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

• US 7,269,036 B2
• Filed: 05/12/2004
• Issued: 09/11/2007
• Est. Priority Date: 05/12/2003
• Status: Active Grant

• Current Assignee: Rhombus Energy Solutions, Inc. (BorgWarner Incorporated)
• Original Assignee: Siemens VDO Automotive Corporation (Siemens AG)
• Inventors: Harmon, Kent M., Deng, Duo, Tuladhar, Anil
• Primary Examiner(s): Easthom; Karl
• Assistant Examiner(s): BEHM, HARRY RAYMOND
• Application Number:
  US10/844,060
• Publication Number:
  US 20050018454A1
• Time in Patent Office: 1,217 Days
• Field of Search: 323/906, 323/901, 363/49, 713/340
• 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 from a power source, the method comprising:

selecting between a value of a 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;

determining a voltage available from the power source;

determining if the determined voltage available from the power source exceeds the selected value of the wakeup voltage parameter;

if the determined voltage available from the power source exceeds a threshold corresponding to the selected value of the wakeup voltage parameter,

determining a power available from the power source;

determining if the power available from the power source is less than a startup power threshold;

providing power to a load if the power available from the power source is not less than the startup power threshold;

calculating a value of the wakeup voltage parameter based on the power available from the power source with respect to the startup power threshold; and

activating power electronics that are brought out of a sleep state.

2. The method of claim 1, further comprising:

enabling a maximum power point tracking algorithm in response to determining that the determined voltage available from the power source exceeds the selected value of the wakeup voltage parameter.

3. The method of claim 1, further comprising:

waiting a first defined period of time after enabling the maximum power point tracking algorithm to allow some transients, if any, to settle before determining the power available from the power source.

4. The method of claim 1, further comprising:

determining that the determined power available from the power source remains below the startup power threshold for a defined period of time before calculating the value of the wakeup voltage parameter.

5. The method of claim 1, further comprising:

entering a sleep operating state without providing power to a load if the determined voltage available from the power source does not exceed the selected value of the wakeup voltage parameter.

6. The method of claim 5, further comprising:

decoupling a transformer of the electrical power converter system from a grid when entering the sleep operating state of the electrical power converter system.

7. The method of claim 1 wherein selecting between a value of a 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, comprises:

determining a real time;

determining an operating state of the electrical power converter system;

selecting the wakeup voltage parameter stored in the historically based lookup table if both the operating state is a sleep state and the real time is at least equal to a wakeup time.

8. An electrical power converter system, comprising:

an input bus;

an output bus;

at least one switch electrically coupled between the input and the output buses; and

a controller coupled to control the at least one switch, the controller configured to select between a value of a 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, and configured to determine an amount of power available from a power source at approximately a startup time,

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.

9. The electrical power converter system of claim 8 wherein the controller is configured to select the value of the wakeup voltage parameter stored in the historically based lookup table if both an operating state of the electrical power converter system is a sleep state and a real time is at least equal to a wakeup time.

10. The electrical power converter system of claim 9 wherein the controller is configured to determine if a voltage available from the power source exceeds the selected value of the wakeup voltage parameter;

if the determined voltage available from the power source exceeds the selected value of the wakeup voltage parameter, provide power to a load if a power available from the power source is not less than a startup power threshold; and

calculate a value of the wakeup voltage parameter based on the power available from the power source relative to the startup power threshold.

11. The electrical power converter system of claim 9 wherein the controller is configured to execute a maximum power point tracking algorithm in response to determining that a voltage available from the power source exceeds the selected value of the wakeup voltage parameter.

12. The electrical power converter system of claim 11 wherein the controller is configured to place the electrical power converter system into a sleep operating state without providing power to a load if the voltage available from the power source does not exceed the selected value of the wakeup voltage parameter.