Method and Apparatus for Allocating Electricity from a Distributor

• US 20100066170A1
• Filed: 08/12/2009
• Published: 03/18/2010
• Est. Priority Date: 08/12/2008
• Status: Active Grant

• Current Assignee: Mike Schuler
• Original Assignee: Mike Schuler
• Inventors: Schuler, Mike
• Granted Patent: US 8,314,511 B2
• Time in Patent Office: Days
• US Class Current: 307/31
• CPC Class Codes: H02J 7/007 Regulation of charging or discharging current or voltage
• CPC Class Codes: H02J 7/04 Regulation of charging current or voltage
• CPC Class Codes: H02J 9/002 in which a reserve is maintained in an energy source by disconnecting non-critical loads, e.g. maintaining a reserve of charge in a vehicle battery for starting an engine
• CPC Class Codes: Y02B 70/30 Systems integrating technologies related to power network operation and communication or information technologies for improving the carbon footprint of the management of residential or tertiary loads, i.e. smart grids as climate change mitigation technology in the buildings sector, including also the last stages of power distribution and the control, monitoring or operating management systems at local level
• CPC Class Codes: Y04S 20/20 End-user application control systems

Abstract

The present invention provides a method and apparatus for allocating current (20) from a distributor (22), having a maximum rated current, among a plurality of load circuits (24), including a variable load circuit (24_α) that benefits from a full load current allocation but is operable at a lower current allocation. The invention provides for measuring the instantaneous current reserve of the distributor (22) as the maximum rated current of the distributor (22) less the instantaneous current flowing from the distributor (22) to the plurality of load circuits (24), and limiting the instantaneous current of the variable load circuit (24_α) to the full load current of the variable load circuit (24_α) if the instantaneous current reserve is greater than zero, and the sum of the full load current of the variable load circuit (24_α) plus the instantaneous current reserve, if the instantaneous current reserve is less than or equal to zero.

Claims

1. A method of allocating current from a distributor having a maximum rated current among a plurality of load circuits including a variable load circuit that benefits from a full load current allocation but is operable at a lower current allocation, comprising:

(a) measuring the instantaneous current reserve of the distributor as the maximum rated current of the distributor less the instantaneous current flowing from the distributor to the plurality of load circuits;

(b) limiting the instantaneous current of the variable load circuit to;

(i) the full load current of the variable load circuit, if the instantaneous current reserve is greater than zero; and

(ii) the sum of the full load current of the variable load circuit plus the instantaneous current reserve, if the instantaneous current reserve is less than or equal to zero.

2. A method as set forth in claim 1, wherein at least one aspect of measuring and limiting is performed in an analog manner.

3. A method as set forth in claim 1, wherein at least one of measuring and limiting includes:

(a) representing the respective currents as respective voltages; and

(b) at least one of

(i) comparing; and

(ii) summing

the respective voltages.

4. A method as set forth in claim 3, wherein:

(a) representing the maximum rated current of the distributor includes setting a reference voltage;

(b) representing the instantaneous current flowing from the distributor to the plurality of load circuits includes generating an instantaneous voltage signal in response to the instantaneous current; and

(c) measuring the instantaneous current reserve of the distributor includes summing the reference voltage and the instantaneous voltage signal.

5. A method as set forth in claim 4, wherein

(a) representing the full load current of the variable load circuit includes setting a second reference voltage;

and

(b) limiting the instantaneous current of the variable load circuit includes comparing the instantaneous current reserve to ground, and

(i) if the instantaneous current reserve is greater than ground, limiting the instantaneous current of the variable load circuit to the full load current of the variable load circuit, and

(ii) if the instantaneous current reserve is less than or equal to ground, limiting the instantaneous current of the variable load circuit to the sum of the full load current of the variable load circuit plus the instantaneous current reserve.

6. A method as set forth in claim 1, wherein at least one aspect of measuring and limiting is performed in a digital manner.

7. A method as set forth in claim 6, wherein at least one of measuring and limiting includes:

(a) representing the respective currents as binary values; and

(b) operating upon the binary values.

8. A method as set forth in claim 7, wherein:

(a) representing the maximum rated current of the distributor includes setting a memory register;

(b) representing the instantaneous current flowing from the distributor to the plurality of load circuits includes reading the output of an analog to digital converter coupled to a current sensor; and

(c) measuring the instantaneous current reserve of the distributor includes subtracting the instantaneous current flowing from the distributor from the maximum rated current of the distributor.

9. A method as set forth in claim 8, wherein

(a) representing the full load current of the variable load circuit includes setting a memory register;

and

(b) limiting the instantaneous current of the variable load circuit includes comparing the instantaneous current reserve to zero, and

(i) if the instantaneous current reserve is greater than zero, limiting the instantaneous current of the variable load circuit to the full load current of the variable load circuit, and

(ii) if the instantaneous current reserve is less than or equal to zero, limiting the instantaneous current of the variable load circuit to the sum of the full load current of the variable load circuit plus the instantaneous current reserve.

10. A method as set forth in claim 1, wherein limiting includes issuing a limit signal in response to the measured instantaneous current reserve circuit.

11. A method as set forth in claim 10, wherein limiting includes issuing the limit signal to a current limiter coupled to the variable load.

12. A method as set forth in claim 11, wherein limiting includes issuing the limit signal to a current limiter integrated with the variable load.

13. A method as set forth in claim 11, wherein issuing includes issuing wirelessly.

14. A method as set forth in claim 10, wherein limiting includes issuing the limit signal to a current limiter at the head of the variable load circuit.

15. A method as set forth in claim 10, wherein limiting includes issuing the limit signal to a current limiter integrated with the distributor at the head of the variable load circuit.

16. A method as set forth in claim 10, wherein the limit signal is pulse-width variable.

17. A method as set forth in claim 16, wherein the limit signal is pulse-width variable in accordance with the SAE J1772 standard.

18. A method as set forth in claim 1, wherein at least one of measuring and limiting is responsive to a user-input signal.

19. A method as set forth in claim 18, wherein the user-input signal is generated remote from the distributor.

20. A method as set forth in claim 1, wherein at least one of measuring and limiting is responsive to a safety signal.

21. A method as set forth in claim 10, wherein at least one of measuring and limiting is responsive to a safety signal that is fedback from the limit signal.

22. A method as set forth in claim 21, wherein the safety signal is a safety signal in accordance with the SAE J1772 standard.

23. A method as set forth in claim 10, wherein limiting the current of the variable load circuit includes limiting the respective currents of a plurality of variable load circuits.

24. A method as set forth in claim 23, wherein limiting the respective currents of a plurality of variable load circuits includes sharing the instantaneous current reserve.

25. A method as set forth in claim 24, wherein sharing the instantaneous current reserve includes sharing an instantaneous reserve current from the distributor.

26. A method as set forth in claim 25, wherein sharing an instantaneous reserve current includes multiplexing the instantaneous reserve current.

27. A method as set forth in claim 1, wherein the method of allocating current from a distributor is a method of allocating current from a distribution panel.

28. A method as set forth in claim 1, wherein the method of allocating current from a distributor is a method of allocating current from a distribution transformer.

29. A method as set forth in claim 1, wherein measuring the instantaneous current reserve of the distributor includes measuring the instantaneous current reserve of the distributor as the maximum rated current of the distributor less the instantaneous current flowing from the distributor in the phase corresponding to the phase of the variable load circuit.

30. A method as set forth in claim 1, wherein:

(a) the distributor is configured for at least one of split-phase and multi-phase supply;

(b) the variable load circuit is configured as a two-phase load; and

(c) measuring the instantaneous current reserve of the distributor includes measuring the instantaneous current reserve of the distributor as the maximum rated current of the distributor less the larger of the instantaneous current flowing from the distributor in each of the two phases supplying the variable load.

31. An apparatus for allocating current from a distributor having a maximum rated current among a plurality of load circuits including a variable load circuit that benefits from a full load current allocation but is operable at a lower current allocation, comprising:

(a) means for measuring the instantaneous current reserve of the distributor as the maximum rated current of the distributor less the instantaneous current flowing from the distributor to the plurality of load circuits;

(b) means for limiting the instantaneous current of the variable load circuit to;

(i) the full load current of the variable load circuit, if the instantaneous current reserve is greater than zero; and

(ii) the sum of the full load current of the variable load circuit plus the instantaneous current reserve, if the instantaneous current reserve is less than or equal to zero.

32. An apparatus as set forth in claim 31, wherein at least one of the means for measuring and the means for limiting functions in an analog manner.

33. An apparatus as set forth in claim 31, wherein at least one of the means for measuring and the means for limiting includes:

(a) respective means for representing the respective currents as respective voltages; and

(b) at least one of

(i) means for comparing; and

(ii) means for summing

the respective voltages.

34. An apparatus as set forth in claim 33, wherein:

(a) the means for representing the maximum rated current of the distributor includes means for generating a reference voltage;

(b) the means for representing the instantaneous current flowing from the distributor to the plurality of load circuits includes means for generating an instantaneous voltage signal in response to the instantaneous current; and

(c) the means for measuring the instantaneous current reserve of the distributor includes means for summing the reference voltage and the instantaneous voltage signal.

35. An apparatus as set forth in claim 34, wherein

(a) the means for representing the full load current of the variable load circuit includes means for generating a second reference voltage;

and

(b) the means for limiting the instantaneous current of the variable load circuit includes means for comparing the instantaneous current reserve to ground, and wherein in response,

(i) if the instantaneous current reserve is greater than ground, the means for limiting is operable to limit the instantaneous current of the variable load circuit to the full load current of the variable load circuit, and

(ii) if the instantaneous current reserve is less than or equal to ground, the means for limiting is operable to limit the instantaneous current of the variable load circuit to the sum of the full load current of the variable load circuit plus the instantaneous current reserve.

36. An apparatus as set forth in claim 31, wherein at least one of the means for measuring and the means for limiting functions in a digital manner.

37. An apparatus as set forth in claim 36, wherein at least one of the means for measuring and the means for limiting includes:

(a) means for representing the respective currents as binary values; and

(b) means for operating upon the binary values.

38. An apparatus as set forth in claim 37, wherein:

(a) the means for representing the maximum rated current of the distributor includes a memory register;

(b) the means for representing the instantaneous current flowing from the distributor to the plurality of load circuits includes an analog to digital converter coupled to a current sensor; and

(c) the means for measuring the instantaneous current reserve of the distributor includes means for subtracting the instantaneous current flowing from the distributor from the maximum rated current of the distributor.

39. An apparatus as set forth in claim 38, wherein

(a) the means for representing the full load current of the variable load circuit includes a second memory register;

and

(b) the means for limiting the instantaneous current of the variable load circuit includes means for comparing the instantaneous current reserve to zero, and wherein

(i) if the instantaneous current reserve is greater than zero, the means for limiting is operable to limit the instantaneous current of the variable load circuit to the full load current of the variable load circuit, and

(ii) if the instantaneous current reserve is less than or equal to zero, the means for limiting is operable to limit the instantaneous current of the variable load circuit to the sum of the full load current of the variable load circuit plus the instantaneous current reserve.

40. An apparatus as set forth in claim 31, wherein the means for limiting includes means for issuing a limit signal in response to the measured instantaneous current reserve circuit.

41. An apparatus as set forth in claim 40, wherein the means for limiting includes means for issuing the limit signal to a current limiter coupled to the variable load.

42. An apparatus as set forth in claim 41, wherein the means for limiting includes means for issuing the limit signal to a current limiter integrated with the variable load.

43. An apparatus as set forth in claim 41, wherein the means for issuing includes means for issuing the limit signal wirelessly.

44. An apparatus as set forth in claim 40, wherein the means for limiting includes means for issuing the limit signal to a current limiter at the head of the variable load circuit.

45. An apparatus as set forth in claim 40, wherein the means for limiting includes means for issuing the limit signal to a current limiter integrated with the distributor at the head of the variable load circuit.

46. An apparatus as set forth in claim 40, wherein the means for issuing the limit signal includes a pulse-width modulator.

47. An apparatus as set forth in claim 46, wherein the pulse-width modulator operates in accordance with the SAE J1772 standard.

48. An apparatus as set forth in claim 31, wherein at least one of the means for measuring and the means for limiting is responsive to a user-input signal.

49. An apparatus as set forth in claim 48, wherein the user-input signal is generated remote from the distributor.

50. An apparatus as set forth in claim 31, wherein at least one of the means for measuring and the means for limiting is responsive to a safety signal.

51. An apparatus as set forth in claim 40, wherein at least one of the means for measuring and the means for limiting is responsive to a safety signal that is fedback from the means for issuing.

52. An apparatus as set forth in claim 51, wherein the safety signal is a safety signal in accordance with the SAE J1772 standard.

53. An apparatus as set forth in claim 40, wherein the means for limiting the current of the variable load circuit includes means for limiting the respective currents of a plurality of variable load circuits.

54. An apparatus as set forth in claim 53, wherein the means for limiting the respective currents of a plurality of variable load circuits includes means for sharing the instantaneous current reserve.

55. An apparatus as set forth in claim 54, wherein the means for sharing the instantaneous current reserve includes means for sharing an instantaneous reserve current from the distributor.

56. An apparatus as set forth in claim 55, wherein the means for sharing an instantaneous reserve current includes means for multiplexing the instantaneous reserve current.

57. An apparatus as set forth in claim 31, wherein the distributor is a distribution panel.

58. An apparatus as set forth in claim 31, wherein the distributor is a distribution transformer.

59. An apparatus as set forth in claim 31, wherein the means for measuring the instantaneous current reserve of the distributor includes means for measuring the instantaneous current reserve of the distributor as the maximum rated current of the distributor less the instantaneous current flowing from the distributor in the phase corresponding to the phase of the variable load circuit.

60. An apparatus as set forth in claim 31, wherein:

(a) the distributor is configured for at least one of split-phase and multi-phase supply;

(b) the variable load circuit is configured as a two-phase load; and

(c) the means for measuring the instantaneous current reserve of the distributor includes means for measuring the instantaneous current reserve of the distributor as the maximum rated current of the distributor less the larger of the instantaneous current flowing from the distributor in each of the two phases supplying the variable load.