Devices and methods for converting alternating current (AC) power to direct current (DC) power

• US 8,780,586 B2
• Filed: 12/28/2012
• Issued: 07/15/2014
• Est. Priority Date: 11/16/2007
• Status: Active Grant

• Current Assignee: SmartSynch Incorporated (Itron, Inc.)
• Original Assignee: Itron, Inc.
• Inventors: Khan, Zafarullah
• Primary Examiner(s): Berhane, Adolf
• Assistant Examiner(s): Mehari, Yemane
• Application Number:
  US13/730,002
• Publication Number:
  US 20130188398A1
• Time in Patent Office: 564 Days
• Field of Search: 363/20, 363120-127, 323266-282, 323/284
• US Class Current: 363/20
• CPC Class Codes: H02M 1/007 Plural converter units in cascade push-pull DC/DC converters with pre-regulator H02M3/3374; DC-AC converters following a DC-DC stage including a high frequency transformer H02M7/4807; DC-AC converters following a DC-DC conversion stage generating periodically varying voltages H02M7/4826
• CPC Class Codes: H02M 7/217 using semiconductor devices only
• CPC Class Codes: H02M 7/2176 comprising a passive stage to generate a rectified sinusoidal voltage and a controlled switching element in series between such stage and the output

Abstract

Methods, circuit designs, systems, and devices for the conversion of high voltage alternating current (AC) to low voltage, high current direct current (DC) are described. An exemplary apparatus includes a rectifier for receiving a high voltage AC line power input and for outputting a full wave, high voltage DC, a gating component coupled to the rectifier for receiving the high voltage DC output by the rectifier, wherein the gating component is configured to gate the high voltage DC by turning on at a zero crossing level and turning off when the high voltage DC exceeds a preset voltage threshold and wherein the output of the gating component is an intermediate voltage DC capped by the preset voltage threshold, and a DC-DC converter coupled to the gating component for receiving the intermediate voltage DC output by the gating component, wherein the DC-DC converter is configured to step down and smooth out the intermediate voltage DC to a desired high current, low voltage DC output.

Claims

1. An apparatus to convert alternating current (AC) line power to direct current (DC) power, comprising:

a rectifier to receive a high voltage AC line power input and to output a full wave rectified high voltage DC;

a voltage-reducing voltage regulator coupled to the rectifier to receive the full wave rectified high voltage DC and to provide an intermediate voltage DC capped by a preset voltage threshold corresponding to the intermediate voltage DC, wherein the regulator is to supply the intermediate voltage DC by gating the full wave rectified high voltage DC at the preset voltage threshold; and

a voltage-reducing switching DC-DC converter directly coupled to the voltage-reducing regulator to receive the intermediate voltage DC provided by the voltage-reducing regulator,

the voltage-reducing DC-DC converter to step down and smooth out the intermediate voltage DC to a desired high current, low voltage DC output, the voltage-reducing regulator being coupled between the rectifier and the voltage-reducing DC-DC converter to isolate the full wave rectified high voltage DC from the voltage-reducing DC-DC converter, wherein the voltage-reducing regulator comprises a gating component to gate the high voltage DC by turning on at a zero crossing level and turning off when the high voltage DC exceeds the preset voltage threshold and remain off after the high voltage DC exceeds the preset voltage threshold and until a next zero crossing level.

2. The apparatus of claim 1, wherein the rectifier is a bridge rectifier.

3. The apparatus of claim 2, wherein the voltage-reducing regulator is operatively coupled to transistor switches.

4. The apparatus of claim 3, wherein the transistor switches comprise one or more of an enhancement mode MOSFET, a depletion mode MOSFET, a bipolar transistor, a photo transistor, an IGBT, an ESBT, or a silicon controlled rectifier (SCR).

5. The apparatus of claim 1, wherein the high voltage AC line power input to the rectifier is within the range of 60 to 480 voltage AC.

6. The apparatus of claim 1, wherein the high voltage AC line power input to the rectifier is within the range of 80 to 600 voltage AC.

7. The apparatus of claim 1, wherein the preset voltage threshold is 50 volts DC and the desired high current, low voltage DC output is approximately 4 volts DC at 1000 milliamperes (mA).

8. The apparatus of claim 1, wherein components of the voltage reducing DC-DC converter are rated to handle voltage levels up to the preset voltage threshold of the voltage-reducing regulator.

9. The apparatus of claim 1, wherein the voltage-reducing DC-DC converter includes:

an input capacitor to smooth out the intermediate voltage DC received from the voltage-reducing regulator;

a switch and a transformer to step down the intermediate voltage DC; and

an output capacitor to smooth out the stepped down intermediate voltage DC from the transformer to create the desired, high current, low voltage DC output.

10. The apparatus of claim 9, wherein a second output capacitor is coupled to an output of the voltage-reducing DC-DC converter to further smooth the high current, low voltage DC output.

11. The apparatus of claim 1, wherein the intermediate voltage DC is 50 volts DC.

12. The apparatus of claim 1, wherein the rectifier is to provide a high side and a low side for the full wave rectified high voltage DC, and wherein the voltage-reducing voltage regulator is coupled between the rectifier and the DC-DC converter on the high side.

13. An apparatus to convert an input high voltage DC to high current, low voltage DC, comprising:

a voltage-reducing voltage regulator to receive the input high voltage DC and to provide an intermediate voltage DC capped by a preset voltage threshold corresponding to the intermediate voltage DC, wherein the voltage-reducing regulator is to supply the intermediate voltage DC by gating the input high voltage DC at the preset voltage threshold; and

a voltage-reducing switching DC-DC converter coupled to the voltage-reducing regulator to receive the intermediate voltage DC output provided by the voltage-reducing regulator, the voltage-reducing DC-DC converter to step down and smooth out the intermediate voltage DC to a desired high current, low voltage DC output,

the voltage-reducing regulator being coupled directly to the voltage reducing DC-DC converter to isolate the input high voltage DC from the voltage reducing DC-DC converter, wherein the voltage-reducing regulator comprises a gating component to gate the input high voltage DC by turning on at a zero crossing level and turning off when the input high voltage DC exceeds the preset voltage threshold and remain off after the input high voltage DC exceeds the preset voltage threshold and until a next zero crossing level.

14. The apparatus of claim 13, wherein the voltage-reducing regulator is operatively coupled to transistor switches on a high side of the input high voltage DC.

15. The apparatus of claim 14, wherein the transistor switches comprise one or more of an enhancement mode MOSFET, a depletion mode MOSFET, a bipolar transistor, a photo transistor, an IGBT, an ESBT, or a silicon controlled rectifier (SCR).

16. The apparatus of claim 13, wherein the preset voltage threshold is 50 volts DC and the desired high current, low voltage DC output is approximately 4 volts DC at 1000 milliamperes (mA).

17. The apparatus of claim 13, wherein the voltage-reducing DC-DC converter includes:

an input capacitor to smooth out the intermediate voltage DC received from the voltage-reducing regulator;

a switch and a transformer to step down the intermediate voltage DC; and

an output capacitor to smooth out the stepped down intermediate voltage DC from the transformer to create the desired, high current, low voltage DC output.

18. The apparatus of claim 17, wherein a second output capacitor is coupled to an output of the voltage-reducing DC-DC converter to further smooth high current, low voltage DC output.

19. The apparatus of claim 13, wherein components of the voltage reducing DC-DC converter are rated to handle voltage levels up to the preset voltage threshold of the voltage-reducing regulator.

20. The apparatus of claim 13, wherein the input high voltage DC is a full wave rectified high voltage DC.

21. The apparatus of claim 13, wherein the intermediate voltage DC is 50 volts DC.

22. The apparatus of claim 13, wherein the input high voltage DC comprises a high side and a low side, and wherein the voltage-reducing voltage regulator is coupled between the input high voltage DC and the DC-DC converter on the high side.

23. A method to convert alternating current (AC) line power to low voltage direct current (DC) power, comprising:

rectifying a high voltage AC line power input to provide a full wave rectified high voltage DC;

coupling the full wave rectified high voltage DC directly to an isolating intermediate voltage regulator;

continuously regulating the full wave rectified high voltage DC with the isolating intermediate voltage regulator to provide a regulated intermediate voltage DC capped at a preset voltage threshold;

directly coupling the regulated intermediate voltage DC to a voltage-reducing low voltage DC-DC switching power supply;

providing a desired, high current, low voltage DC output from the voltage-reducing low voltage DC-DC switching power supply, wherein the isolating intermediate voltage regulator isolates the high voltage AC line power from the voltage-reducing low voltage switching power supply with a regulated intermediate voltage DC; and

gating the full wave rectified high voltage DC by turning on a switch at a zero crossing level and turning off the switch when the high voltage DC exceeds the preset voltage threshold, thereby outputting a series of intermediate voltage DC waves capped by the preset voltage threshold, and the switch remaining off after the full wave, high voltage DC exceeds the preset voltage threshold and until a next zero crossing level.

24. The method of claim 23, further comprising:

stepping down the series of intermediate voltage DC waves to a lower voltage DC; and

smoothing AC ripples in the series of intermediate voltage DC waves prior to stepping down the intermediate voltage DC to the lower voltage DC.

25. The method of claim 23, wherein providing the regulated intermediate voltage DC protects electronic components responsible for stepping down and smoothing AC ripples.

26. The method of claim 25, wherein the components responsible for stepping down and smoothing AC ripples are rated to withstand voltages up to the preset voltage threshold.

27. The method of claim 23, further comprising providing the desired, high current, low voltage DC output to electronic components.

28. The method of claim 23, wherein the full wave rectified high voltage DC comprises a high side and a low side, and wherein continuously regulating the full wave rectified high voltage DC is effected by the isolating voltage-reducing voltage regulating component coupled between the high side of the full wave rectified high voltage DC and the voltage-reducing low voltage switching power supply.