Compact, configurable power supply for energizing ozone-producing cells

Patent metadata

Field	Value
Publication number	US-9302912-B2
Application number	US-201213432415-A
Country	US
Kind code	B2
Filing date	Mar 28, 2012
Priority date	Mar 28, 2012
Publication date	Apr 5, 2016
Grant date	Apr 5, 2016

Abstract

Improvements in the supply of high-frequency electrical power to ozone-producing cells can be accomplished using the systems and techniques described herein. Application of a DC-DC converter operating at a switching frequency substantially greater than a load frequency, supports generation of a high-voltage AC for powering such cells, while allowing for reductions in component size and reductions in a quality factor of a load tuning circuit. Controllable power inverters used in obtaining one or more of the switching and load frequencies can be controlled using feedback techniques to provide stable, high-quality power to ozone-producing cells under variations in one or more of externally supplied power and load conditions. An inrush protection circuit can also be provided to selectively introduce a current-limiting resistance until an input DC bus has been sufficiently initialized as determined by measurements obtained from the DC bus. The current limiting resistance can be a positive-temperature coefficient thermistor.

First claim

We claim:

1. A method for supplying power to at least one ozone-producing cell, comprising:
receiving an unregulated DC voltage;
switching the unregulated DC voltage at a first switching frequency;
converting the switched DC voltage to a regulated, DC high voltage, substantially greater than the unregulated DC voltage;
switching the DC high voltage at a second switching frequency within a preferred operating frequency range of the at least one ozone-producing cell;
coupling the switched DC high voltage to the at least one ozone-producing cell through a series inductance, the series inductance forming together with an internal capacitance of the at least one ozone-producing cell, a resonance adapted to subject the at least one ozone-producing cell to a narrow-band, AC high voltage within the preferred operating frequency range of the ozone-producing cell; and
providing a load power adjustment signal for setting a value of power to be delivered to the at least one ozone-producing cell, the load power adjustment signal being used to alter a voltage level of the DC high voltage.

2. The method of claim 1 , wherein the DC high voltage is between about 1 kV and about 2 kV, for the unregulated DC voltage obtained by rectification of utility-provided AC power.

3. The method of claim 1 , wherein converting the switched DC voltage to a regulated, DC high voltage comprises applying the switched DC voltage to a primary winding of a step-up transformer, a physical size of the step-up transformer being inversely proportional to the first switching frequency.

4. The method of claim 1 , wherein the first switching frequency is greater than about 300 kHz.

5. The method of claim 1 , wherein the preferred operating frequency range of the ozone-producing cell is between about 20 kHz and about 40 kHz.

6. The method of claim 5 , wherein the AC high voltage is about 8 kV peak-to-peak.

7. The method of claim 6 , wherein a Q resulting from the series inductance and the internal capacitance of the at least one ozone-producing cell is less than about 5.

8. The method of claim 1 , wherein switching one or more of the unregulated DC voltage and the DC high voltage comprises phase shift zero voltage switch pulse width modulation.

9. The method of claim 8 , further comprising switching one or more of the unregulated DC voltage and the DC high voltage responsive to a predetermined power for driving the at least one ozone-producing cell.

10. The method of claim 1 , further comprising adjusting the DC high voltage respective to an adjustable output power.

11. The method of claim 1 , wherein providing a load power adjustment signal comprises a user manually providing the load power adjustment signal.

12. A power converter for energizing at least one ozone-producing cell comprising:
a DC-to-DC converter having an input configured to receive an unregulated DC voltage and an output configured to provide a regulated DC high voltage derived from the unregulated DC voltage, the DC high voltage having an amplitude substantially greater than an amplitude of the unregulated DC voltage;
a high-frequency power inverter having an input in communication with the output of the DC-to-DC converter, the high-frequency power inverter configured to provide at an output a high-frequency AC voltage derived from the DC high voltage;
a series inductance coupled between the output of the high-frequency power inverter and at least one ozone-producing cell, the series inductance forming together with an internal capacitance of the at least one ozone-producing cell a resonance in the high-frequency AC voltage occurring within a preferred operating frequency range of the at least one ozone-producing cell; and
an input for providing a load power adjustment signal for setting a value of power to be delivered to the at least one ozone-producing cell, the load power adjustment signal being used to alter the amplitude of the DC high voltage based on the power to be delivered to the at least one ozone-producing cell.

13. The power converter of claim 12 , wherein the DC high voltage is between about 1 kV and about 2 kV, for the unregulated DC voltage obtained by rectification of utility-provided AC power.

14. The power converter of claim 12 , wherein each of the DC-to-DC converter and the high-frequency power inverter comprises a respective plurality of controllable switches, each plurality of controllable switches operated at a respective switching frequency.

15. The power converter of claim 14 , wherein the DC-to-DC converter comprises a step-up transformer having a physical size selected in inverse proportion to the respective switching frequency of the respective plurality of controllable switches.

16. The power converter of claim 15 , wherein the respective switching frequency of the plurality of controllable switches of the DC-to-DC converter is greater than about 300 kHz.

17. The power converter of claim 12 , further comprising:
a first controller having a sensing input receiving an indication of the DC high voltage output of the DC-to-DC converter, a reference input configured to receive an indication of a target DC high voltage, and a controlling output in communication with the DC-to-DC converter, the first controller configured to adjust operation of the DC-to-DC converter responsive to the target DC high voltage and an indication of the DC high voltage received at the sensing input; and
a second controller having a sensing input configured to receive an output indication of at least one of a load voltage and a load current supplied to the at least one ozone-producing cell, a reference power input configured to receive an indication of operating load power, and a controlling output in communication with the high frequency power inverter, the second controller configured to adjust operation of the high-frequency power inverter responsive to the received indication of operating load power and an indication of the at least one of the load voltage and the load current.

18. The power converter of claim 17 , wherein the second controller comprises a target DC high voltage output in communication with the reference input of the first controller.

19. The power converter of claim 17 , wherein at least one of the first and second controllers comprises a phase-shift, zero-voltage switch pulse width modulator.

20. The power converter of claim 12 , wherein the preferred operating frequency of the ozone-producing cell is between about 20 kHz and about 40 kHz.

21. The power converter of claim 12 , further comprising a shunt capacitance coupled in parallel to the at least one ozone-producing cell, a value of the shunt capacitance selectable to offset internal capacitance of added or removed ozone-producing cells, thereby preserving a substantially constant reactive load to the power converter.

22. The power converter of claim 12 , wherein the load power adjustment signal can be manually provided via the input by a user.

23. A method for supplying power to at least one ozone-producing cell, comprising:
converting an unregulated DC voltage to a regulated DC high voltage having an amplitude substantially greater than an amplitude of the unregulated DC voltage;
controlling conversion of the unregulated DC voltage to the regulated DC high voltage responsive to a DC high voltage reference input;
converting the DC high voltage to a high-frequency AC voltage;
controlling conversion of the DC high voltage to the high-frequency AC vol

Assignees

• Tran Ken
• Tian Feng
• Chen Xing
• Lee Franklin
• Mks Instr Inc

Inventors

• Tran Ken
• Tian Feng
• Chen Xing
• Lee Franklin

Classifications

• C01B2201/90

  Control of the process · CPC title

• H02M1/32

  Means for protecting converters other than automatic disconnection · CPC title

• C01B13/11

  by electric discharge · CPC title

• H02M1/36

  Means for starting or stopping converters · CPC title

• C01B13/115 Primary

  characterised by the electrical circuits producing the electrical discharge · CPC title