AC-to-DC converter circuit utilizing IGBT's for improved efficiency

• US 6,549,438 B2
• Filed: 04/30/2001
• Issued: 04/15/2003
• Est. Priority Date: 04/30/2001
• Status: Expired due to Fees

• Current Assignee: Precision Automation Incorporated
• Original Assignee: Precision Automation Incorporated
• Inventors: Malone, Douglas J.
• Primary Examiner(s): STERRETT, JEFFREY L
• Application Number:
  US09/845,718
• Publication Number:
  US 20020159279A1
• Time in Patent Office: 715 Days
• Field of Search: 363/89, 363/127
• US Class Current: 363/89
• CPC Class Codes: H02M 1/0085 Partially controlled bridges
• CPC Class Codes: H02M 1/32 Means for protecting converters other than automatic disconnection
• CPC Class Codes: H02M 7/217 using semiconductor devices only

Abstract

An AC-to-DC converter furnishing a regulated DC-output voltage from an AC-input supply voltage which is converted with a rectifier that utilizes, in at least two of its legs, IGBT (insulated gate bipolar transistor) devices, preferably of the kind that have no internal diodes. Also included in the converter of this convention is circuitry which tracks zero-crossing events relative to AC-input voltage for the purpose of establishing switching signals and times for such signals for operating the IGBT devices, and wherein thorough-safe operation is associated with malfunctioning of the zero-crossing tracking subcircuitry whereby a failure in that circuitry will result effectively in a shut down of the entire converter, and a bleed down to zero of DC-output voltage.

Claims

1. An AC-DC converter comprising

AC input terminals,

DC output terminals, and

intermediate said AC and DC terminals,

a bridge rectifier operatively interposed said terminals, and including a first pair of legs connected in series and a second pair of legs connected in series, wherein the first pair of legs is immediately adjacent to and connected in parallel to the second pair of legs, and wherein each leg of the first pair of legs includes an insulated-gate bipolar transistor (IGBT) independent of a diode and each leg of the second pair of legs contains a diode independent of an IGBT.

2. The converter of claim 1, wherein each IGBT device is one which lacks an internal body diode.

3. An AC-to-DC converter comprising:

AC input terminals,

DC output terminals, and

an interactive-behavior circuit loop including

operative connections to said AC and DC terminals, and in addition,

a rectifier operatively interposed said terminals, and including a first pair of legs connected in series and a second pair of legs connected in series, wherein the first pair of legs is immediately adjacent to and connected in parallel to the second pair of legs, and wherein each leg of the first pair of legs includes an insulated-gate bipolar transistor (IGBT) independent of a diode and each leg of the second pair of legs contains a diode independent of an IGBT,

a DC output-voltage level-monitoring circuit operatively interposed said DC output terminals and said rectifier, and

a zero-crossing tracker operatively interposed said AC input terminals and said level-monitoring circuit.

4. A regulated-voltage AC-to-DC converter comprising

AC input terminals,

DC output terminals,

a bridge rectifier including a first pair of legs connected in series and a second pair of legs connected in series, wherein the first pair of legs is immediately adjacent to and connected in parallel to the second pair of legs, and wherein each leg of the first pair of legs includes an insulated-gate bipolar transistor (IGBT) independent of a diode and each leg of the second pair of legs contains a diode independent of an IGBT, and

a DC output-voltage-level monitoring circuit operatively interposed said output terminals and said IGBT devices, operable to effect switching of said devices in response to DC output voltage level, and in a manner tending to maintain output-level-constancy of that output voltage.

5. The converter of claim 4, wherein an operative connection exists between said monitoring circuit and said IGBT switching devices via opto-isolator structure.

6. The converter of claim 5 which further includes a zero-crossing tracker operatively connected to said input terminals and to said monitoring circuit, effective to control the operation of at least a portion of the monitoring circuit.

7. An AC-to-DC converter comprising

AC input terminals,

DC output terminals,

a rectifier operatively interposed said terminals, and including a first pair of legs connected in series and a second pair of legs connected in series, wherein the first pair of legs is immediately adjacent to and connected in parallel to the second pair of legs, and wherein each leg of the first pair of legs includes an insulated-gate bipolar transistor (IGBT) independent of a diode and each leg of the second pair of legs contains a diode independent of an IGBT,

a zero-crossing tracker operatively connected to said input terminals, and

circuit structure operatively interconnecting said rectifier and said zero-crossing tracker, responsive to cessation of normal operation of said tracker to disable the functionality of said rectifier circuit, thus to close off the supply of DC output voltage from said rectifier circuit to said DC output terminals.

8. The converter of claim 7, wherein said circuit structure includes a flip-flop circuit.

9. The converter of claim 7, wherein said rectifier circuit includes insulated-gate bipolar transistor (IGBT) switching/rectifying devices.