开关电源发展与压电材料应用展望

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1、TRANSONER Overview.Piezoelectric transformers for CCFL backlightingFace Electronics,LC.,Virginia,USAFace Electronics,LC.,Virginia,USADecember 5,2001Dr.Alfredo Vzquez Carazo427 W.35th St.Norfolk,VA USA Fax:757.624.2128 Charlie Elliott,Pulse Engineering TRANSONER Magnetic TransformerRosen-type Piezo-T

2、ransformerTransoner Piezo-TransformerUnits in cmTransformers for CCFL backlightingPiezoelectricity:Basic concepts TRANSONER INVERSE PIEZOELECTRIC EFFECTElectrical to Mechanical energy conversionDIRECT PIEZOELECTRIC EFFECTMechanical to Electrical energy conversion Discovered in Japan early in the 195

3、0s.These materials are usable at least to 250o.Rosen-type Piezoelectric Transformers P LOAD Input Part Output Part Uin h L L P Technical literature refers the name of PIEZOTRANSFORMER to the device which was initially developed for Charles A.Rosen and Keith Fish(1954).Source:Thesis Alfredo VazquezBa

4、ckground on Piezoelectric Transformers TRANSONER Background on Piezoelectric Transformers TRANSONER Types of Rosen-piezoelectric transformers TRANSONER Family PhotosBackground on Piezoelectric Transformers(PTs)Rosen:First Patent on PTsBerlincourt:Ballast for gaseous discharge lamp(Vermitron Corp.)PT

5、s for TV receivers HV for cathode ray.(Denji Onkyo Limited,Matsushita,Motorola,RCA Corp.)PTs for triggering power switches gates with galvanic decoupling(Triacs,Tiristors,Mosfets,etc.):Siemens,General Electric.PTs for backlight CCFL in lap-top computers.(NEC,Murata,Matsushita,Taiheiyo,Tamura,Motorol

6、a,Tokin,etc.)195870s70s80s85s to presentIncrease Power Density:Smaller sizesCurrent targetBackground on Piezoelectric Transformers TRANSONER What was wrong with“those”Piezo-trafosSUCCESFULLY IMPROVED SINCE 1985sMaterialDriving CircuitryManufacturing ProcessMountingPZT-Material under development (195

7、4)(low Q,high dielectric losses,low coupling coef.).High Sintering Materials ExpensiveNo tape-casting techniques Limit on sizesDouble Polarization Process no optimized Reliable housing techniques under developmentElectronic circuit based on discrete componentsLimited POWER CAPABILITIES(5 W/cm3)Power

8、Low VoltageMechanical Vibration(Resonance)High VoltageInverseEffectDirectEffectFlat and thin designNo electromagnetic noise/no coilsHigh power-density and step-up ratioHigh efficiencyNon-flammableINPUTOUPUTPiezoelectric BodyPPLOADHigh immunity to external EMI,low profile,compactBackground on Piezoel

9、ectric Transformers TRANSONER How do they operate?.Resonance010203040506070Input Impedance open circuit conditionsImpedance Ohms1st longitudinal mode(fundamental)3rd longitudinal mode100200300400500600Frequency kHz-100-80-60-40-200204060Phase DegreesfRfABackground on Piezoelectric Transformers TRANS

10、ONER INPUT OUPUT Piezoelectric Body P P LOAD /2 mode3/2 mode INPUT OUPUT Piezoelectric Body P P LOAD P TRANSONER Features:Simple construction without windingsNo winding shorts during operationNo magnetic field involve in the operation(reduced RF and EMI)Low profileHigh efficiency Non-flammable98%Typ

11、ical EfficiencyNo High Voltage“Corona Effect”Pure Sine Wave Output(Minor Distortion)Surface Temperature raising T 35K due to their excellent thermal dissipation behavior.Piezoelectric vs.Magnetic 5W 50W 100W 220W 1kV 10V 5kV 10kV Material Improvements Dimensional Redesign Modular Design Power Delive

12、ry W Output Voltage Vp Step-up ratio 50-100 Input Voltage in CCFL applicat.(NEC,Tokin,Murata,etc)JAPAN(1985-2000)Improvements USA 1958 Rosen-type P P T6T1T3 USA 1998 TRANSONER TECHNOLOGY(Face Inter.Corp)New Piezo-Trafo technologies TRANSONER Insulation Layer Output Layer Input Layer P P T3-HV Transo

13、ner P P CONSTRUCTION COUPLING AREAPOLING DIRECTIONSTRESS DIRECTION(LONGITUDINAL vs.RADIAL+SHEAR)TRANSONER Rosen vs.Transoner Insulation Layer Output Layer Input Layer P P Input PartOutput Partk33+k31k33+k31+k15K15 31 TRANSONER Rosen vs.TransonerTRANSONER ADVANTAGESSimple achievement of ISOLATION cap

14、abilities 35 kV by adding a isolation layerThe stack concept allows a LARGER MECHANICAL COUPLING AREA and thus a higher power densityINPUT AND INPUT CAPACITANCES can be independently designed without having the same thickness.Larger step-up ratiosAs a result SMALLER SIZES and more compact and effici

15、ent inverter can be developedRosen-typeTransoner-typeELECTRICAL ENERGYVoltage,currentELECTRICAL ENERGYVoltage,currentPPTransducerActuatorTV outV inFigure of a simple two-layer TransonerP=Polarization directionT=Stress directionTransoner:Types and specifications TRANSONER Patent Notice:Technology dis

16、closed on this page covered by one or more issued or pending U.S.and International patents owned by face International Corporation,Norfolk,Virginia,USA.Output Layer Input Layer RL P P PPInsulation LayerOutput LayerInput LayerRLT1-Type TransonerLarge PowerStep-up and Step-downMedium,low impedance loa

17、ds 200-1k (Linear fluorescent)T3-Type TransonerMedium-low Power(5-8W)Very high Step-up(200)Large impedance loads 50k -300k (CCFL)MiniT1 Transoner Mini-size(5mm2 x 1mm)Step-upMediumimpedance loads 200-1k (PDA,CellPhones)Transoner:Types and specifications TRANSONER Typical High Voltage Transoner Type-

18、3 DevicesSpecificationsType T3:High Voltage Transoner Current Output(max)Power(max)Frequency(range)GainIsolation VoltageEfficiency(max)Thickness-mmLength-mmWidth-mm4-5 W65 kHz to 92 kHz.007 A1:20 to 1:90NA98+%2.92-4.0621.59-29.977.82-8.38Non-IsolatingTransoner:Types and specifications TRANSONER Oper

19、ation Point:Maximum EfficiencyApproach to the Operation Principle TRANSONER General BehaviorApproach to the Operation Principle TRANSONER Load Dependence:CCFL starting up and Continuous operationApproach to the Operation Principle TRANSONER Protections Rectifier Load Piezoelectric Transformer DC AC

20、Converter DC Voltage Dimming Frequency Tracking General principle for driving a piezoelectric resonant transformer General Block Diagram TRANSONER Driving Circuitry for Piezoelectric TransformersPiezo-Trafo Equivalent Circuit Cd1 C L R Cd2 1:N C=Equivalent StiffnessR=Equivalent Mechanical Resistance

21、L=Equivalent mass TRANSONER Driving Circuitry for Piezoelectric TransformersPiezoelectric transformer input sections are characterized by a shunt input capacitance which may exceed tens of nano-farads.Two ways to drive a Piezoelectric TransformerSquare-wave signal:PWM convertersSine-wave signal:Reso

22、nant convertersLarge harmonic contents(Input drive harmonics may be rejected by the high-Q transformer thereby reducing drive efficiency.Drive harmonics can excite spurious modes in the PT which will be difficult to suppress.The circulating energy through the shunt input capacitance Cd1 characterist

23、ic of the input section of PT generate dielectric losses(turn-on losses).Zero Voltage Switching Technique:use a square switching signal with ZVS technique to minimize switching losses.DC-AC Driving Circuit Techniques TRANSONER Driving Circuitry for Piezoelectric Transformers Driver Load Feedback VDC

24、 Class-E DC/AC converterHalf-bridge DC/AC converterFull-bridge DC/AC converter TRANSONER Driving Circuitry for Piezoelectric Transformers Driver VDC P P Load Driver VDC Load L S1 S2 P P Driver VDC L S1 S2 P P Push-pull DC/AC converter Vgs t Vds1 t Vin t L1 L2L1 ZVS technique Non-ZVS region ZVS regio

25、n Cin L Driving Circuitry for Piezoelectric Transformers TRANSONER Where would one use it?High Voltage Low Power applications:CCFL Lamp for LCD in Laptop computersHigh Voltage ignition+Step-down steady state Medium Power applications:Fluorescent lampsPower supply:AC/DC converters Cellular Phones:EL displaysPotential Piezo-Transformers ApplicationsPatent Notice:Technology disclosed on this page covered by one or more issued or pending U.S.and International patents owned by Face International Corporation,Norfolk,Virginia,USA.TRANSONER