Zero power magnetic levitation using composite of magnetostrictive - piezoelectric ma
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 seminar class Active In SP Posts: 5,361 Joined: Feb 2011 02-03-2011, 03:34 PM presented by: NIVEETH C   niveeth.pptx (Size: 1.5 MB / Downloads: 58) Zero power magnetic levitation using composite of magnetostrictive - piezoelectric materials overview Introduction What is a composite? • Composite for magnetic force control • comparison • Experiments using composite only using composite and electromagnet Magnetic levitation • Inverse magnetostrictive effect • Joule loss • Zero power consumption during stationary • Control by the integral feedback • What is a composite? • Composite for magnetic force control • Dimensions Working… • When voltage is increased with fixed gap,flux changes as in (b) • Now the PZTs extends and reduces the compressive force on Terfenol-D • Thus magnetic force increases • Since flux is conserved increase of flux in terfenol cause decrease in the gap • COMPARISON OF ELECTROMAGNET WITH COMPOSITE ELECTROMAGNET • It consists of coil with large no of turns of winding requires large power supply with high voltage. • The operation is accompanied with joule loss • Even when equipped with permanent magnet,the zero power is only valid at equilibrium state. COMPOSITE • It does not require large power supply because stack PZTs provide maximum performance at rating voltage. • Power supply should amplify the voltage,but does not have to be capable of providing large current. • The composite does not consume electric energy in static operation at any value of force.This is due to capacitive property of PZTs. • Levitation using composite • Yoke equations • F = Fo + dF= Fo + Kx *x +Kv*v Kx-gradient of F with gap under fixed voltage Kv-gradient of F with voltage under fixed gap • Kinetic equation mx·· +cx· +Kx*x +Kv*v =0 c-damping coefficient • Combination of composite and electromagnet Experimental set up Working • Control voltage is fed to PZTs from gap sensor through dc-dc converter • To electromagnet through current amplifier • Converter is energized with a dry cell of 4.5v By varying the gap stationary under the fixed mass, the control outputs for electromagnet and composite are ic = Kpc *x + Kdc*x·+ Kic∫ic dt vp= Kpp*x + Kip ∫x dt • conclusion • Experiments on levitation was conducted and the gap at the levitation was successfully controlled by the voltage of the PZTs • It maintained zero power consumption in static state • Composite can be used for large loads too • Applications include high precision positioning and convey system • reference • T. Ueno, J. Qiu, and J. Tani, “Magnetic force control based on the inverse magnetostrictive effect,” IEEE Trans. Magn., vol. 40, no. 3, pp.1601–1605, May 2004. • T. Ueno, J. Qiu, and J. Tani, “New magnetic force control device with composite of giant magnetostrictive and piezoelectric materials,” IEEE Trans. Magn., vol. 39, no. 6, pp. 3534–3540, Nov. 2003. • T. Ueno and T. Higuchi, “Design of magnetostrictive/piezoelectric laminate composite for coil-less magnetic force,” IEEE Trans. Magn. vol. 41, no. 4, pp. 1233–1237, Apr. 2005. • T. Ueno and T. Higuchi, “Zero-power magnetic levitation by magnetic force control device using lamination of magnetostrictive material and piezoelectric material,” in Ninth Int. Symp. Magnetic Bearings, 2004.