Buck-boost DC-DC switching power conversion

• US 20040239299A1
• Filed: 07/06/2004
• Published: 12/02/2004
• Est. Priority Date: 08/08/2002
• Status: Active Grant

• Current Assignee: Vicor Corporation
• Original Assignee: VLT Incorporated (Vicor Corporation)
• Inventors: Vinciarelli, Patrizio
• Granted Patent: US 7,154,250 B2
• Time in Patent Office: Days
• US Class Current: 323/282
• CPC Class Codes: H02M 3/1582 Buck-boost converters H02M3/1584 takes precedence

Abstract

Apparatus operates at a power level within a range of power levels that includes a rated maximum power level of the apparatus. The apparatus includes circuit elements to deliver power at an output voltage to a load from a source at an input voltage using an inductor selectively connected between the source and the load during a power conversion cycle. The inductor conducts a current having an average positive value during the power conversion cycle. A first switching device is interposed between the source and a first terminal of the inductor. A second switching device is interposed between a second terminal of the inductor and the load. A switch controller turns ON the first switching device during a time interval within the power conversion cycle during which the current is negative.

Claims

1-33. -33. (Cancelled)

34. Apparatus comprising

a buck-boost converter to operate at a power level within a range of power levels including a rated maximum power level of the apparatus, and

a DC transformer to deliver an output voltage to a load,

the buck-boost converter comprising

circuit elements to deliver power to the DC transformer from a source at an input voltage using an inductor selectively connected between the source and the DC transformer during a power conversion cycle, the inductor conducting a current having an average positive value during the power conversion cycle,

a first switching device interposed between the source and a first terminal of the inductor,

a second switching device interposed between a second terminal of the inductor and the DC transformer, and

a switch controller to turn ON the first switching device during a time interval within the power conversion cycle during which the current in the inductor is negative.

35. The apparatus of claim 34 in which the DC transformer is incorporated in a VTM, the buck-boost converter is incorporated in a PRM, and power is delivered from the PRM to the VTM by a factorized bus.

36. The apparatus of claim 34 in which the output voltage of the DC transformer is connected in a feedback configuration to control an operating condition of the buck-boost converter.

37. Apparatus to operate at a power level within a range of power levels including a rated maximum power level of the apparatus, the apparatus comprising,

circuit elements for delivering power at an output voltage to a load from a source at an input voltage by selectively connecting an external inductor between the source and the load during a power conversion cycle, the inductor conducting a current having an average positive value during the power conversion cycle,

a first switching device coupled to the source and having a port to connect to a first terminal of the inductor,

a second switching device coupled to the load and having a port to connect to a second terminal of the inductor, and

a switch controller to turn ON the first switching device during a time interval within the power conversion cycle during which the current is negative.

38. The apparatus of claim 37 also including the inductor.

39. The apparatus of claim 37 comprising an integrated semiconductor device.

40. Apparatus comprising

a buck-boost power converter to operate at a power level within a range of power levels including a rated maximum power level of the apparatus,

the buck-boost converter comprising

circuit elements to deliver power to a load at an output voltage from an AC source at an input voltage using an inductor selectively connected between the source and the load during a power conversion cycle, the inductor conducting a current having an average positive value during the power conversion cycle,

a first switching device interposed between the source and a first terminal of the inductor,

a second switching device interposed between a second terminal of the inductor and the load,

a switch controller to turn ON the first switching device during a time interval within the power conversion cycle during which the current is negative, and

a power factor controller connected to the switch controller to cause the switch controller to control the harmonic content of an input current from the AC source while regulating the output voltage.

41. The apparatus of claim 40 in which the power factor controller receives an input current of the AC source and the output voltage as input signals.

42. Apparatus comprising

a battery, and

a power converter connected between the battery and a load to operate at a power level within a range of power levels including a rated maximum power level of the apparatus, the power converter comprising

circuit elements to deliver power at an output voltage to the load from the battery at an input voltage using an inductor selectively connected between the battery and the load during a power conversion cycle, the inductor conducting a current having an average positive value during the power conversion cycle,

a first switching device interposed between the battery and a first terminal of the inductor,

a second switching device interposed between a second terminal of the inductor and the load, and

a switch controller to turn ON the first switching device during a time interval within the power conversion cycle during which the current is negative.

43. Apparatus comprising

a buck-boost power converter including (a) a first port to connect to terminals of a device across which a voltage may vary in response to current transients, (b) a second port to connect to a device that stores and releases energy, (c) an inductor to transfer energy between the first port and the second port, the first port and the second port serving selectively as either a source and a load or as a load and a source, (d) switching devices to selectively connect the inductor between any two of the source, the load, and a ground, (e) a switch controller to turn the switching devices ON and OFF in a sequence to cause power to be converted from the source to the load in either a buck mode or a boost mode, and (d) a port to receive a control input that controls whether the first port and the second port are serving respectively as either the source and the load or as the load and the source.

44. The apparatus of claim 43 also including the device that stores and releases energy.

45. The apparatus of claim 43 in which the device that stores and releases energy comprises a capacitor.

46. Apparatus comprising

circuit elements to deliver power at an output voltage to a load from a source at an input voltage using an inductor selectively connected between the source and the load during a power conversion cycle, the inductor conducting a current having an average positive value during the power conversion cycle,

a first switching device interposed between the source and a first terminal of the inductor,

a second switching device interposed between a second terminal of the inductor and the load,

a switch controller to turn ON the first switching device during a time interval within the power conversion cycle during which the current is negative.

a first port to connect to terminals of an operating device across which a voltage may vary in response to current transients,

a second port to connect to a storage device that stores and releases energy,

the operating device and the storage device serving selectively either as a source and a load or as a load and a source, and

a port to receive a control input that controls whether the first port and the second port are serving respectively as either the source and the load or as the load and the source.

47. Apparatus adapted to share power within a range of power levels that includes a rated maximum power level of the apparatus, the apparatus comprising

circuit elements to deliver power at an output voltage to a load from a source at an input voltage using an inductor selectively connected between the source and the load during a power conversion cycle of a succession of power conversion cycles, the inductor conducting a current having an average positive value during the power conversion cycle and having a negative value during a time interval within the power conversion cycle,

a paralleling port to emit or receive from a paralleling bus a paralleling pulse in a succession of paralleling pulses, and

a control circuit to synchronize the succession of power conversion cycles to the succession of paralleling pulses.

48. The apparatus of claim 47 in which the paralleling pulse has a rising edge, a falling edge and a pulse width and the control circuit adjusts parameters of the power conversion cycle to parameters of the paralleling pulse.

49. Apparatus for converting power from an input source at an input voltage for delivery to an output at an output voltage, comprising:

an inductor,

first and second switches connected to a first terminal of the inductor and a third switch connected to a second terminal of the inductor,

a switch controller adapted to operate the switches in a series of converter operating cycles, each converter operating cycle including,

(i) an input (“

IN”

) phase during which the inductor is connected across the source for a time T_IN,

(ii) a input-output (“

IO”

) phase during which the inductor is connected between the source and the output for a time T_IO,

(iii) a free-wheel (“

FW”

) phase during which the inductor is connected across the output for a time T_FW,

(iv) a clamp (“

CL”

) phase during which the inductor is shorted for a time T_CL,

wherein the end of each converter operating cycle marks the beginning of another converter operating cycle.

50. The apparatus of claim 49 wherein each converter operating cycle comprises a sequence in which the IN phase occurs before the IO phase, the IO phase occurs before the FW phase, and the FW phase occurs before the CL phase.

51. The apparatus of claim 50 wherein the switch controller is adapted to adjust the duration of T_IN, T_IO, T_FW, or T_CL.

52. The apparatus of claim 51 wherein each converter operating cycle comprises an energy recycling interval following at least one of the IN, IO, FW, or CL phases.

53. The apparatus of claim 49 or 52 wherein each converter operating cycle further comprises:

a first energy recycling interval following the IN phase,

a second energy recycling interval following the IO phase,

a third energy recycling interval following the FW phase, and

a fourth energy recycling interval following the CL phase,

wherein a parasitic capacitance of a selected switch is charged or discharged using current flowing in the inductor.

54. The apparatus of claim 50 further comprising a unidirectional conduction device connected to the second terminal.

55. The apparatus of claim 54 wherein the unidirectional conduction device is connected between the second terminal and the load.

56. The apparatus of claim 50 further comprising a fourth switch connected to the second terminal.

57. The apparatus of claim 56 wherein the fourth switch is connected between the second terminal and the load.

58. The apparatus of claim 50 or 56 wherein the switches comprise MOSFETs.

59. Apparatus for converting power from an input source at an input voltage for delivery to an output at an output voltage, comprising:

an inductor,

first and second switches connected to a first terminal of the inductor and a third switch connected to a second terminal of the inductor,

a switch controller adapted to operate the switches in a series of converter operating cycles, each converter operating cycle including;

(i) an input (“

IN”

) phase during which the inductor is connected across the source for a time T_IN,

(ii) a input-output (“

IO”

) phase during which the inductor is connected between the source and the output for a time T_IO,

(iii) a free-wheel (“

FW”

) phase during which the inductor is connected across the output for a time T_FW,

wherein each converter operating cycle includes exactly one of each of the IN, IO, and FW phases, each IN, IO, and FW phase is uninterrupted, and the end of each converter operating cycle marks the beginning of another converter operating cycle.

60. The apparatus of claim 59 wherein each converter operating cycle further comprises a clamp (“

CL”

) phase during which the inductor is shorted for a time T_CL.

61. The apparatus of claim 59 wherein each converter operating cycle comprises a sequence in which the IN phase occurs before the IO phase and the IO phase occurs before the FW phase.

62. (Added) The apparatus of claim 61 wherein the switch controller is adapted to adjust the duration of T_IN, T_IO, or T_FW.

63. The apparatus of claim 59 wherein the input voltage may vary over a normal operating range between a minimum input voltage and a maximum input voltage and each converter operating cycle includes the IN, IO, and FW phases-throughout the normal operating range.

64. The apparatus of claim 59 or 62 wherein each converter operating cycle further comprises:

a first energy recycling interval following the IN phase,

a second energy recycling interval following the IO phase,

a third energy recycling interval following the FW phase, and

a fourth energy recycling interval following the FW phase,

wherein a parasitic capacitance of a selected switch is charged or discharged using current flowing in the inductor.

65. The apparatus of claim 59 further comprising a unidirectional conduction device connected to the second terminal.

66. The apparatus of claim 65 wherein the unidirectional conduction device is connected between the second terminal and the load.

67. The apparatus of claim 59 further comprising a fourth switch connected to the second terminal.

68. The apparatus of claim 67 wherein the fourth switch is connected between the second terminal and the load.

69. The apparatus of claim 59 or 67 wherein the switches comprise MOSFETs.

70. The apparatus of claim 49 or 59 wherein a current, I_L, flows in the inductor and the current returns to zero during each converter operating cycle.

71. The apparatus of claim 49 or 59 wherein a current, I_L, flows in the inductor and the current reverses direction during each converter operating cycle.