System and method for proportioned power distribution in power converter arrays

• US 9,397,502 B2
• Filed: 06/19/2013
• Issued: 07/19/2016
• Est. Priority Date: 03/02/2009
• Status: Active Grant

• Current Assignee: Volterra Semiconductor Corporation (Analog Devices, Inc.)
• Original Assignee: Volterra Semiconductor LLC (Analog Devices, Inc.)
• Inventors: Weir, Steve, Macris, Eric, Lawrence, Eric
• Primary Examiner(s): Wells, Kenneth B
• Assistant Examiner(s): Pacheco, Rafael
• Application Number:
  US13/922,202
• Publication Number:
  US 20140035371A1
• Time in Patent Office: 1,126 Days
• US Class Current: 1/1
• CPC Class Codes: B60L 2210/12 Buck converters
• CPC Class Codes: B60L 2210/14 Boost converters
• CPC Class Codes: B60L 2240/545 Temperature
• CPC Class Codes: B60L 2240/547 Voltage
• CPC Class Codes: B60L 2240/549 Current
• CPC Class Codes: B60L 3/003 relating to inverters
• CPC Class Codes: B60L 3/0046 relating to electric energy storage systems, e.g. batteries or capacitors
• CPC Class Codes: B60L 3/0069 relating to the isolation, e.g. ground fault or leak current
• CPC Class Codes: B60L 3/04 Cutting off the power supply under fault conditions protective devices and circuit arrangements in general H01H; H02H
• CPC Class Codes: B60L 50/16 with provision for separate direct mechanical propulsion
• CPC Class Codes: B60L 50/40 using propulsion power supplied by capacitors
• CPC Class Codes: B60L 58/10 for monitoring or controlling batteries
• CPC Class Codes: B60L 58/18 of two or more battery modules
• CPC Class Codes: B60L 58/22 Balancing the charge of battery modules
• CPC Class Codes: B60L 7/14 for vehicles propelled by ac motors
• CPC Class Codes: H02J 4/00 Circuit arrangements for mains or distribution networks not specified as ac or dc
• CPC Class Codes: H02J 7/0014 Circuits for equalisation of charge between batteries
• CPC Class Codes: H02J 7/0025 Sequential battery discharge in systems with a plurality of batteries
• CPC Class Codes: H02M 1/0077 Plural converter units whose outputs are connected in series
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 : Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• CPC Class Codes: Y02T 10/72 : Electric energy management in electromobility
• CPC Class Codes: Y02T 10/92 : Energy efficient charging or discharging systems for batteries, ultracapacitors, supercapacitors or double-layer capacitors specially adapted for vehicles
• CPC Class Codes: Y02T 90/16 : Information or communication technologies improving the operation of electric vehicles

Abstract

A system and method for proportioned power distribution in arrays of power converters are disclosed. According to one embodiment, a method includes distributing a node-specific transfer function to each node of a plurality of nodes via a communication bus. Each node includes a power converter, and nodes of the plurality of nodes are electrically connected in series. Each node-specific transfer function enables each node to contribute a positive impedance to a total impedance of the plurality of nodes. The computer-implemented method further includes coordinating a setting of a parameter of each node-specific transfer function to regulate a common bus current across the plurality of nodes, and assigning to each node an electrical characteristic based on a parameter of each node-specific transfer function.

Claims

1. A method, comprising:

distributing a node-specific transfer function to each node of a plurality of nodes via a communication bus, wherein each node comprises a power converter circuit, wherein nodes of the plurality of nodes are electrically connected in series, and wherein each node-specific transfer function enables each node to contribute a positive impedance to a total impedance of the plurality of nodes;

coordinating a setting of a parameter of each node-specific transfer function for the plurality of nodes to regulate a common bus current across the plurality of nodes; and

assigning to each node an electrical characteristic based on the parameter of each node-specific transfer function.

2. The method of claim 1, wherein the node-specific transfer function comprises one or more of a first current component that is common to the plurality of nodes, a node-specific voltage coefficient that is linearly related to the assigned electrical characteristic, and a node-specific resistance coefficient that relates to the node-specific voltage coefficient by a scaling coefficient, wherein the scaling coefficient for the plurality of nodes is common.

3. The method of claim 1, wherein the power converter circuit comprises one or more switched-mode power supplies.

4. The method of claim 2, wherein the node-specific transfer function comprises a second current component based on a difference between a cycle-by-cycle average current and a peak current in the power converter circuit.

5. The method of claim 2, further comprising selecting a minimum node-specific resistance value and a capacitance value of a filter capacitor based on a power converter control loop bandwidth, wherein the filter capacitor is part of the node.

6. The method of claim 1, further comprising varying the assigned electrical characteristic at arbitrary times while maintaining continuous stable operation.

7. The method of claim 2, wherein the node-specific voltage coefficient is further based on a nominal efficiency of the power converter circuit.

8. The method of claim 2, further comprising distributing one or more of the first current component, the node-specific voltage coefficient and the node-specific resistance coefficient via one or more of digital and analog communication means.

9. The method of claim 2, further comprising adjusting one or more of the first current component, the node-specific voltage coefficient and the node-specific resistance coefficient to correct a difference between a measured electrical characteristic across the node and the assigned electrical characteristic.

10. The method of claim 1, wherein the electrical characteristic comprises one of a voltage, an energy over time, and a proportion of an aggregate power across the plurality of nodes.

11. The method of claim 2, wherein determining the first current component is based on a minimum given current flowing through the plurality of nodes.

12. The method of claim 2, wherein two or more pluralities of nodes are electrically connected in parallel.

13. The method of claim 12, wherein the first current component is linearly related to an assigned fraction of an aggregate power across the two or more pluralities of nodes.

14. The method of claim 13, wherein a sum total of node-specific voltage coefficients for each plurality of nodes is common to the two or more pluralities of nodes that are electrically connected in parallel.

15. The method of claim 14, wherein the scaling coefficient is inversely proportional to the first current component that is common to the plurality of nodes.

16. The method of claim 14, wherein the scaling coefficient is proportional to a maximum first current component of two or more first current components.

17. The method of claim 1, wherein each node comprises an energy storage cell electrically connected to the power converter circuit.

18. The method of claim 17, further comprising determining the assigned proportion of the aggregate power of the plurality of nodes based on one or more of historical energy storage cell characteristics, energy storage cell degradation characteristics, energy storage cell performance characteristics, and predicted energy storage cell performance characteristics.

19. A non-transitory computer-readable medium having stored thereon computer-readable instructions, and a processor coupled to the non-transitory computer readable medium, wherein the processor executes the instructions:

distribute a node-specific transfer function to each node of a plurality of nodes via a communication bus, wherein each node comprises a power converter circuit, wherein nodes of the plurality of nodes are electrically connected in series, and wherein each node-specific transfer function enables each node to contribute a positive impedance to a total impedance of the plurality of nodes;

coordinate a setting of a parameter of each node-specific transfer function for the plurality of nodes to regulate a common bus current across the plurality of nodes; and

assign to each node an electrical characteristic based on the parameter of each node-specific transfer function.

20. The non-transitory computer-readable medium of claim 19, wherein the node-specific transfer function comprises one or more of a first current component that is common to the plurality of nodes, a node-specific voltage coefficient that is linearly related to the assigned electrical characteristic, and a node-specific resistance coefficient that relates to the node-specific voltage coefficient by a scaling coefficient, wherein the scaling coefficient for the plurality of nodes is common.

21. The non-transitory computer-readable medium of claim 19, wherein the power converter circuit comprises one or more switched-mode power supplies.

22. The non-transitory computer-readable medium of claim 20, wherein the node-specific transfer function comprises a second current component based on a difference between a cycle-by-cycle average current and a peak current in the power converter circuit.

23. The non-transitory computer-readable medium of claim 20, wherein the processor executes the instructions to select a minimum node-specific resistance value based on a power converter control loop bandwidth and a given capacitance value of a filter capacitor, wherein the filter capacitor is part of the node.

24. The non-transitory computer-readable medium of claim 19, wherein the processor executes the instructions to vary the assigned electrical characteristic at arbitrary times while maintaining continuous stable operation.

25. The non-transitory computer-readable medium of claim 20, wherein the node-specific voltage coefficient is further based on a nominal efficiency of the power converter circuit.

26. The non-transitory computer-readable medium of claim 20, wherein the processor executes the instructions to distribute one or more of the first current component, the node-specific voltage coefficient and the node-specific resistance coefficient via one or more of digital and analog communication means.

27. The non-transitory computer-readable medium of claim 20, wherein the processor executes the instructions to adjust one or more of the first current component, the node-specific voltage coefficient and the node-specific resistance coefficient to correct a difference between a measured electrical characteristic across the node and the assigned electrical characteristic.

28. The non-transitory computer-readable medium of claim 19, wherein the electrical characteristic comprises one of a voltage, an energy over time, and a proportion of an aggregate power across the plurality of nodes.

29. The non-transitory computer-readable medium of claim 20, wherein the processor executes the instructions to determine the first current component based on a minimum given current flowing through the plurality of nodes.

30. The non-transitory computer-readable medium of claim 20, wherein two or more pluralities of nodes are electrically connected in parallel.

31. The non-transitory computer-readable medium of claim 30, wherein the first current component is linearly related to an assigned fraction of an aggregate power across the two or more pluralities of nodes.

32. The non-transitory computer-readable medium of claim 31, wherein a sum total of node-specific voltage coefficients for each plurality of nodes is common to the two or more pluralities of nodes that are electrically connected in parallel.

33. The non-transitory computer-readable medium of claim 32, wherein the scaling coefficient is inversely proportional to the first current component that is common to the plurality of nodes.

34. The non-transitory computer-readable medium of claim 32, wherein the scaling coefficient is proportional to a maximum first current component of two or more first current components.

35. The non-transitory computer-readable medium of claim 19, wherein each node comprises an energy storage cell electrically connected to the power converter circuit.

36. The non-transitory computer-readable medium of claim 35, wherein the processor executes the instructions to determine the assigned proportion of the aggregate power of the plurality of nodes based on one or more of historical energy storage cell characteristics, energy storage cell degradation characteristics, energy storage cell performance characteristics, and predicted energy storage cell performance characteristics.

37. A system, comprising:

a plurality of nodes, wherein a node of the plurality of nodes comprises a power converter circuit; and

wherein nodes of the plurality of nodes are electrically connected in series;

a central processor in communication with the plurality of nodes by registers, wherein the central processor;

distributes a node-specific transfer function to each node of a plurality of nodes via a communication bus, wherein each node comprises a power converter circuit, wherein nodes of the plurality of nodes are electrically connected in series, and wherein each node-specific transfer function enables each node to contribute a positive impedance to a total impedance of the plurality of nodes;

coordinates a setting of a parameter of each node-specific transfer function for the plurality of nodes to regulate a common bus current across the plurality of nodes; and

assigns to each node an electrical characteristic based on the parameter of each node-specific transfer function.

38. The system of claim 37, wherein the node-specific transfer function comprises one or more of a first current component that is common to the plurality of nodes, a node-specific voltage coefficient that is linearly related to the assigned electrical characteristic, and a node-specific resistance that relates to the node-specific voltage coefficient by a scaling coefficient, wherein the scaling coefficient for the plurality of nodes is common.

39. The system of claim 37, wherein the power converter circuit comprises one or more switched-mode power supplies.

40. The system of claim 38, wherein the node-specific transfer function comprises a second current component based on a difference between a cycle-by-cycle average current and a peak current in the power converter circuit.

41. The system of claim 38, wherein the central processor selects a minimum node-specific resistance value based on a power converter control loop bandwidth and a given capacitance value of a filter capacitor, wherein the filter capacitor is part of the node.

42. The system of claim 37, wherein the central processor varies the assigned electrical characteristic at arbitrary times while maintaining continuous stable operation.

43. The system of claim 38, wherein the node-specific voltage coefficient is further based on a nominal efficiency of the power converter circuit.

44. The system of claim 38, wherein the central processor distributes one or more of the first current component, the node-specific voltage coefficient and the node-specific resistance coefficient via one or more of digital and analog communication means.

45. The system of claim 38, wherein the central processor adjusts one or more of the first current component, the node-specific voltage coefficient and the node-specific resistance coefficient to correct a difference between a measured electrical characteristic across the node and the assigned electrical characteristic.

46. The system of claim 37, wherein the electrical characteristic comprises one of a voltage, an energy over time, and a proportion of an aggregate power across the plurality of nodes.

47. The system of claim 38, wherein the central processor determines the first current component based on a minimum given current flowing through the plurality of nodes.

48. The system of claim 38, wherein two or more pluralities of nodes are electrically connected in parallel.

49. The system of claim 48, wherein the first current component is linearly related to an assigned fraction of an aggregate power across the two or more pluralities of nodes.

50. The system of claim 49, wherein a sum total of node-specific voltage coefficients for each plurality of nodes is common to the two or more pluralities of nodes that are electrically connected in parallel.

51. The system of claim 50, wherein the scaling coefficient is inversely proportional to the first current component that is common to the plurality of nodes.

52. The system of claim 50, wherein the scaling coefficient is proportional to a maximum first current component of two or more first current components.

53. The system of claim 37, wherein each node comprises an energy storage cell electrically connected to the power converter circuit.

54. The system of claim 53, wherein the central processor determines the assigned proportion of the aggregate power of the plurality of nodes based on one or more of historical energy storage cell characteristics, energy storage cell degradation characteristics, energy storage cell performance characteristics, and predicted energy storage cell performance characteristics.