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UMR IGBT Presentation

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UMR IGBT Presentation Powered By Docstoc
					        EMC Modeling of AC Drive
                           Chris Valenta

       Rose-Hulman Institute of Technology
                         &
   Missouri University of Science & Technology
Departments of Electrical and Computer Engineering
                                               MS&T
              RHIT                          Matt Halligan
           Daniel Baker                      Igor Izyumin
          Gareth Shields                      Clint Patton
           Chris Valenta                    Jason Phillips
          Dr. Ed Wheeler                   Dr. Jim Drewniak
The Problem

• Electromagnetic Interference (EMI) in AC motor drive
   – Fast switching currents in insulated gate bi-polar transistor (IGBT) module
   – PCB coupling paths to the cables and motor
• Causes device failure
• Meet government limits
• Costly to diagnose late in design cycle


               COUPLING
  IGBT           PATH
                                 Cables
Objectives
 • Create a circuit model (SPICE) of the EMI coupling paths in the drive including:
    – the IGBT package (L and C)
    – the cables and motor measurements and modeling
        • Shielded & unshielded cable
        • Ferrites
 • Document and demonstrate the processes involved for EMC design
 • Demonstrate mitigation opportunities for EMC design and discovery
IGBT Modeling
•Intended current paths
     •Shown in schematic
•Non-intended current paths
     •Parasitic values determined by
     device geometry
         •Capacitance
         •Inductance
IGBT Capacitance Modeling
•Area fill to heat sink
    •Parallel plate capacitor model
•Area fill to area fill
    •<10% of smallest area fill to heat sink
    capacitance
•Constructed regions in CST Microwave Studio
IGBT Measurement
                                            Region I Impedance
              200

              150
   |Z| (dB)




              100

               50           RHIT
                            UMR
                0
                        2               4               6          8
                       10              10            10           10
                                             Frequency (Hz)

              200
                            RHIT
              100           UMR
<Z (o)




                0

              -100

              -200
                   0               2          4               6        8    10
                 10           10            10           10       10       10
                                             Frequency (Hz)



                                                    C = 39.4 pF
IGBT Capacitance Modeling
 •Measurements consistent with simulations
 •Error caused by additional parasitics to other regions




  Region      Measured (pF)          Simulated (pF)        % Difference
  B           37.7                   38.8                  2.9
  G           53.3                   57.3                  7.2
  I           39.4                   45.1                  13.7
IGBT Inductance Modeling
• Phase leg loop total inductance values desired
• Simulation results to be placed in equivalent circuit
IGBT Inductance Measurement




                 L=13.3nH
IGBT Inductance Simulation
IGBT Inductance Simulation and Verification
                                                   Measured vs. Simulated Impedance of IGBT Phase Leg 1
                                      80
Simulated                             60
                                              Measured Impedance
                    Impedance (dB)


13.1nH                                40      Simulated Impedance

                                      20
Measured
                                       0
13.3nH                                -20

                                      -40
                                          6                7                                    8          9
                                        10               10                                  10           10
                                                                     Frequency (Hz)


                                     100


                                      50
            Phase(degrees)




                                       0


                                      -50


                                     -100
                                          6                7                                    8          9
                                        10               10                                  10           10
                                                                     Frequency (Hz)
IGBT Partial Inductance
                Probe wire (Lprobe)                 3.2 nH

                Area fill A (CafA ,LafA)            35.4 pF, 2.50 nH

                Bond wires (A to G) (Lb1)           4.11 nH

                Area fill G (CafG ,LafG)            58.7 pF, 1.62 nH

                Bond wires (G to I) (Lb2)           2.6 nH

                Area fill I (CafI ,LafI)            45.4 pF, 4.04 nH



                 Lprobe    CafA,LafA         CafG             Lb2

                                             LafG
                                       Lb1


                                                                    CafI,LafI
IGBT Partial Inductance
Motor and Cable Measurements
•Built test setup for measurements
    •Impedance Analyzer
    •Network Analyzer
    •Time Domain Reflectometer (TDR)
•Determine transmission line model of cable
•Create high frequency model of motor
•Characterize effectiveness of ferrites
Cable Measurements


                       Z C  263 
                       Z M  234 
                     %Error  11.0%

                      l  0.877H / m
                       c  12.7 pF/m
Motor Model
•Initially modeled motor as capacitor
     •Poor data fit
•Used high frequency model from Schinkel et. al.
     •Took common and differential mode measurements
Motor Model
Ferrites - Measurements
References
Mohan, Undeland, and Robbins, Power Electronics: Converters, Applications
and Design, New York: Wiley, 1989.

Pak, T.T., “EMI Investigation of a Hybrid Electric Vehicle Traction Drive.”
Masters Thesis, University of Missouri-Rolla, 2000.

Schinkel, M., Guttowski, S., and John, W., “Efficient HF Modeling and Model
Parameterization of Induction Machines for Time and Frequency Domain
Simulations,” Applied Power Electronics Conference and Exposition, 2006.
APEC ‘06. Twenty-First Annual IEEE, pp. 6, Mar. 2006.
Questions?
    Christopher Valenta – christopher.r.valenta@rose-hulman.edu
           Daniel Baker – daniel.baker@rose-hulman.edu
         Gareth Shields – gareth.shields@rose-hulman.edu
            Dr. Ed Wheeler –wheeler@rose-hulman.edu

				
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posted:8/29/2012
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