BÁO CÁO NGHIÊN CỨU VỀ BỘ CHUYỂN ĐỔI MA TRẬN TẦN SỐ CAO (High Frequency Matrix Converter) bao gồm các nội dung chính: 1. Background information. 2. Proposed converter. 3. Results todate. 4. Conclusion.
The University of Sheffield Electrical Machines & Drives Research Group 1 High Frequency Matrix Converter High Frequency Matrix Converter Nam Nguyen-Quang eBook for You The University of Sheffield Electrical Machines & Drives Research Group 2 • Background information • Proposed converter • Results to-date • Conclusion OVERVIEW eBook for You The University of Sheffield Electrical Machines & Drives Research Group 3 • Induction Heating (IH) Î Basic Principles Î Resonant Tanks • Conventional Converters for IH Î Current Source Inverter (CSI) Î Voltage Source Inverter (VSI) BACKGROUND INFORMATION eBook for You The University of Sheffield Electrical Machines & Drives Research Group 4 • A coil (work-head) creates a magnetic field, which induces a current in a conductor (work-piece) • Large current is required Ö the use of resonant tanks • Loose coupling between the work-head and the work-piece Ö high quality factor INDUCTION HEATING – BASIC PRINCIPLES eBook for You The University of Sheffield Electrical Machines & Drives Research Group 5 • Skin depth: the depth from surface, at which the current density is about 1/3 of its surface value. • Skin depth decreases when frequency increases. • Frequency bands have been defined for IH: Î Supply-frequency: 50 – 540 Hz Î Medium frequency: 500 Hz – 50 kHz Î Radio frequency: 50 kHz – 10 MHz Î Microwave: 10 MHz upwards INDUCTION HEATING – BASIC PRINCIPLES eBook for You The University of Sheffield Electrical Machines & Drives Research Group 6 INDUCTION HEATING – RESONANT TANKS Series resonant tank • High impedance at high frequency • Used with VSIs Parallel resonant tank • Low impedance at high frequency • Used with CSIs C L R C L R eBook for You The University of Sheffield Electrical Machines & Drives Research Group 7 • Higher order resonant tanks have been used • Most widely reported and useful is the LLC tank INDUCTION HEATING – RESONANT TANKS C L 2 R L 1 Î High impedance at high frequency, can be used with VSIs Î Large current can circulate through C and L 2 eBook for You The University of Sheffield Electrical Machines & Drives Research Group 8 • First widely used topology • Run at the resonant frequency • Power is only controlled by amplitude modulation CONVENTIONAL CONVERTERS – CSI C L RI eBook for You The University of Sheffield Electrical Machines & Drives Research Group 9 • Two utility supply interfaces CONVENTIONAL CONVERTERS – CSI Low Power High Power eBook for You The University of Sheffield Electrical Machines & Drives Research Group 10 • Advantages Î Low reactive power flow Î Constant operating frequency • Disadvantages Î Effect of stray inductance: limit on frequency, and physical cable length Î High switching losses Î Non-unity power factor, high harmonic distortion CONVENTIONAL CONVERTERS – CSI eBook for You [...]... Inverter eBook for You converter R LLC Resonant Tank The University of Sheffield Electrical Machines & Drives Research Group PROPOSED CONVERTER 18 • Single-phase to single-phase matrix converter • Three-phase to single-phase matrix converter (Three phase MC) Topology Problems The University of Sheffield Electrical Machines & Drives Research Group eBook for You (Single phase MC) Topology Problems SINGLE... Disadvantages eBook for You Many power control methods, some with ZVS or ZCS, stray capacitances can be utilised Stray inductances can be utilised Large current harmonics at line side, non-unity power factor Bulky and unreliable DC link capacitor The University of Sheffield Electrical Machines & Drives Research Group CONVENTIONAL CONVERTERS – VSI 17 • Basis for single phase high frequency matrix L1 L2 V C Source... (μs) The University of Sheffield Electrical Machines & Drives Research Group CONVENTIONAL CONVERTERS – VSI 13 • Amplitude modulation eBook for You Varying the DC link voltage Operating just above the resonant frequency The University of Sheffield Electrical Machines & Drives Research Group CONVENTIONAL CONVERTERS – VSI 14 • Phase angle (phase-shift) modulation: Many S2 0 1 2 3 4 5 6 7 8 9 20 Current Voltage... interface: Small line filter • Power control: PWM with soft switching The University of Sheffield Electrical Machines & Drives Research Group eBook for You commutation THREE PHASE MC – TOPOLOGY 22 eBook for You • Topology VA VB VC The University of Sheffield Electrical Machines & Drives Research Group THREE PHASE MC – PROBLEMS 23 • Commutation problem: directly applying • Utility supply inferface: small line... (kHz) Power angle (deg.) Input current vs frequency Input current vs power angle The University of Sheffield Electrical Machines & Drives Research Group RESULTS – REFERENCE SYSTEM 31 • Output current characteristics (Vin = 115 VDC) 7.5 7 7 6.5 6 5.5 Measured SPICE SABER 70 deg 90 deg 110 deg 5 4.5 4 150 155 160 165 170 175 180 185 Frequency (kHz) Output current vs frequency 6.5 eBook for You Output current... control with soft switching is preferrable The University of Sheffield Electrical Machines & Drives Research Group eBook for You switching pattern of single-phase version may create large distortion in input currents RESULTS TO-DATE 24 • Literature survey • Simulations of single phase MC The University of Sheffield Electrical Machines & Drives Research Group eBook for You • Reference system RESULTS – LITERATURE... University of Sheffield Electrical Machines & Drives Research Group eBook for You • • • • • 25 RESULTS – REFERENCE SYSTEM 26 • Specifications: 2.5 kW, 125 – 250 kHz eBook for You Input Voltage Rectifier DC Link H-bridge Inverter The University of Sheffield Electrical Machines & Drives Research Group Resonant Tank RESULTS – REFERENCE SYSTEM 27 • System diagram Gate Drive Frequency, PWM Angle H-bridge Inverter...CONVENTIONAL CONVERTERS – VSI 11 • More emergent technology • Power can be controlled by frequency, amplitude, C V The University of Sheffield Electrical Machines & Drives Research Group L eBook for You or phase angle (phase-shift) modulation R CONVENTIONAL CONVERTERS – VSI 12 • Frequency modulation S4 S3 S2 S1 Output voltage and current eBook for You Gate signals The simplest and most... Electrical Machines & Drives Research Group RESULTS – SIMULATION OF SINGLE PHASE MC 32 eBook for You • Topology VA VB The University of Sheffield Electrical Machines & Drives Research Group RESULTS – SIMULATION OF SINGLE PHASE MC 33 15 10 I in V 5 in 0 -5 -10 -15 0 2 4 6 8 0 2 4 6 8 10 12 14 16 18 20 10 12 14 16 18 20 Output current (A) 40 20 0 -20 -40 Time (ms) The University of Sheffield Electrical Machines... current (A) 20 0 -10 -20 -30 -40 0 5 10 15 20 25 30 35 40 45 Time (μs) The University of Sheffield Electrical Machines & Drives Research Group 50 CONCLUSION 35 • Proposed converter • Results to-date The University of Sheffield Electrical Machines & Drives Research Group eBook for You • Background information . University of Sheffield Electrical Machines & Drives Research Group 1 High Frequency Matrix Converter High Frequency Matrix Converter Nam Nguyen-Quang eBook for You The University of Sheffield Electrical. snubbers CONVENTIONAL CONVERTERS – VSI 0 1 2 3 4 5 6 7 8 9 10 S1 S2 S3 S4 Gate signals 0 1 2 3 4 5 6 7 8 9 10 -30 -20 -10 0 10 20 30 Time ( μ s) Output voltage and current Current Voltage 0 1 2 3 4 5 6 7. capacitor CONVENTIONAL CONVERTERS – VSI eBook for You The University of Sheffield Electrical Machines & Drives Research Group 17 • Basis for single phase high frequency matrix converter CONVENTIONAL CONVERTERS