1 Prof. S. Ben-Yaakov, Power Electronics of Piezoelectric Elements, - PDF document

Prof. S. Ben-Yaakov, Power Electronics of Piezoelectric Elements, June 2006 [1] Power Electronics of Piezoelectric Elements Shmuel (Sam) Ben-Yaakov Power Electronics Laboratory Department of Electrical and Computer Engineering Ben-Gurion University of the Negev P.O. Box 653, Beer-Sheva 84105, ISRAEL Phone: +972-8-646-1561; Fax: +972-8-647-2949; Email: sby@ee. bgu.ac.il; Website: www.ee.bgu.ac.il/~pel Gordon Seminar, Tel-Aviv University, June 2006 Prof. S. Ben-Yaakov, Power Electronics of Piezoelectric Elements, June 2006 [2] OUTLINE 1. Introduction • Piezoelectricity • Brief overview of Piezoelectric devices • Actuators • Vibrating vans • Motors • Micro-PowerGenerators/Dampers • Transformers • Miscellaneous Prof. S. Ben-Yaakov, Power Electronics of Piezoelectric Elements, June 2006 [3] OUTLINE (Cont.) 2. Models of Piezoelectric devices 3. Drivers 4. Rectifiers 5. PT based CCFL Ballasts • The stability issue • Envelope Simulation • Thermal effects 1

Prof. S. Ben-Yaakov, Power Electronics of Piezoelectric Elements, June 2006 [4] 1. Introduction Piezoelectricity � Discovery-1880 by Pierre and Jacques Curie – Sonar transducer – Pickup and microphone – High frequency quartz resonators Prof. S. Ben-Yaakov, Power Electronics of Piezoelectric Elements, June 2006 [5] Piezoelectricity (Cont.) � 1940- Piezoelectric Ceramics e.g. lead-zirconate-titanate (PZT), lead-titanate (PbTiO 2 ), lead-zirconate (PbZrO 3 ), and barium-titanate (BaTiO 3 ) Plastic Piezo material, PVDF (Polyvinylidene fluoride) – Powerful “sonars” – Systems of piezo-ignition – Ceramic tone-transducers, Buzzers, Speakers – Piezoelectric motors an actuators – Piezoelectric transformers – “Exotic” devices: damper, power sources… Prof. S. Ben-Yaakov, Power Electronics of Piezoelectric Elements, June 2006 [6] Range of Applications � TechOnLine – Applications for Piezoelectric Ceramics.htm 2

Prof. S. Ben-Yaakov, Power Electronics of Piezoelectric Elements, June 2006 [7] OBJECTIVE Overview of Piezoelectric devices and associated electronics from the Power Electronics point of view. This seminar relates to modern piezoelectric devices with particular emphasis on piezoelectric transformers. Prof. S. Ben-Yaakov, Power Electronics of Piezoelectric Elements, June 2006 [8] 1. Brief overview of piezoelectric devices The piezoelectric effect Electrode V Piezoelectric material V • Mechanical � electrical interaction • Electrical field � Mechanical Stress Prof. S. Ben-Yaakov, Power Electronics of Piezoelectric Elements, June 2006 [9] Compressed notation and matrix arrays: [ ] [ ] [ ] [ ] [ ] − i , j , k takes values 1 3 = E ⋅ − ⋅ S s T d E p pq q kp k ] [ ] [ ] [ ] [ − p , q takes values 1 6 [ ] T = ⋅ + ε ⋅ D d T E i iq q ik k = S Strain companent where p = T Stress companent q = E electric field k = D electric displaceme nt i ∂ S p E = = s compliance cons tan t at cons tan t electric field pq ∂ T q = E const = d Piezoelect ric cons tan t kp T ε = permittivi ty cons tan t at cons tan t stress ik 3

Prof. S. Ben-Yaakov, Power Electronics of Piezoelectric Elements, June 2006 [10] Constants – IEEE Standard table_piezo_nomenklature_01.jpg table_piezo_nomenklature_02.jpg Prof. S. Ben-Yaakov, Power Electronics of Piezoelectric Elements, June 2006 [11] Actuators Stack of piezoelectric elements L Features and Applications: L • Small deflection ( µ m range) • Static and dynamic applications • Light deflection • Positioning, no friction or backlash • Valve control Prof. S. Ben-Yaakov, Power Electronics of Piezoelectric Elements, June 2006 [12] XY Positioning 200 nm span 4

Prof. S. Ben-Yaakov, Power Electronics of Piezoelectric Elements, June 2006 [13] Bimorph Benders Parallel Bimorph Serial Bimorph •Same idea as bi-metal •Large deflection, mm range Prof. S. Ben-Yaakov, Power Electronics of Piezoelectric Elements, June 2006 [14] Vibrating Van Bimorphs Piezoelectric element Van Base Electrical terminals ∆ x − p p Prof. S. Ben-Yaakov, Power Electronics of Piezoelectric Elements, June 2006 [15] Bi-Morph Actuators and Vibrating Vans Features and Applications: • Large deflection • Light Choppers • Remote operation • Valve control • Fan 5

Prof. S. Ben-Yaakov, Power Electronics of Piezoelectric Elements, June 2006 [16] Piezoelectric motors electrode B piezo ceramic electrode A Elliptic A movement common B stage electrode C piezo actuator driver S 1 S 2 V AC • Nanomotion Ltd. Israel stator Prof. S. Ben-Yaakov, Power Electronics of Piezoelectric Elements, June 2006 [17] Operation Demo Nano_motor.avi Prof. S. Ben-Yaakov, Power Electronics of Piezoelectric Elements, June 2006 [18] Nanomotion’s NanoLens 6

Prof. S. Ben-Yaakov, Power Electronics of Piezoelectric Elements, June 2006 [19] Piezoelectric Motors Features and Applications: • Linear motion • Circular motion • Sub-micron motion and positioning • Small size • Vacuum compatible • Camera lenses • HD drive • Microelectronics manipulators Prof. S. Ben-Yaakov, Power Electronics of Piezoelectric Elements, June 2006 [20] Micro-Power Generators (Mechanical to Electrical energy harvesting) MASS Mechanical Vibration Prof. S. Ben-Yaakov, Power Electronics of Piezoelectric Elements, June 2006 [21] Micro-Power Generator V out Piezoelectric element Silicon beam 63 Ni radioisotope emitter [12] 7

Prof. S. Ben-Yaakov, Power Electronics of Piezoelectric Elements, June 2006 [22] MIT’s Piezo Tennis Shoe Prof. S. Ben-Yaakov, Power Electronics of Piezoelectric Elements, June 2006 [23] Dampers Beam V in Shaking table Piezoelectric element Prof. S. Ben-Yaakov, Power Electronics of Piezoelectric Elements, June 2006 [24] Sports Active Damping Patent 8

Prof. S. Ben-Yaakov, Power Electronics of Piezoelectric Elements, June 2006 [25] Ski Damping CEDRAT TECHNOLOGIES & SKI ROSSIGNOL Prof. S. Ben-Yaakov, Power Electronics of Piezoelectric Elements, June 2006 [26] Dampers experiment http://live.pege.org/2005-material/oscillation-damping.htm Prof. S. Ben-Yaakov, Power Electronics of Piezoelectric Elements, June 2006 [27] Micro-Power Generators and Dampers Features and Applications: • Active suspension • Skis • Motorcycles • Remote energy sources • Tennis shoes • Structures 9

Prof. S. Ben-Yaakov, Power Electronics of Piezoelectric Elements, June 2006 [28] Piezoelectric Transformers V o V in V in PT R L V o [15] Prof. S. Ben-Yaakov, Power Electronics of Piezoelectric Elements, June 2006 [29] Transformer examples T V in P P V out • Radial mode [16] Prof. S. Ben-Yaakov, Power Electronics of Piezoelectric Elements, June 2006 [30] Rosen Type Piezoelectric Transformer potential V S x displacement x support point V P V S poling [15-18, 70] primary secondary • High voltage gain part part 10

Prof. S. Ben-Yaakov, Power Electronics of Piezoelectric Elements, June 2006 [31] Rosen Type Piezoelectric Transformer Multilayer A A V in • Higher voltage transfer ratio Prof. S. Ben-Yaakov, Power Electronics of Piezoelectric Elements, June 2006 [32] Step Down Prof. S. Ben-Yaakov, Power Electronics of Piezoelectric Elements, June 2006 [33] Characteristics of Piezo transformers � Advantages – Potentially low costs – Compact size – High efficiency – Ability to work at high frequency – Good insulation capability – No windings, i.e. no magnetic fields � Disadvantages – Resonant device (frequency and load dependent) – Low Power – Cost 11

Prof. S. Ben-Yaakov, Power Electronics of Piezoelectric Elements, June 2006 [34] Piezoelectric Transformer Applications 1. Fluorescent lamp driver for laptop backlight (commercial) 2. Fluorescent lamp driver for LCD monitor (TV) backlight 3. Ionizer (commercial) 4. Fluorescent lamp ballast (high power) 5. Cell phone battery charger 6. Laptop battery charger 7. Isolated gate driver The main reason for commercial holdup: price Prof. S. Ben-Yaakov, Power Electronics of Piezoelectric Elements, June 2006 [35] Miscellaneous devices and applications • Welders • Ultrasonic Cleaners • Humidifiers • Nebulizers • Massage and skin scrubbers • Ozonator (high voltage) Prof. S. Ben-Yaakov, Power Electronics of Piezoelectric Elements, June 2006 [36] 2. Models of piezoelectric devices Modeling of Piezoelectric Elements devices Purpose: • Analytical derivations • Simulation Approach: • Mechanical-Electrical analogy • Equivalent circuit (based on Mason ’ s Model) 12

Prof. S. Ben-Yaakov, Power Electronics of Piezoelectric Elements, June 2006 [37] Electrical-Mechanical Relationships � TechOnLine - Piezoelectric Sidebar 2 Bridging the Mechanical and Electrical Worlds.htm Prof. S. Ben-Yaakov, Power Electronics of Piezoelectric Elements, June 2006 [38] Mechanical-Electrical Analogy c m r Mechanical Electronic System system m-mass L r-losses R C r R m L r c=1/stiffness C v-velocity i F-force u Prof. S. Ben-Yaakov, Power Electronics of Piezoelectric Elements, June 2006 [39] Electrical Coupling • Electrical connection by plated electrodes 13