CA2235256A1 - Method and apparatus for utilizing dielectric breakdown for indirect measurement purposes - Google Patents
Method and apparatus for utilizing dielectric breakdown for indirect measurement purposes Download PDFInfo
- Publication number
- CA2235256A1 CA2235256A1 CA 2235256 CA2235256A CA2235256A1 CA 2235256 A1 CA2235256 A1 CA 2235256A1 CA 2235256 CA2235256 CA 2235256 CA 2235256 A CA2235256 A CA 2235256A CA 2235256 A1 CA2235256 A1 CA 2235256A1
- Authority
- CA
- Canada
- Prior art keywords
- voltage
- pulses
- sensed
- signal
- converting
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/12—Testing dielectric strength or breakdown voltage ; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing
- G01R31/1227—Testing dielectric strength or breakdown voltage ; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing of components, parts or materials
- G01R31/1263—Testing dielectric strength or breakdown voltage ; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing of components, parts or materials of solid or fluid materials, e.g. insulation films, bulk material; of semiconductors or LV electronic components or parts; of cable, line or wire insulation
- G01R31/1281—Testing dielectric strength or breakdown voltage ; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing of components, parts or materials of solid or fluid materials, e.g. insulation films, bulk material; of semiconductors or LV electronic components or parts; of cable, line or wire insulation of liquids or gases
-
- 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
Abstract
A device for measuring the breakdown of a dielectric in the presence of high voltage, for measuring e.g. ozone production in an ozone generator using the corona discharge principle. Corona discharge pulses in an ozone generator are capacitively sensed. Low frequencies are filtered out of the sensed signal.
Electrical noise from the transformer circuitry is isolated by an optical coupler with an isolated direct current power supply. The filtered signal is then amplified and transformed to a DC voltage. After calibration to the actual ozone being produced, the DC output can be directly related to the ozone produced in the generator and used to display and/or control the ozone production.
Electrical noise from the transformer circuitry is isolated by an optical coupler with an isolated direct current power supply. The filtered signal is then amplified and transformed to a DC voltage. After calibration to the actual ozone being produced, the DC output can be directly related to the ozone produced in the generator and used to display and/or control the ozone production.
Description
CA 0223~2~6 1998-04-17 METHOD AND APPARATUS FOR UTILIZING
DIELECTRIC BREAKDOWN FOR INDIRECT MEASUREMENT PURPOSES
FIFI n OF THE INVENTION
The present invention relates to apparatus and methods which utilize the breakdown of a dielectric in the presence of high voltage for indirect measurement purposes, and more specifically relates to apparatus and methods for indirectly measuring the production of ozone by an ozone generator using the corona discharge principle.
In many application areas, it is desirable to evaluate the breakdown of a dielectric in order to effectively measure the products that are created by the breakdown. For1Q example, the breakdown of a gas dielectric in the presence of high voltage will create products of that breakdown that are chemically related to the original dielectric. An example is the production of ozone (03) by the high voltage breakdown of oxygen (~2) in a typical corona discharge ozone generator.
In many application areas of ozone, it is imperative that ozone concentration and production be accurately measured. Photospectrometers, using a direct ultraviolet absorbance method, are the most common means of measuring the concentration of ozone. Other instruments that are used include: calorimetric instruments using anumber of different chemical dyes in water, instruments for measuring changes indielectric constant due to ozone, CO2 lasers, luminescent methods, coulombometric gas analysers, polarographic instruments, calorimetric instruments, and amperometricinstruments. Instruments used for measuring ozone in most applications must be economical and must be able to continuously measure the absolute concentration values of ozone without significant drift over time. Consequently, the above-listed instruments suffer from a number of disadvantages.
One of the disadvantages of the above-listed instruments is that they are not feasible in smaller ozone generator installations due to economic considerations. Also, suchprevious instruments, including photospectrometers, experience drift in their outputs over time in comparison with a reference instrument. Similarly, such previous CA 02235256 l998-04-l7 instruments are $ensitive to physically ~ .. cOn-liliV~S. F~ ....ole, the r~lativoly heavy weight and large physical size of most of such previous instruments ~re a problc.,) during i~ lt lion where spnce snd pG,I.~Lilil~ are i...,~oil~.nt. Add;~iG,.aliy, it is common in such ozone s6nsGrs to require a cGIllplicdled ,ul_rII~ce in order to convert the cl,cr"i~al, optical, heat, etc. inputs to a linear clLcL,ical output signal.
Accold;,-gly, it would be desirable to provide a means for measuring ozone production in an ozone generator using the corona discharge principle to avoid the aforesaid difficulties.
SUMMARY OF THE INVENTION
In accordance with the present invention the breakdown of a dietectric in the presence of high voltage is utilized to measure parameters of inlerest. The dieiectric rnay be a gas, a liquid or a solid. The purpose of the measurement can be to measure the breakdown products of the dielectric, or to messure the physical or chemical properties of tl~e diele~.l,ic. In El p~ .Ied aspect of the invention. the measurement of the dielectric breakdown provides a means to measure the production of ozone in an ozone generator using the corona discharge ,r,,i"-i~ le.
Pursuant to the invention corona electrical discharge puises from a winding in a voltage Ll.,.l~iur",er providing electrical charging pulses to a high voltage discharge apparatus are sensed, and an electrical signal is generated in accordance with the sensed pulses.
The electric signal is converted into a direct current ~D.C.~ voltage the level of which is a function of the frequency of occurrence and magnitude of said sensed electrical discharge pulses Dnd thereby 8 measure of disle_L,ic breakdown product production in said high voltsge discharge apparatus. The D.C. voltage level may be caliLr~Led against measured di~lecLdc breP'~~o~ n product production in the spparatus, to enable measurement of the actual dielccllic breakdown product production from the measured D.C. voltage level.
The prcsenl invention can be realized with a dielectric breakdown circuit comprising 8 capacitive transducer, a first high pass filter, an optical coupler powered by an isolated direct current power supply, a two-stage radio frequency (RFI c..llpl;~ie" a second high CA 0223~2~6 1998-04-17 WO 97/14973 PCT/lB96/01122 pass filter, an s.ll~liri~/diode pump, a linearizer, a low pass filter and a scalin~ r;...,~Jl;rier.
The capacitive transducer is co~ to the sccond~r~ wil~d;..~ of a high voltage transformer, which is used to provide high voltage pulses to 8 corona discharge ozone ~~e.~ or. The cApacitive transducer thus capacitively senses individual corona S discharge pulses that are i.. ,posed on the voltage signal of the secondary winding of the high voltage ~a"sru,."er. Lower frequencies, such as the high voltage drive frequency, are filtered out of the capacitive transducer signal in the first high pass filter. The optical coupler electrically isolates the processing circuitry from the high voltage transformer coupling. An isolated direct current power supply separates the power source of the optical coupler from the power source used for the processing circuitry, thereby reducing electrical noise induced by the transformer circuitry~ The capacitive transducer signal is then amplified in the two-stage RF amplifier. Low frequencies sre further reduce~ in the second high pass filter. The direct current voltage is amplified and voltage ripple is reduced in the a...~ ier/diode pump. The linearizer provides a 1~ voltage-dependent adjustment to the gain of the amplifier/diode pump to create linear voltsge output values. Any remaining voltage ripple in the direct current voltage is re~ ced in the low pass filter, then F.n~.liricd in the scaling amplifier for input to a analog-to-digital converter snd then to a ..-iclol,rc,cessor. A photospectrometer or other device is used to calibrate the direct current voltage values in relation to the actual level of ozone being produced. The direct current voltage is then directly related to the formation of dielectric breakdown products in the presence of high voltage.
In summary, in the prere--ed embodiment, corona discharge pulses in an ozone generator are capacitively sensed. First, low frequencies are filtered out of the sensed signal. The sensed signal is then elecl~ic&:ly isolated by an optical coupler, amplified, rectified, linearized, filtered and an., I;ried aç~ain into a ripple-free direct current vottage signal. After caliLr"Lion to the actual ozone being produced, this direct current voltage signal is directly related to ozone production in the ozone generator.
From the above descriptive summary it is apparent how the present invention over~u, ~ .es the sho. Lcul . .ings of the above-mentioned prior art.
ACCGI~jll91Y, an object of the ,u.ese.-L invention is to provide cost effective apparatus and rnethods to measure the breakdown of a dielectric in the pre~ence of high voltage, CA 0223~2~6 1998-04-17 Wo 97/14973 PCT/IB96/011Z2 thereby providing a very cost effective measuring and signal condilion;--g circuit.
Another object of the present invention is to provide apparatus and method for measuring the breakdown products that are created by the breakdown of the dielectric.
Another object of the prese"~ invention is to provide apparatus and method for measuring ozone production in an ozone generator using the corona discharge principle.
Another object of the present invention is to provide an instrument for the aforementioned purposes, which is comprised completely of solid state elsctronics and is therefore very rugged.
Another object of the present invention is tO provide ~or the aforementioned purposes a very light weight and compact instrument, which is suitable for installations where space snd portability is important.
Anoth~r object of the present invention is to provide for the aforementioned purposes a completely solid state instrument with a linear output signal.
Other objects and advantages of the present invention will become apparent to those skilled in the art upon reading the following detailed description and claims inconjunction with the accor.,panying drawings which are appended hereto.
BRIEF DF.~CRIPTION OF THF DRAWINt;S
In order to facilitate a fuller understanding of the present invention reference may now be made to the appended drawings. The drawings should not be construed as limiting O the present invention, but are intended to be exer"pla, y only.
Fi~ure 1 is a schematic block diagram of a dielectric breakdown measL-,ernent circuit according to the present invention which may be used for measurement of ozone production; and Fi~ure 2 is a ;.CI~ LiC block d;n~3m of a hi~h voltage l.a,.aru,.,.er with a capscitive transducer affixed thereto accor~l;..g to the plascnL invention.
DETAII Fn DESCRIPTION OF TH} pREFFRRFn FMBODIMF~IT
Referring to Figure 1, there is shown a schematic block diagram of a dielectric breakdown measurement circuit 10 accorciir~ç3 to the present invention. The dielectric breakdown measu.~,."enl circuit 10 comprises a capacilive transducer assembly 12, a first high pass filter 14, an optical coupler 16 powered by an isolated direct current power supply 18, a two-stage rsdio frequency (RF) amplifier 20, a second high pass filter 22, an amplifierldiode pump 24, a linearizer 26, a low pass filter 28 and a scaling amplifier 30. The output from ampiifier 30 may be provided to an analog-to-digital (A/D) - converter 32, which in turn provides a signal to a microprocessor 34.
The capacitive transducer asse...bly 12 is a capacitive coupling to the secondary winding of a high voltage L,~,nsrGr."er, which is used to provide high voltage pulses to a corona discharge ozone generator. Such a corona discharge ozone generator is ~;cclosed in U.S. Patent No. 5,094,882, entitled Ozone Generator, which issued March 10, 1~92, and such a high voltage Lrar-stGr",er is disclosed in U.S. Patent No.
~,443,800, ellLiLled Pulse Train Generating Circuit for Control of an Ozone Generating Means, which issued August 22, 1g95. The disclosures of these patents, which have a common inventor with the ~lese.lL invention, are hereby incorporated by reiere"ce herein.
The c~pacitive transducer assembly 12 capacitively senses individual corona discharge pulses tllat are imposed on the voltage signal of the secondary winding of the high voltage L~a~arOIIller. Lower frequencies, such as the high voltage drive frequency, are filtered out of the transducer signal in the first high pass filter 14. The optical coupler allows the p~ssage of the transducer signal, while isolating the electrical noise presen~
in the high voltage L~..na~un,~er circuitry The isolated direct current power supply 18 aids in ~cl, _.ri"g this elccl~ical isolation. The optical coupler 16 may be of a conventional type, based ê.9. upon an LED light source and a spaced pboLGd;ode sensor. The transducer signal is then amplified in the two-stage RF amplifier 20. Low CA 0223~2~6 1998 - 04 -17 WO 97/14973 PCTtIB96/01122 fr~quencies E~re further r~duced in the second hi~h pass filter 22. Th9 voltage pulses are .A.I~pliried and mod~lated by a diode pump circuit in the amplifierldiode pump 24, which provides a measure of the ampiitude and frequency of the pulses. The linearizer 26 provides a voltage dependent adjustment to the gain of the amplifier/diode pump 24 to create linear voltage output values. Any remaining voltage ripple in the direct current voltage is reduced in the low pass filter 28. The direct current voltage is amplified in the scaling amplifier 30. After calibration to the actual dielectric product, e.g., ozone, being produced, the direct current voltage is now directly related to the breakdown of the dielectric in the presence of high voltage, and can then be converted into digital form by the A/D converter 32. The microprocessor 34 can then process the diç~ital data so as to provide a display of the breakdown of the dielectric, which in the present embodiment is the amount of ozone being produced by the ozone generator. The ,.icroprocessor 34 can then control the rate of dielectric product, e.g. ozone, production in a high voltage ozone generator.
The direct current voltage levels provided from scaling amplifier 30 are calil~.~ted to the actual levels of ozone being produced as measured by a convenLiGnal spectrophotometer. This is effected by e:,Lal~lishi.~g a series of points relating measured voltage levels to measured ozone concenL~aLions. The established relationship thereb enables direct calibration of readout voltage levels in terms of ozone concentration.
It should be noted that the sequence of the signal conditioning described above may be varied and, in fact, some of the above-descnLed signal co"diLioniog functions may be Ol l li LLed .
The overall function of the transducer signal co:.diLionillg in the dielectric breakdown measuring circuit 10 is to provide a means for converting sensed corona discharge pulses into a direct current voltage which is represenLaLive of the frequency and magnitude of occurrence of these corona discharge pulses. The generation of the corona discharge pulses is relatively uniform if the physical dimensions ~i.e. gap size) of the ozone generator are held fixed and the composition and flow rate of gases flowing through the ozone generator are properly regulated. However, the actual amount of ozone production in the ozone gene~aLur is dependent on the frequency and magnitude of the corona disc~,a,ye pulses. The present invention is therefore directed toward CA 0223~2~6 1998-04-17 ~ena;,.S~ corona discharge pulses and then converting the sensed corona Jiscl.alçlc pulses into a direct current voltaç~e hsving a voltage level that is ~:pras&.,L~ e of the frequency and ",a~uil.lde of occurrence of the sensed corona discharge pulses snd thereby directly related to the ozone production in the ozone generator.
S~ It should be noted that the capacitive transducer assembly 12, which consists of an aluminum plate, need not be actually affixed to the insulating material surrounding the secondary winding in the high voltage transformer, but must merely be in close proximity to the secondary winding in the high voltage transformer so as to sense the individual corona discharge pulses.
Referring to Figure 2, there is shown a schematic block dlagram revealing a typical physical relationship between a high voltage transformer 40 and a corona discharge pulse capacitive transducer 42 according tO the present invention. The high voltage L,ansrG",-er 40 co",prises a primary winding tnot shown) and a high voltage secondary winding 44.
-In this par~icular embodiment, the capacitive transducer 42 comprises an aluminum plste, approximately 10 x 10 mm square, which is fixed to the insulating material surrounding the high voltage secondary winding 44. The high voltage secondary winding 44 provides high voltage pulses to an ozone generator ~not shown). These high voltage pulses produce corona discharges in the ozone generator. The capacitive transducer 42 capacitively senses these corona discharges as pulses of electrical charge from the high voltage secondary winding 44. These sensed corona discharç~e pulses may then be signal conditioned by the dielectric breakdown measurement circuit accGrdi, ,9 to the present invention.
With the present invention now fully described, it can thus be seen that the objects set 2~ forth above are efficiently attained and, since certain changes may be made in the above-described embodiments without departing from the scope of the invention, it is intended that all matter contained in the above desc.i~Lion or shown in the acco...p~""~ing drawings shall be i"~er~e~ed as illustrative and not in a limiting sense.
DIELECTRIC BREAKDOWN FOR INDIRECT MEASUREMENT PURPOSES
FIFI n OF THE INVENTION
The present invention relates to apparatus and methods which utilize the breakdown of a dielectric in the presence of high voltage for indirect measurement purposes, and more specifically relates to apparatus and methods for indirectly measuring the production of ozone by an ozone generator using the corona discharge principle.
In many application areas, it is desirable to evaluate the breakdown of a dielectric in order to effectively measure the products that are created by the breakdown. For1Q example, the breakdown of a gas dielectric in the presence of high voltage will create products of that breakdown that are chemically related to the original dielectric. An example is the production of ozone (03) by the high voltage breakdown of oxygen (~2) in a typical corona discharge ozone generator.
In many application areas of ozone, it is imperative that ozone concentration and production be accurately measured. Photospectrometers, using a direct ultraviolet absorbance method, are the most common means of measuring the concentration of ozone. Other instruments that are used include: calorimetric instruments using anumber of different chemical dyes in water, instruments for measuring changes indielectric constant due to ozone, CO2 lasers, luminescent methods, coulombometric gas analysers, polarographic instruments, calorimetric instruments, and amperometricinstruments. Instruments used for measuring ozone in most applications must be economical and must be able to continuously measure the absolute concentration values of ozone without significant drift over time. Consequently, the above-listed instruments suffer from a number of disadvantages.
One of the disadvantages of the above-listed instruments is that they are not feasible in smaller ozone generator installations due to economic considerations. Also, suchprevious instruments, including photospectrometers, experience drift in their outputs over time in comparison with a reference instrument. Similarly, such previous CA 02235256 l998-04-l7 instruments are $ensitive to physically ~ .. cOn-liliV~S. F~ ....ole, the r~lativoly heavy weight and large physical size of most of such previous instruments ~re a problc.,) during i~ lt lion where spnce snd pG,I.~Lilil~ are i...,~oil~.nt. Add;~iG,.aliy, it is common in such ozone s6nsGrs to require a cGIllplicdled ,ul_rII~ce in order to convert the cl,cr"i~al, optical, heat, etc. inputs to a linear clLcL,ical output signal.
Accold;,-gly, it would be desirable to provide a means for measuring ozone production in an ozone generator using the corona discharge principle to avoid the aforesaid difficulties.
SUMMARY OF THE INVENTION
In accordance with the present invention the breakdown of a dietectric in the presence of high voltage is utilized to measure parameters of inlerest. The dieiectric rnay be a gas, a liquid or a solid. The purpose of the measurement can be to measure the breakdown products of the dielectric, or to messure the physical or chemical properties of tl~e diele~.l,ic. In El p~ .Ied aspect of the invention. the measurement of the dielectric breakdown provides a means to measure the production of ozone in an ozone generator using the corona discharge ,r,,i"-i~ le.
Pursuant to the invention corona electrical discharge puises from a winding in a voltage Ll.,.l~iur",er providing electrical charging pulses to a high voltage discharge apparatus are sensed, and an electrical signal is generated in accordance with the sensed pulses.
The electric signal is converted into a direct current ~D.C.~ voltage the level of which is a function of the frequency of occurrence and magnitude of said sensed electrical discharge pulses Dnd thereby 8 measure of disle_L,ic breakdown product production in said high voltsge discharge apparatus. The D.C. voltage level may be caliLr~Led against measured di~lecLdc breP'~~o~ n product production in the spparatus, to enable measurement of the actual dielccllic breakdown product production from the measured D.C. voltage level.
The prcsenl invention can be realized with a dielectric breakdown circuit comprising 8 capacitive transducer, a first high pass filter, an optical coupler powered by an isolated direct current power supply, a two-stage radio frequency (RFI c..llpl;~ie" a second high CA 0223~2~6 1998-04-17 WO 97/14973 PCT/lB96/01122 pass filter, an s.ll~liri~/diode pump, a linearizer, a low pass filter and a scalin~ r;...,~Jl;rier.
The capacitive transducer is co~ to the sccond~r~ wil~d;..~ of a high voltage transformer, which is used to provide high voltage pulses to 8 corona discharge ozone ~~e.~ or. The cApacitive transducer thus capacitively senses individual corona S discharge pulses that are i.. ,posed on the voltage signal of the secondary winding of the high voltage ~a"sru,."er. Lower frequencies, such as the high voltage drive frequency, are filtered out of the capacitive transducer signal in the first high pass filter. The optical coupler electrically isolates the processing circuitry from the high voltage transformer coupling. An isolated direct current power supply separates the power source of the optical coupler from the power source used for the processing circuitry, thereby reducing electrical noise induced by the transformer circuitry~ The capacitive transducer signal is then amplified in the two-stage RF amplifier. Low frequencies sre further reduce~ in the second high pass filter. The direct current voltage is amplified and voltage ripple is reduced in the a...~ ier/diode pump. The linearizer provides a 1~ voltage-dependent adjustment to the gain of the amplifier/diode pump to create linear voltsge output values. Any remaining voltage ripple in the direct current voltage is re~ ced in the low pass filter, then F.n~.liricd in the scaling amplifier for input to a analog-to-digital converter snd then to a ..-iclol,rc,cessor. A photospectrometer or other device is used to calibrate the direct current voltage values in relation to the actual level of ozone being produced. The direct current voltage is then directly related to the formation of dielectric breakdown products in the presence of high voltage.
In summary, in the prere--ed embodiment, corona discharge pulses in an ozone generator are capacitively sensed. First, low frequencies are filtered out of the sensed signal. The sensed signal is then elecl~ic&:ly isolated by an optical coupler, amplified, rectified, linearized, filtered and an., I;ried aç~ain into a ripple-free direct current vottage signal. After caliLr"Lion to the actual ozone being produced, this direct current voltage signal is directly related to ozone production in the ozone generator.
From the above descriptive summary it is apparent how the present invention over~u, ~ .es the sho. Lcul . .ings of the above-mentioned prior art.
ACCGI~jll91Y, an object of the ,u.ese.-L invention is to provide cost effective apparatus and rnethods to measure the breakdown of a dielectric in the pre~ence of high voltage, CA 0223~2~6 1998-04-17 Wo 97/14973 PCT/IB96/011Z2 thereby providing a very cost effective measuring and signal condilion;--g circuit.
Another object of the present invention is to provide apparatus and method for measuring the breakdown products that are created by the breakdown of the dielectric.
Another object of the prese"~ invention is to provide apparatus and method for measuring ozone production in an ozone generator using the corona discharge principle.
Another object of the present invention is to provide an instrument for the aforementioned purposes, which is comprised completely of solid state elsctronics and is therefore very rugged.
Another object of the present invention is tO provide ~or the aforementioned purposes a very light weight and compact instrument, which is suitable for installations where space snd portability is important.
Anoth~r object of the present invention is to provide for the aforementioned purposes a completely solid state instrument with a linear output signal.
Other objects and advantages of the present invention will become apparent to those skilled in the art upon reading the following detailed description and claims inconjunction with the accor.,panying drawings which are appended hereto.
BRIEF DF.~CRIPTION OF THF DRAWINt;S
In order to facilitate a fuller understanding of the present invention reference may now be made to the appended drawings. The drawings should not be construed as limiting O the present invention, but are intended to be exer"pla, y only.
Fi~ure 1 is a schematic block diagram of a dielectric breakdown measL-,ernent circuit according to the present invention which may be used for measurement of ozone production; and Fi~ure 2 is a ;.CI~ LiC block d;n~3m of a hi~h voltage l.a,.aru,.,.er with a capscitive transducer affixed thereto accor~l;..g to the plascnL invention.
DETAII Fn DESCRIPTION OF TH} pREFFRRFn FMBODIMF~IT
Referring to Figure 1, there is shown a schematic block diagram of a dielectric breakdown measurement circuit 10 accorciir~ç3 to the present invention. The dielectric breakdown measu.~,."enl circuit 10 comprises a capacilive transducer assembly 12, a first high pass filter 14, an optical coupler 16 powered by an isolated direct current power supply 18, a two-stage rsdio frequency (RF) amplifier 20, a second high pass filter 22, an amplifierldiode pump 24, a linearizer 26, a low pass filter 28 and a scaling amplifier 30. The output from ampiifier 30 may be provided to an analog-to-digital (A/D) - converter 32, which in turn provides a signal to a microprocessor 34.
The capacitive transducer asse...bly 12 is a capacitive coupling to the secondary winding of a high voltage L,~,nsrGr."er, which is used to provide high voltage pulses to a corona discharge ozone generator. Such a corona discharge ozone generator is ~;cclosed in U.S. Patent No. 5,094,882, entitled Ozone Generator, which issued March 10, 1~92, and such a high voltage Lrar-stGr",er is disclosed in U.S. Patent No.
~,443,800, ellLiLled Pulse Train Generating Circuit for Control of an Ozone Generating Means, which issued August 22, 1g95. The disclosures of these patents, which have a common inventor with the ~lese.lL invention, are hereby incorporated by reiere"ce herein.
The c~pacitive transducer assembly 12 capacitively senses individual corona discharge pulses tllat are imposed on the voltage signal of the secondary winding of the high voltage L~a~arOIIller. Lower frequencies, such as the high voltage drive frequency, are filtered out of the transducer signal in the first high pass filter 14. The optical coupler allows the p~ssage of the transducer signal, while isolating the electrical noise presen~
in the high voltage L~..na~un,~er circuitry The isolated direct current power supply 18 aids in ~cl, _.ri"g this elccl~ical isolation. The optical coupler 16 may be of a conventional type, based ê.9. upon an LED light source and a spaced pboLGd;ode sensor. The transducer signal is then amplified in the two-stage RF amplifier 20. Low CA 0223~2~6 1998 - 04 -17 WO 97/14973 PCTtIB96/01122 fr~quencies E~re further r~duced in the second hi~h pass filter 22. Th9 voltage pulses are .A.I~pliried and mod~lated by a diode pump circuit in the amplifierldiode pump 24, which provides a measure of the ampiitude and frequency of the pulses. The linearizer 26 provides a voltage dependent adjustment to the gain of the amplifier/diode pump 24 to create linear voltage output values. Any remaining voltage ripple in the direct current voltage is reduced in the low pass filter 28. The direct current voltage is amplified in the scaling amplifier 30. After calibration to the actual dielectric product, e.g., ozone, being produced, the direct current voltage is now directly related to the breakdown of the dielectric in the presence of high voltage, and can then be converted into digital form by the A/D converter 32. The microprocessor 34 can then process the diç~ital data so as to provide a display of the breakdown of the dielectric, which in the present embodiment is the amount of ozone being produced by the ozone generator. The ,.icroprocessor 34 can then control the rate of dielectric product, e.g. ozone, production in a high voltage ozone generator.
The direct current voltage levels provided from scaling amplifier 30 are calil~.~ted to the actual levels of ozone being produced as measured by a convenLiGnal spectrophotometer. This is effected by e:,Lal~lishi.~g a series of points relating measured voltage levels to measured ozone concenL~aLions. The established relationship thereb enables direct calibration of readout voltage levels in terms of ozone concentration.
It should be noted that the sequence of the signal conditioning described above may be varied and, in fact, some of the above-descnLed signal co"diLioniog functions may be Ol l li LLed .
The overall function of the transducer signal co:.diLionillg in the dielectric breakdown measuring circuit 10 is to provide a means for converting sensed corona discharge pulses into a direct current voltage which is represenLaLive of the frequency and magnitude of occurrence of these corona discharge pulses. The generation of the corona discharge pulses is relatively uniform if the physical dimensions ~i.e. gap size) of the ozone generator are held fixed and the composition and flow rate of gases flowing through the ozone generator are properly regulated. However, the actual amount of ozone production in the ozone gene~aLur is dependent on the frequency and magnitude of the corona disc~,a,ye pulses. The present invention is therefore directed toward CA 0223~2~6 1998-04-17 ~ena;,.S~ corona discharge pulses and then converting the sensed corona Jiscl.alçlc pulses into a direct current voltaç~e hsving a voltage level that is ~:pras&.,L~ e of the frequency and ",a~uil.lde of occurrence of the sensed corona discharge pulses snd thereby directly related to the ozone production in the ozone generator.
S~ It should be noted that the capacitive transducer assembly 12, which consists of an aluminum plate, need not be actually affixed to the insulating material surrounding the secondary winding in the high voltage transformer, but must merely be in close proximity to the secondary winding in the high voltage transformer so as to sense the individual corona discharge pulses.
Referring to Figure 2, there is shown a schematic block dlagram revealing a typical physical relationship between a high voltage transformer 40 and a corona discharge pulse capacitive transducer 42 according tO the present invention. The high voltage L,ansrG",-er 40 co",prises a primary winding tnot shown) and a high voltage secondary winding 44.
-In this par~icular embodiment, the capacitive transducer 42 comprises an aluminum plste, approximately 10 x 10 mm square, which is fixed to the insulating material surrounding the high voltage secondary winding 44. The high voltage secondary winding 44 provides high voltage pulses to an ozone generator ~not shown). These high voltage pulses produce corona discharges in the ozone generator. The capacitive transducer 42 capacitively senses these corona discharges as pulses of electrical charge from the high voltage secondary winding 44. These sensed corona discharç~e pulses may then be signal conditioned by the dielectric breakdown measurement circuit accGrdi, ,9 to the present invention.
With the present invention now fully described, it can thus be seen that the objects set 2~ forth above are efficiently attained and, since certain changes may be made in the above-described embodiments without departing from the scope of the invention, it is intended that all matter contained in the above desc.i~Lion or shown in the acco...p~""~ing drawings shall be i"~er~e~ed as illustrative and not in a limiting sense.
Claims (24)
1. Apparatus for measuring dielectric breakdown product production in a high voltage discharge apparatus, said apparatus comprising:
means for sensing corona electrical discharge pulses from a winding in a voltagetransformer providing electrical charging pulses to said high voltage discharge apparatus and generating an electrical signal in accordance with the sensed pulses; and means for converting said electrical signal into a D.C. voltage the level of which is a function of the frequency of occurrence and magnitude of said sensed electrical discharge pulses and thereby a measure of dielectric breakdown product production in said high voltage discharge apparatus; and means for calibrating said direct current voltage level against measured dielectric breakdown product production in said apparatus, to enable measurement of the actual dielectric breakdown product production from the measured direct current voltage level.
means for sensing corona electrical discharge pulses from a winding in a voltagetransformer providing electrical charging pulses to said high voltage discharge apparatus and generating an electrical signal in accordance with the sensed pulses; and means for converting said electrical signal into a D.C. voltage the level of which is a function of the frequency of occurrence and magnitude of said sensed electrical discharge pulses and thereby a measure of dielectric breakdown product production in said high voltage discharge apparatus; and means for calibrating said direct current voltage level against measured dielectric breakdown product production in said apparatus, to enable measurement of the actual dielectric breakdown product production from the measured direct current voltage level.
2. The apparatus as defined in claim 1, wherein said means for sensing comprises a capacitive transducer coupling to said winding in said voltage transformer.
3. The apparatus as defined in claim 2, wherein said winding is a secondary winding.
4. The apparatus as defined in claim 1, wherein said means for converting comprises a first high pass filter for filtering out lower frequencies from the electrical signal produced from said sensing means.
5. The apparatus as defined in claim 4, wherein said means for converting further comprises an optical coupler powered by an isolated direct current power supply, for receiving the signal from said first high pass filter, while isolating the processing circuitry from the high voltage transformer coupling.
6. The apparatus as defined in claim 5, wherein said means for converting further comprises a first two-stage amplifier for receiving and amplifying the filtered signal from said optical coupler.
7. The apparatus as defined in claim 6, wherein said first two-stage amplifier is an RF amplifier.
8. The apparatus as defined in claim 6, wherein said means for converting further comprises a second high pass filter connected to the output of said two stage amplifier, for filtering out lower frequencies in said amplified signal.
9. The apparatus as defined in claim 8, wherein said means for converting comprises a second amplifier connected to the output of said second high pass filter for amplifying said D.C. voltage signal.
10. The apparatus as defined in claim 9, wherein said means for converting further comprises a diode pump for providing a measure of the amplitude and frequency of the said D.C. voltage signal.
11. The apparatus as defined in claim 10, wherein said means for converting further comprises a linearizer for adjusting the actual values of the said D.C. signal to a linear range.
12. The apparatus as defined in claim 11, wherein said means for converting further comprises a low pass filter for receiving the signal from said linearizer and filtering out higher frequencies in the D.C. voltage signal.
13. The apparatus as defined in claim 12, wherein said means for converting further comprises a scaling amplifier for receiving and amplifying said D.C. voltage signal.
14. An apparatus for measuring the breakdown of a dielectric in the presence of high voltage by sensing electrical pulses from a winding in a transformer and then converting said sensed electrical pulses into a D.C. voltage the level of which represents the magnitude of said sensed electrical pulses, said device comprising:
means for sensing electrical pulses from a winding in a transformer; and means for converting said sensed electrical pulses into a D.C. voltage which is representative of the magnitude of said sensed electrical pulses.
means for sensing electrical pulses from a winding in a transformer; and means for converting said sensed electrical pulses into a D.C. voltage which is representative of the magnitude of said sensed electrical pulses.
15. An apparatus for measuring the breakdown of a dielectric in the presence of high voltage by sensing electrical pulses from a winding in a transformer and then converting said sensed electrical pulses into a D.C. voltage the level of which represents the frequency of occurrence and magnitude of said sensed electrical pulses, said device comprising:
-means for sensing electrical pulses from a winding in a transformer; and means for converting said sensed electrical pulses into a direct current voltagewhich is representative of the magnitude and frequency of occurrence of said sensed electrical pulses.
-means for sensing electrical pulses from a winding in a transformer; and means for converting said sensed electrical pulses into a direct current voltagewhich is representative of the magnitude and frequency of occurrence of said sensed electrical pulses.
16. An apparatus for measuring the breakdown of the dielectric in the presence of high voltage represents the frequency of occurrence and the magnitude of said sensed electrical pulses, said method comprising:
means for sensing electrical pulses from a winding in a transformer; and means for converting said sensed electrical pulses into a D.C. voltage which is representative of the frequency of occurrence and the magnitude of said sensed electrical pulses.
means for sensing electrical pulses from a winding in a transformer; and means for converting said sensed electrical pulses into a D.C. voltage which is representative of the frequency of occurrence and the magnitude of said sensed electrical pulses.
17. A method for measuring the breakdown of a dielectric in the presence of highvoltage by sensing electrical pulses from a winding in a transformer and then converting said sensed electrical pulses into a D.C. voltage the level of which is indicative of the frequency and magnitude of said sensed electrical pulses, said method comprising the steps of:
sensing electrical pulses from a winding in a transformer; and converting said sensed electrical pulses into a D.C. voltage the level of which is representative of the frequency and magnitude of said sensed electrical pulses.
sensing electrical pulses from a winding in a transformer; and converting said sensed electrical pulses into a D.C. voltage the level of which is representative of the frequency and magnitude of said sensed electrical pulses.
18. A method for measuring ozone production in an ozone generator using the corona discharge principle, said method comprising the steps of.
sensing electrical discharge pulses from a winding in a voltage transformer, said voltage transformer providing electrical charging pulses to a corona discharge ozone generator; and converting said sensed electrical discharge pulses into a D.C. voltage the level of which is representative of the frequency and magnitude of said sensed electricaldischarge pulses and thereby directly related to ozone production in said coronadischarge ozone generator.
sensing electrical discharge pulses from a winding in a voltage transformer, said voltage transformer providing electrical charging pulses to a corona discharge ozone generator; and converting said sensed electrical discharge pulses into a D.C. voltage the level of which is representative of the frequency and magnitude of said sensed electricaldischarge pulses and thereby directly related to ozone production in said coronadischarge ozone generator.
19. The method as defined in claim 18, further comprising the step of providing a ozone production in said corona discharge ozone generator based on the level of said direct current voltage by changing the rate at which said voltage transformer provides electrical charging pulses to said corona discharge ozone generator.
20. The method as defined in claim 19, further comprising the step of providing a display indicating the amount of ozone production in said corona discharge ozonegenerator based on the level of said direct current voltage.
21. A method for measuring ozone production in a high voltage discharge apparatus comprising:
sensing corona electrical discharge pulses from a winding in a voltage transformer providing electrical charging pulses to said high voltage discharge apparatus and generating an electrical signal in accordance with the sensed pulses;
converting said electrical signal into a D.C. voltage the level of which is a function of the frequency of occurrence and magnitude of said sensed electrical discharge pulses and thereby a measure of ozone production in said high voltage discharge apparatus; and calibrating said direct current voltage level against measured ozone production in said apparatus, to enable measurement of the actual ozone production from the measured D.C. voltage level.
sensing corona electrical discharge pulses from a winding in a voltage transformer providing electrical charging pulses to said high voltage discharge apparatus and generating an electrical signal in accordance with the sensed pulses;
converting said electrical signal into a D.C. voltage the level of which is a function of the frequency of occurrence and magnitude of said sensed electrical discharge pulses and thereby a measure of ozone production in said high voltage discharge apparatus; and calibrating said direct current voltage level against measured ozone production in said apparatus, to enable measurement of the actual ozone production from the measured D.C. voltage level.
22. The method of claim 21, wherein said discharge pulses are sensed by a capacitive coupling.
23. The method of claim 22, wherein said winding sensed is a secondary winding.
24. The method of claim 21, wherein said electrical signal being converted to said D.C. signal is conditioned by filtering out lower frequencies, and by passing the signal through an optical coupler powered by an isolated direct current power supply, for isolating the signal processing from the high voltage transformer coupling.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US54630095A | 1995-10-20 | 1995-10-20 | |
| US08/546,300 | 1995-10-20 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2235256A1 true CA2235256A1 (en) | 1997-04-24 |
Family
ID=24179787
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2235256 Abandoned CA2235256A1 (en) | 1995-10-20 | 1996-10-21 | Method and apparatus for utilizing dielectric breakdown for indirect measurement purposes |
Country Status (4)
| Country | Link |
|---|---|
| JP (1) | JPH11513798A (en) |
| AU (1) | AU7143396A (en) |
| CA (1) | CA2235256A1 (en) |
| WO (1) | WO1997014973A1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6280633B1 (en) | 1999-12-01 | 2001-08-28 | Fantom Technologies Inc. | Ozone sensor and method for use of same in water purification system |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2334656B (en) * | 1998-02-24 | 2000-10-25 | Peter John Niccolls | Ozone generator |
| EP1507743A1 (en) * | 2002-03-21 | 2005-02-23 | Tem GmbH | Method for operating an ozone generator and corresponding ozone generator |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4245187A (en) * | 1979-05-10 | 1981-01-13 | The United States Of America As Represented By The Secretary Of The Navy | VLF Capacitor corona detection |
| JPS62206454A (en) * | 1986-03-06 | 1987-09-10 | Toshiba Corp | Transformer for instrument |
| JP2884788B2 (en) * | 1991-02-15 | 1999-04-19 | 富士電機株式会社 | Partial discharge measuring device for resin mold transformer |
| US5443800A (en) * | 1993-06-01 | 1995-08-22 | Liftech Corporation | Pulse train generating circuit for control of an ozone generating means |
-
1996
- 1996-10-21 AU AU71433/96A patent/AU7143396A/en not_active Abandoned
- 1996-10-21 WO PCT/IB1996/001122 patent/WO1997014973A1/en active Application Filing
- 1996-10-21 CA CA 2235256 patent/CA2235256A1/en not_active Abandoned
- 1996-10-21 JP JP9515664A patent/JPH11513798A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6280633B1 (en) | 1999-12-01 | 2001-08-28 | Fantom Technologies Inc. | Ozone sensor and method for use of same in water purification system |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH11513798A (en) | 1999-11-24 |
| AU7143396A (en) | 1997-05-07 |
| WO1997014973A1 (en) | 1997-04-24 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US6762607B2 (en) | Electrostatic discharges and transient signals monitoring system and method | |
| Liston et al. | A contact modulated amplifier to replace sensitive suspension galvanometers | |
| US4176555A (en) | Signal amplifier system for controlled carrier signal measuring sensor/transducer of the variable impedance type | |
| US4429702A (en) | Apparatus for measurement of acoustic volume | |
| US4648279A (en) | Method of and device for measuring flow rate by electromagnetic induction | |
| CA2235256A1 (en) | Method and apparatus for utilizing dielectric breakdown for indirect measurement purposes | |
| EP1426771A4 (en) | Impedance measuring circuit and capacitance measuring circuit | |
| US4137766A (en) | Integral field magnetic flowmeter | |
| SE9603798L (en) | Device for monitoring partial discharges in an electric high-voltage apparatus or high-voltage equipment | |
| JPS55155258A (en) | Device for measuring characteristic of gapless arrester | |
| US4928059A (en) | Sinusoidal current sense and scaling circuit | |
| Train et al. | The detection of partial discharges in high voltage potential transformers in service | |
| JPH06241856A (en) | Capacity type electromagnetic flowmeter | |
| JPH04283910A (en) | Apparatus for inspection converter transformer | |
| RU2079849C1 (en) | Device for measuring currents | |
| SU1522085A1 (en) | Vortex device for measuring dimensions and concentration of metal particles in liquid | |
| SU577417A1 (en) | Method and apparatus for dynamic calibration of pressure sensors | |
| SU1084628A1 (en) | Device for measuring force | |
| DE3783869D1 (en) | FLOW-COMPENSATED CURRENT TRANSFORMER. | |
| SU875317A1 (en) | Magnetometer | |
| SU1250931A1 (en) | Method and apparatus for separate measuring magnetic permeability and electrical conductivity | |
| SU693277A1 (en) | High-voltage meter of breakthrough voltages of transistors | |
| SU1737385A1 (en) | Device for testing properties of magnetic materials | |
| SU1307407A1 (en) | Device for measuring parameters of barkhausen effect | |
| RU1832177C (en) | Transformer-type displacement transducer |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Dead |