Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J19/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
  • B01J19/08—Processes employing the direct application of electric or wave energy, or particle radiation; Apparatus therefor
  • B01J19/087—Processes employing the direct application of electric or wave energy, or particle radiation; Apparatus therefor employing electric or magnetic energy
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
  • C01B13/00—Oxygen; Ozone; Oxides or hydroxides in general
  • C01B13/10—Preparation of ozone
  • C01B13/11—Preparation of ozone by electric discharge
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
  • C01B13/00—Oxygen; Ozone; Oxides or hydroxides in general
  • C01B13/10—Preparation of ozone
  • C01B13/11—Preparation of ozone by electric discharge
  • C01B13/115—Preparation of ozone by electric discharge characterised by the electrical circuits producing the electrical discharge
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
  • H02M5/00—Conversion of AC power input into AC power output, e.g. for change of voltage, for change of frequency, for change of number of phases
  • H02M5/40—Conversion of AC power input into AC power output, e.g. for change of voltage, for change of frequency, for change of number of phases with intermediate conversion into DC
  • H02M5/42—Conversion of AC power input into AC power output, e.g. for change of voltage, for change of frequency, for change of number of phases with intermediate conversion into DC by static converters
  • H02M5/44—Conversion of AC power input into AC power output, e.g. for change of voltage, for change of frequency, for change of number of phases with intermediate conversion into DC by static converters using discharge tubes or semiconductor devices to convert the intermediate DC into AC
  • H02M5/453—Conversion of AC power input into AC power output, e.g. for change of voltage, for change of frequency, for change of number of phases with intermediate conversion into DC by static converters using discharge tubes or semiconductor devices to convert the intermediate DC into AC using devices of a triode or transistor type requiring continuous application of a control signal
  • H02M5/458—Conversion of AC power input into AC power output, e.g. for change of voltage, for change of frequency, for change of number of phases with intermediate conversion into DC by static converters using discharge tubes or semiconductor devices to convert the intermediate DC into AC using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only
  • H02M5/4585—Conversion of AC power input into AC power output, e.g. for change of voltage, for change of frequency, for change of number of phases with intermediate conversion into DC by static converters using discharge tubes or semiconductor devices to convert the intermediate DC into AC using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only having a rectifier with controlled elements
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
  • H02M7/00—Conversion of AC power input into DC power output; Conversion of DC power input into AC power output
  • H02M7/42—Conversion of DC power input into AC power output without possibility of reversal
  • H02M7/44—Conversion of DC power input into AC power output without possibility of reversal by static converters
  • H02M7/48—Conversion of DC power input into AC power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
  • H02M7/53—Conversion of DC power input into AC power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal
  • H02M7/537—Conversion of DC power input into AC power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only, e.g. single switched pulse inverters
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
  • Y02B70/00—Technologies for an efficient end-user side electric power management and consumption
  • Y02B70/10—Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
  • Y02P20/00—Technologies relating to chemical industry
  • Y02P20/10—Process efficiency

Definitions

• Ozone is useful for numerous applications that require a high level of oxidation.
• ozone is useful for disinfection of drinking water and has been used for water treatment since the early 1900s. More recently, ozone has been used for semiconductor device processing.
• One application for ozone in semiconductor device processing is forming insulating layers on semiconductor wafers by growing insulating films or by oxidizing thin films on the wafer. For example, high deposition rate chemical vapor deposition of high quality SiO 2 can be accomplished by using a TEOS/ozone process.
• Ozone is particularly useful for removing hydrocarbons from the surface of semiconductor wafers or from processing chambers.
• Using ozone for cleaning is advantageous because it avoids the use of dangerous chemicals which require costly disposal.
• ozone does not present a toxic waste disposal problem because ozone decays to oxygen without residues.
• Ozone can be generated from oxygen according to a so-called "silent discharge principle.” For instance, ozone can be generated by exposing high purity oxygen to an electrical discharge or an electrical flux. The discharge or flux excites the oxygen molecules, breaking them into their atomic state. The atoms then recombine into a mixture of ozone (O 3 ) and oxygen (O 2 ).
• Ozone O 3
• O 3 Ozone
• the electrical discharge or electrical flux needed for ozone generation is produced by applying a high voltage AC power across opposing plates of the ozone cell.
• the high voltage AC power is produced from transformer-based power oscillators.
• Disadvantages of a transformer-based power supply typically include high cost, limited reliability, and limited range of operation.
• the high cost is typically due to the high-voltage transformer with multiple windings and special potting requirements for cooling and insulation.
• Limited reliability is typically due to the topology of the self-oscillator, high voltage corona caused by the dependence of the potting quality, and use of single source unique parts.
• Limited range of operation with respect to the regulated output voltage is typically due to the self-oscillator topology and use of transformer feedback for the transistor's gate drive.
• the present invention is directed to a method and apparatus for supplying power using a power supply including transformer-less high voltage power oscillators for ozone generation. Embodiments of the present invention can reduce cost, increase reliability and operation range of ozone generators.
• One embodiment includes a power supply having a power source and a resonant circuit coupled to the power source, the power source providing a first AC voltage to the resonant circuit, the resonant circuit providing a second AC voltage for use by an ozone generating unit, the second AC voltage being greater than the first AC voltage.
• the resonant circuit can apply a substantially resonant voltage to the ozone generating unit in response to the first AC voltage having a frequency substantially close to the resonant frequency of the resonant circuit.
• the resonant circuit can be a series resonant circuit including a resonant inductor coupled in series with a resonant capacitor.
• the resonant capacitor can be an individual capacitor, a natural capacitance of the ozone generating unit, or a combination of both an individual capacitor and natural capacitance of the ozone generating unit.
• the resonant circuit has a q-factor greater than or equal to 10.
• the resonant circuit can be a parallel resonant circuit including a resonant inductor coupled in parallel with a resonant capacitor.
• the resonant capacitor can be an individual capacitor, a natural capacitance of the ozone generating unit, or a combination of both an individual capacitor and natural capacitance of the ozone generating unit.
• the power source can be a half bridge inverter, a full bridge inverter, and/or a switching power source.
• the switching elements can be MOSFETs, BJTs, IGBTs, and/or any other type of switching elements.
• the power supply can further include a controller providing signals to the power source that cause the power source to modulate the first AC voltage, resulting in the second AC voltage having a desired voltage magnitude.
• the first AC voltage can be modulated using pulse width modulation and/or frequency modulation.
• the controller can provide signals to the power source that allows the resonant circuit to operate at its maximum operating resonant frequency.
• the controller can tune to the maximum operating frequency of the resonant circuit by comparing a sensed input DC current to a set point input current.
• the controller can control a resonant voltage of the ozone generating unit during self-tuning to the maximum operating frequency of the resonant circuit by comparing a sensed resonant current to a set point resonant current.
• Embodiments of the invention also include a power supply for ozone generation. Other embodiments of the invention may be applied for supplying power for generation of any reactive gases.
• Advantages of the embodiments of the invention include reduced cost and increased reliability and operation range of ozone generators by eliminating the need for a transformer.
• a high Q resonant circuit (Q ⁇ IO typically for an ozone generator) instead of a transformer implies that the circuit resonant frequency peak is narrow. Since its center frequency depends on circuit elements with tolerances often wider than the resonance peak width, control of such a circuit can be a problem.
• a circuit to control high Q resonant circuits allows realization of the advantages above in both ozone generators and in resonant power supplies for other applications.
• FIG. 1 is a diagram illustrating a typical ozone generator
• FIG. 2 is a diagram that illustrates a transformer-based power supply used in an ozone generator according to the prior art
• FIG. 3 is a diagram illustrating a power supply having a transformer-less power oscillator for ozone generation in a single ozone cell according to one embodiment
• FIG. 4 is a diagram illustrating a power supply having a transformer-less power oscillator for ozone generation in a single ozone cell according to a particular embodiment
• FIG. 5 A shows a detailed schematic of one embodiment of a frequency modulation controller
• FIG. 5B shows a detailed schematic of one embodiment of a pulse- width modulation controller
• FIG. 6 shows a graph showing the relationship between set point power and resonant frequency
• FIG. 7 is a diagram illustrating a power supply having multiple transformer-less power oscillators for ozone generation across multiple ozone cells according to one embodiment
• FIGS. 8A and 8B are diagrams illustrating a power supply having a transformer-less power oscillator for ozone generation in a single ozone cell according to other particular embodiments.
• FIG. 1 is a diagram illustrating a typical ozone generator 100.
• the ozone generator 100 includes a bank of ozone generating units, referred to herein as ozone cells 11 Oa...11 On.
• Oxygen (O 2 ) is supplied to each ozone cell 110 through an oxygen inlet 120 for conversion into a mixture of ozone (O 3 ) and oxygen (O 2 ).
• the resulting ozone mixture flows out of the ozone generator 100 through an ozone outlet 130.
• Components of the ozone cell 110 typically include opposing electrode plates (not shown) and a dielectric barrier (not shown).
• the dielectric barrier is positioned against one of the electrode plates, forming a channel between the dielectric barrier and the opposing electrode plate.
• oxygen (O 2 ) passing through the channel is acted upon by an electrical discharge causing the dissolution and recombination of the oxygen atoms into ozone molecules.
• high voltage AC power is applied across the opposing electrode plates of each ozone cell 110.
• the high voltage AC power is provided by a bank of power oscillators 140a...14On with each oscillator 140 supplying power to a respective ozone cell 110.
• the power oscillators 140 are coupled to a common DC power supply 150 that can convert single-phase or three-phase AC line voltage 152 into a regulated DC voltage (Vdc).
• Vdc regulated DC voltage
• Each oscillator 140 converts the regulated DC voltage (Vdc) into high voltage AC power that is supplied to a corresponding/respective ozone cell 110, resulting in the electrical discharge or electrical flux needed for ozone generation.
• An exemplary embodiment of the ozone cell 110 can be found in U.S. Patent 5,932, 180, the entire contents of which are incorporated herein by reference.
• FIG. 2 is a diagram that illustrates a transformer-based power supply 200 used in an ozone generator according to the prior art.
• the illustrated power supply 200 consists of a DC power supply 210 and two additional stages: (1) a buck converter 220 for regulation of output power and (2) a self oscillating push-pull converter 230 that includes a transformer 232 to generate the high voltage AC power across the ozone cell 110.
• FIG. 3 is a diagram illustrating a power supply 300 having a transformer-less power oscillator 310 for ozone generation in a single ozone cell 110 according to one embodiment.
• the power oscillator 310 includes a power source 320. coupled to a resonant circuit 330.
• the resonant circuit 330 is coupled, in turn, to the ozone cell 110.
• the power source 320 can be a switching power source.
• the power source 320 converts a regulated DC voltage (Vdc) from a DC voltage source 210 into a first AC voltage that is supplied to the resonant circuit 330.
• the first AC voltage from the power source 320 has a frequency substantially close to the resonant frequency of the resonant circuit 330.
• the resonant circuit 330 applies a substantially resonant second AC voltage to the ozone cell 110 causing an electrical discharge or flux within the ozone cell 110.
• the power supply 300 is able to provide high voltage AC power (a second AC voltage) needed for ozone generation in the ozone cell 110 without the use of a transformer.
• a controller 340 provides control signals to the power source 320 that cause the power source 320 to modulate the frequency and/or duty cycle of the first AC voltage resulting in the resonant circuit 330 providing a substantially second AC resonant voltage having a desired magnitude to the ozone cell 110.
• the second resonant AC voltage can be 4.5 kVpk at 30 kHz.
• the controller 340 compares a reference current REF with a sensed input current at the power source 320 and sends control signals (gate control signals) to the power source 320 to make adjustments to the operating frequency or duty cycle of the power source 320 to obtain the desired magnitude.
• the first AC voltage can be modulated by the controller 340 using pulse-width modulation and/or frequency modulation.
• the controller 340 can be configured to sense voltage, current, or a combination thereof to determine and control the desired resonant voltage.
• FIG. 4 is a diagram illustrating a power supply 400 having a transformer-less power oscillator 404 for ozone generation in a single ozone cell 110 according to a particular embodiment.
• the resonant circuit 420 is a series resonant circuit including a resonant inductor 422 coupled in series with a resonant capacitor 424
• the ozone cell 110 is coupled in parallel with the resonant capacitor 424.
• the resonant capacitor 424 can be a separate individual capacitor, the natural capacitance of the ozone cell 110, or a combination thereof.
• the power source 410 is a half bridge inverter including two switching elements 412a, 412b connected in series.
• the switching elements 412a, 412b can be MOSFETs, BJTs, IGBTs and/or any other type switching elements known in the art.
• the electrical connection between the switching elements 412a, 412b is connected to the resonant circuit 420.
• the power source 410 can also be a full bridge inverter as shown in FIGS. 8 A and 8B.
• a DC power supply 210 supplies a regulated DC voltage (Vdc) to the power source/half bridge inverter 410.
• Control signals from the controller 340 are provided to a gate driver 540 (FIGS. 5 A and 5B) that causes the switches 412a, 412b to turn on and off resulting in the half bridge inverter 410 supplying the first AC voltage having a frequency substantially close to the resonant frequency of the series resonant circuit 420.
• the first AC voltage applied to the resonant circuit 420 can be square wave pulses with a controlled duty cycle.
• the control signals can also change the duty cycle of the half bridge inverter 410 to alter the magnitude of the second resonant AC voltage applied to the ozone cell 110.
• the series resonant circuit 420 In response to receiving the first AC voltage from the half bridge inverter 410, the series resonant circuit 420 provides a resonant or substantially second resonant AC voltage across the ozone cell 110 such that an electrical discharge or flux is provided within the cell to effect conversion of oxygen (O 2 ) to ozone (O 3 ). Particularly, the resonant circuit 420 converts the applied square wave pulses with a controlled duty cycle to a high voltage sine wave of controlled amplitude. According to one embodiment, the frequency and magnitude of the second resonant AC voltage is approximately 4.5 kVpk at 30 kHz.
• the ratio of ozone (O 3 ) to oxygen (O 2 ) depends on the amount of power supplied to the ozone cells 110.
• the power applied to the ozone cell 110 increases in proportion to the voltage applied to the ozone cell 110 and is regulated by the controller 340 in accordance with the reference signal REF as described above.
• the controller 340 can alter the concentration of ozone.
• the resonant frequency changes with even a small variation in inductance and capacitance.
• the resonant circuit 420 should have a high Q factor (greater than or equal to 10) to eliminate the need for transformer. Therefore, the controller 340 should be independent of the resonant component variation.
• FIGS. 5A and 5B show a detailed schematic of embodiments of a controller 500.
• the major components of the controller 500 include a pulse-width modulated integrated circuit (PWM IC) 510, a first operational/error amplifier 520, a second operational/error amplifier 530, a gate driver circuit 540, a first resistor 550, and a second resistor 560.
• PWM IC pulse-width modulated integrated circuit
• FIG. 5 A shows one embodiment of a frequency modulated controller 500'.
• the operational amplifier/error amplifier 520 compares the sensed DC input current 522 with the set point DC current 524.
• the resistors 550, 560 control the frequency of the PWM IC 510.
• the output of the error amplifier 520 controls the current flowing through the resistor 550 by pulling it up or down and thus controls the frequency of the controller 510.
• the controller 500' includes an auto tuning circuit that ensures the initial frequency generated by the error amplifier 520 is the maximum operating frequency of the resonant circuit 420 (FIG. 4).
• the tuning circuit includes a resistor 526, a capacitor 528, and a small offset voltage at the sensed input of the error amplifier 520.
• the DC current set point 524 slowly increases from zero to its set point through a delay created by the resistor 526 and capacitor 528.
• the offset voltage at the error amplifier 520 ensures that the frequency generated by the error amplifier is the maximum operating frequency of the circuit.
• the maximum resonant frequency is determined by considering the maximum tolerance on the resonant circuit elements and the capacity of the switching devices.
• FIG. 6 shows a graph showing the relationship between the set point power and the resonant frequency.
• the pulse-width modulation frequency starts reducing from its maximum value toward maximum power. That is, pulse- width modulation frequency walks over the resonant curve to achieve the maximum power.
• the controller 500' includes a second operational amplifier/error amplifier 530.
• the error amplifier 530 controls the resonant voltage of the ozone cell 110 by comparing the sensed resonant current 532 to the set point resonant current 534.
• FIG. 5B shows one embodiment of a pulse- width modulation controller 500".
• the operation of the pulse-width modulation controller 500" is similar to the operation with respect to the frequency modulated controller 500' as described above.
• FIG. 7 is a diagram illustrating a power supply 600 having multiple transformer-less power oscillators 404a...404n for ozone generation across multiple ozone cells 110a...11On according to one embodiment.
• the regulated DC voltage (Vdc) (e.g. approximately 400V) is provided by a known full bridge high frequency converter 610.
• the high frequency converter 610 includes a rectifier stage 612, a full bridge switching stage 614, a transformer stage 616, and a filter stage 618.
• Other circuits known to those skilled in the art can also be implemented to provide the regulated DC voltage.
• the power oscillators e.g. approximately 400V
• Each oscillator 404 includes a power source 410 coupled to a resonant circuit 420.
• the power sources 410 are half bridge inverters implemented using MOSFET switching devices 412a, 412b. Other switching devices known to those skilled in the art may also be utilized. Also, mixed implementations of half-bridge oscillators, full-bridge oscillators, and other known devices may be employed. The operation of the illustrated embodiment is similar to the operation described with respect to FIGS. 1 and 4.
• FIGS. 8A and 8B are diagrams illustrating a power supply 700 having a transformer-less power oscillator for ozone generation in a single ozone cell 110 according to other particular embodiments.
• the power source 710 is implemented as a full bridge converter with four switching elements 712a, 712b, 712c, 712d coupled as shown.
• a voltage supply 210 supplies regulated DC voltage (Vdc) to the full bridge converter 710.
• Vdc regulated DC voltage
• the full bridge converter 710 is coupled to a series resonant circuit 720 having a resonant inductor 722 coupled in series with a resonant capacitor 724.
• the resonant circuit 720 is coupled, in turn, to an ozone cell 110 as shown.
• a current supply 730 supplies a regulated DC current (Idc) to the full bridge converter 710.
• the full bridge converter 710 is coupled to a parallel resonant circuit 740 having a resonant inductor 742 coupled in parallel to a resonant capacitor 744.
• the resonant circuit 740 is coupled, in turn, to an ozone cell 110 as shown.
• the resonant capacitor can be a separate individual capacitor or can be the natural capacitance of the ozone cell 110 or combination of both an individual capacitor and natural capacitance of the cell.

Landscapes

• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Engineering & Computer Science (AREA)
• Power Engineering (AREA)
• Inorganic Chemistry (AREA)
• General Health & Medical Sciences (AREA)
• Health & Medical Sciences (AREA)
• Toxicology (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Oxygen, Ozone, And Oxides In General (AREA)
• Inverter Devices (AREA)
• Dc-Dc Converters (AREA)
• Generation Of Surge Voltage And Current (AREA)

Priority Applications (5)

Applications Claiming Priority (2)

Publications (1)

Family

ID=37719271

Family Applications (1)

Country Status (7)

Cited By (6)

Families Citing this family (16)

Family Cites Families (20)

• 2006
  • 2006-08-14 EP EP12174905.5A patent/EP2523336B1/en not_active Not-in-force
  • 2006-08-14 US US11/503,662 patent/US8226900B2/en active Active
  • 2006-08-14 CN CN2006800346516A patent/CN101288219B/zh active Active
  • 2006-08-14 KR KR1020087004458A patent/KR101323046B1/ko active Active
  • 2006-08-14 EP EP06836103.9A patent/EP1929615B1/en not_active Not-in-force
  • 2006-08-14 JP JP2008527033A patent/JP5355085B2/ja active Active
  • 2006-08-14 CN CN201210137285.4A patent/CN102664536B/zh active Active
  • 2006-08-14 WO PCT/US2006/031664 patent/WO2007035216A1/en not_active Ceased
  • 2006-08-16 TW TW095130091A patent/TWI393338B/zh active
• 2012
  • 2012-06-20 US US13/528,580 patent/US8641978B2/en active Active
• 2013
  • 2013-02-01 JP JP2013018441A patent/JP2013085475A/ja active Pending

Non-Patent Citations (4)

Also Published As

Similar Documents

Legal Events