  US12/152,478
• Publication Number:
  US 20090283128A1
• Time in Patent Office: 2,610 Days
• Field of Search: 136/244, 136/252, 136/293
• US Class Current: 1/1
• 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 system for activating and deactivating at least one of a plurality of local converters for a specified one of a plurality of energy generating devices in an energy generating array, the system comprising:

a corresponding local controller configured to perform maximum power point tracking for its own corresponding specified energy generating device of the plurality of energy generating devices and to turn on and off a power stage of the corresponding local converter for the corresponding energy generating device; and

an activator coupled to the corresponding local controller, the activator configured to automatically activate and deactivate the corresponding local controller responsive to a device voltage measured from the specified corresponding energy generating device;

wherein the activator comprises a power supply configured to generate a supply voltage and to provide the supply voltage to the corresponding local controller, wherein;

the power supply comprises a shutdown node; and

the power supply is configured to generate a non-zero supply voltage when a voltage level at the shutdown node is greater than a specified voltage and to generate a zero supply voltage when the voltage level at the shutdown node is less than the specified voltage, the power supply further comprises an input node and an output node;

the activator further comprises a first resistor, a second resistor, a third resistor and a diode;

the first and second resistors are coupled in series between the input node and a ground;

the third resistor and the diode are coupled in series between the output node and a node at which the first and second resistors are coupled together; and

the shutdown node is coupled to the node at which the first and second resistors are coupled together.

2. The system of claim 1, wherein the activator is configured to automatically activate the local controller by generating a non-zero supply voltage with the power supply when the device voltage from the specified energy generating device exceeds a voltage activation level.

3. The system of claim 2, wherein the activator is configured to automatically deactivate the local controller by generating a zero supply voltage with the power supply when a device current from the specified energy generating device drops below an activation current level.

4. The system of claim 1, wherein the plurality of energy generating devices comprise photovoltaic panels.

9. The system of claim 1, wherein:

the local controller is configured when activated to perform one or more activation procedures for the local converter, the one or more activation procedures comprising at least one of;

initialization of a register, a preliminary voltage comparison between multiple energy generating devices, an analog-to-digital converter calibration, clock synchronization or interleaving, and synchronous activation of a string of respective energy generating devices; and

the local controller is configured when deactivated to perform one or more deactivation procedures for the local converter, the one or more deactivation procedures comprising at least one of;

synchronization with a back-up unit and synchronous deactivation of the power stage.

5. A plurality of local converters for a plurality of energy generating devices in an energy generating array, each of the plurality of local converters comprising:

a power stage configured to reshape a voltage-to-current relationship of a device voltage and a device current from one of the plurality of energy generating devices;

a corresponding local controller configured to perform maximum power point tracking for its own corresponding energy generating device of the plurality of energy generating devices and to turn on and off the power stage for the corresponding local converter for the corresponding energy generating device; and

an activator configured to automatically activate and deactivate the corresponding local controllers responsive to the device voltage from the corresponding energy generating device;

wherein the activator comprises a power supply configured to generate a supply voltage and to provide the supply voltage to the corresponding local controller,

the power supply comprises a shutdown node; and

the power supply is configured to generate a non-zero supply voltage when a voltage level at the shutdown node is greater than a specified voltage and to generate a zero supply voltage when the voltage level at the shutdown node is less than the specified voltage, wherein;

the power supply further comprises an input node and an output node;

the activator further comprises a first resistor, a second resistor, a third resistor and a diode;

the first and second resistors are coupled in series between the input node and a ground;

the third resistor and the diode are coupled in series between the output node and a node at which the first and second resistors are coupled together; and

the shutdown node is coupled to the node at which the first and second resistors are coupled together.

6. The plurality of local converters of claim 5, wherein each activator is configured to automatically activate each local controller by generating a non-zero supply voltage with the power supply when the device voltage from the respective energy generating device exceeds a voltage activation level.

7. The plurality of local converters of claim 5, wherein each activator is configured to automatically deactivate each local controller by generating a zero supply voltage with the power supply when the device current from the respective energy generating device drops below an activation current level.

8. The plurality of local converters of claim 5, wherein the respective energy generating device comprises a photovoltaic panel.

10. The plurality of local converters of claim 5, wherein each power stage is configured to operate with a specified conversion ratio when a device current from the respective energy generating device is below an activation current level.

11. The plurality of local converters of claim 10, wherein each local controller is configured to perform the maximum power point tracking for the respective energy generating device only when the device current from the energy generating device is above the activation current level.