[信息与通信]Magnetics-training-Basic.ppt

DPEC - Chen Wei * Basic of High-frequency Magnetics in SMPS Contents Introduction Basic Magnetic theory Magnetics core material Magnetics winding loss Transformer winding Inductor winding Magnetics development SR DMC D2A CMC PFC L L TX Magnetics: Important in Power Electronics Magnetics are critical for: Size and weight Form factor Power loss Manufacture cost Temperature rise Performance EMI, RFI, Cross-regulation, Acoustic noise, Control, etc Power converter INPUT OUTPUT The Role of the Magnetics Magnetics Transformer Inductor Electrical isolation Voltage transform Current sensing Voltage sensing Energy transfer Current filter Energy storage Spike suppress Resonant Mag-amp Core Winding Shape Material Type Structure Size EMI Thermal Cost Freq. Power Bs m Loss Solid Litz Foil Stacked Sandwiched Interleaved Consideration Items in Magnetics Design Gauge Diameter Strain # Thickness Form factor Manufacture Mechanical Cost Safety Thermal dissipation EMC VICOR 2nd Generation DC/DC Converter Input inductor Input capacitor Main switch Main transformer Brain (Primary) Brain (Secondary) Resonant capacitor Output rectifier Output inductor Output capacitor a b c d e f g h i j VICOR 2nd generation high power density DC/DC converter Transformer power density: up to 1000W /in3 @ 30℃ temperature rise Module Power density: 100W/in3 (4.6“(117) x 2.2“(56) x 0.5(13) Up to 600W) Pricing: $0.38 per watt Vin= 300V, Vout=?V Basic Magnetic Theory Basic Electromagnetic Field Theory Ampere’s Law Faraday’s Law Flux Continuity Maxwell Equations Differential forms Integral forms Physical Laws Ampere’s Law: Currents in a winding Magnetomotive force Magnetic field Faraday’s Law: Voltage induced in a winding Total flux passing through interior of the winding Basic Magnetic Circuit Theory Faraday’s Law Flux Continuity F F1 F2 i i u F Ampere’s Law i1 i2 H: Magnetic field strength B: Magnetic flux density F: Magnetic flux ?: Magnetic flux linkage --- For squar