Method and apparatus for adjusting wakeup time in electrical power converter systems and transformer isolation

• US 7,466,571 B2
• Filed: 07/02/2007
• Issued: 12/16/2008
• Est. Priority Date: 05/12/2003
• Status: Expired due to Fees

• Current Assignee: Continental Automotive Systems US Incorporated (Continental AG)
• Original Assignee: Continental Automotive Systems US Incorporated (Continental AG)
• Inventors: Harmon, Kent M., Deng, Duo, Tuladhar, Anil
• Primary Examiner(s): Sterrett; Jeffrey L.
• Assistant Examiner(s): BEHM, HARRY RAYMOND
• Application Number:
  US11/772,428
• Publication Number:
  US 20080013347A1
• Time in Patent Office: 533 Days
• Field of Search: 323/906, 323/901, 323/221, 363/49, 713/340, 320/101, 307/126, 702/60, 700/286
• US Class Current: 363/49
• CPC Class Codes: H02J 2300/20 The dispersed energy generation being of renewable origin
• CPC Class Codes: H02J 2300/24 of photovoltaic origin
• 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 2300/30 The power source being a fuel cell
• CPC Class Codes: H02J 3/381 Dispersed generators
• CPC Class Codes: H02J 3/466 Scheduling the operation of the generators, e.g. connecting or disconnecting generators to meet a given demand
• CPC Class Codes: H02J 7/35 with light sensitive cells
• CPC Class Codes: Y02B 10/10 Photovoltaic [PV]
• CPC Class Codes: Y02E 10/56 Power conversion systems, e.g. maximum power point trackers
• CPC Class Codes: Y10S 323/901 Starting circuits
• CPC Class Codes: Y10S 323/906 Solar cell systems

Abstract

An electrical power converter system adjusts a wakeup voltage periodically, to permit earlier connection and/or operation, to increase performance. The electrical power converter system selects between a mathematically adjusted wakeup voltage based on at least one previous period, and a table derived wakeup voltage that takes into account historical information. The electrical power converter system is particularly suited to applications with periodicity such as solar based photovoltaic power generation.

Claims

1. A method of operating an electrical power converter system to transform power for a power source, the method comprising:

determining an amount of power available from a power source at approximately a startup time;

adjusting a value of a wakeup voltage parameter of the electrical power converter system from a value of the wakeup voltage parameter of the electrical power converter system for a previous period based at least in part on the determined amount of power available from the power source at approximately the startup time by increasing the value of the wakeup voltage parameter if the amount of power available from the power source at approximately the startup time is less than a startup power threshold; and

in response to the determined amount of power from the power source surpassing a threshold corresponding to the wakeup voltage parameter, activating power electronics that are brought out of a sleep state.

2. The method of claim 1 wherein adjusting the value of a wakeup voltage parameter of the electrical power converter system from the value of the wakeup voltage parameter of the electrical power converter system from the previous period based at least in part on the determined amount of power available from the power source at approximately the startup time comprises calculating the value of the wakeup voltage parameter in real time based on the amount of power available from the power source at approximately the startup time relative to a startup power threshold, and further comprising:

selecting between the value of the wakeup voltage parameter calculated in real time and a value of the wakeup voltage parameter stored in a historically based lookup table, wherein the value of the wakeup voltage parameter from the historically based lookup table is based at least in part on a real time clock.

3. The method of claim 1, further comprising:

determining that the determined amount of power available from the power source at approximately the startup time remains below a startup power threshold for a defined period of time before adjusting the value of a wakeup voltage parameter of the electrical power converter system.

4. The method of claim 1, further comprising:

electrically coupling a transformer of the electrical power converter system to a power grid when a voltage available from the power source exceeds the value of the wakeup voltage parameter.

5. The method of claim 1, further comprising:

operating a main inverter of the electrical power converter system to supply AC power to a power grid when a voltage available from the power source exceeds the value of the wakeup voltage parameter.

6. The method of claim 1 wherein the previous period is one day.

7. The method of claim 1 wherein the previous period is a day immediately previous to a current day.

8. The method of claim 1 wherein the previous period is greater than one day.

9. The method of claim 1, further comprising:

receiving a start command; and

enabling a maximum power point tracking algorithm after receiving the start command, wherein the startup time occurs a first defined period of time after enabling the maximum power point tracking algorithm, allowing some transients, if any, to settle.

10. A method of operating an electrical power converter system to transform power for a power source, the method comprising:

determining an amount of power available from a power source at approximately a startup time;

adjusting a value of a wakeup voltage parameter of the electrical power converter system from a value of the wakeup voltage parameter of the electrical power converter system for a previous period based at least in part on the determined amount of power available from the power source at approximately the startup time by decreasing the value of the wakeup voltage parameter if the amount of power available from the power source at approximately the startup time is greater than a startup power threshold; and

in response to the determined amount of power from the power source surpassing a threshold corresponding to the wakeup voltage parameter, activating power electronics that are brought out of a sleep state.

11. An electrical power converter system, comprising:

at least a first switch operable between an ON state and an OFF state; and

a controller coupled to control the at least first switch, and configured to determine an amount of power available from a power source at approximately a startup time; and

adjust a value of a wakeup voltage parameter of the electrical power converter system from a value of the wakeup voltage parameter of the electrical power converter system for a previous period based at least in part on the determined amount of power available from the power source at approximately the startup time by increasing the value of the wakeup voltage parameter if the amount of power available from the power source at approximately the startup time is less than a startup power threshold such that in response to the determined amount of power from the power source surpassing a threshold corresponding to the wakeup voltage parameter, power electronics are brought out of a sleep state and activated.

12. The electrical power converter system of claim 11 wherein the controller is configured to select between a value of the wakeup voltage parameter calculated in real time and a value of the wakeup voltage parameter stored in a historically based lookup table, wherein the value of the wakeup voltage parameter from the historically based lookup table is based at least in part on a real world time.

13. The electrical power converter system of claim 11, further comprising:

a transformer, the controller configured to electrically couple the transformer of the electrical power converter system to a power grid when a voltage available from the power source exceeds the value of the wakeup voltage parameter.

14. The method of claim 11, further comprising:

a main inverter, the controller configured to operate the main inverter of the electrical power converter system to supply AC power to a power grid when a voltage available from the power source exceeds the value of the wakeup voltage parameter.

15. An electrical power converter system. comprising:

at least a first switch operable between an ON state and an OFF state; and

a controller coupled to control the at least first switch, and configured to determine an amount of power available from a power source at approximately a startup time; and

adjust the value of the wakeup voltage parameter of the electrical power converter system from the value of the wakeup voltage parameter from the previous period based at least in part on the determined amount of power available from the power source at approximately the startup time by decreasing the value of the wakeup voltage parameter if the amount of power available from the power source at approximately the startup time is greater than a startup power threshold such that in response to the determined amount of power from the power source surpassing a threshold corresponding to the wakeup voltage, power electronics are brought out of a sleep state and activated.