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EMC Modeling of IGBT Motor Controller. Missouri University of Science and Technology & Rose-Hulman Institute of Technology Departments of Electrical and Computer Engineering. RHIT Daniel Baker Andrew Gawlik Gareth Shields Chris Valenta Dr. Ed Wheeler. UMR Matt Halligan Igor Izyumin
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EMC Modeling of IGBT Motor Controller Missouri University of Science and Technology & Rose-Hulman Institute of Technology Departments of Electrical and Computer Engineering RHIT Daniel Baker Andrew Gawlik Gareth Shields Chris Valenta Dr. Ed Wheeler UMR Matt Halligan Igor Izyumin Clint Patton Jason Phillips Dr. Jim Drewniak
Last Week: Phase 1 ‘3L Model’ Last Week’s Model Note that C3 is shorted to ground.
IGBT Phase 1: Simulated Impedance vs. ‘3L Model’ Last Week’s Model
IGBT Phase 1: Measured Impedance vs. ‘3L Model’ Last Week’s Model
Analysis: Poles and Zeros of the ‘3L Model’ • Goal: To learn which circuit elements determine which poles and zeros. Last Week’s Model
Mathcad: Plotted ‘3L Model’ Transfer Function POLES ZEROS
Analysis Results Conclusions: The transfer function accurately represents the ‘3L’ model. The poles and zeros do not have a simple relationship based on the circuit elements.
Observed ‘Glitch’ First Phase Leg Re-Measured • Attempt to reproduce the ‘glitch’ at high frequencies. • Impedance zeros do not line up because of the changing probe inductance (L1).
New Ltot = 14.9 nH Old Ltot = 13.7 nH Comparison of Old vs. New Measurement
Lprobe CafA,LafA Lb2 CafG LafG Lb1 CafA,LafA New Geometry-based Phase 1 Model ‘M2’ Model
New Geometry-based Phase 1 Model • Uses simulated branch inductance values • Uses measured capacitance values ‘M2’ Model
Sum of Bridge Inductances Note: Both the 3L and the M2 model are based on measured capacitances and different simulated subsections of Phase Leg 1.
Possible Sources of Error • Need to use Simulated Capacitances • Transient vs. Frequency Solver? • CafG = 62 pF using frequency solver • CafG = 59 pF using transient solver • Accuracy Level • Lprobe = 3.7 nH @ 1e-9 • Lprobe = 4.36 nH @ 1e-12 • Simulation probe concentrates the current – adds unnecessary inductance to each branch inductance simulation? • Added inductance due to the narrow short to ground?
‘M2’ Model Bridge Inductances: Simulation Results
First Phase Leg: Lprobe Simulated Impedance Lprobe = 4.36 nH
First Phase Leg: LafA Simulated Impedance LafA = 2.33nH
First Phase Leg: Lb1 Simulated Impedance Lb1 = 3.76 nH
First Phase Leg: LafG Simulated Impedance LafG = 1.47nH
First Phase Leg: Lb2 Simulated Impedance Lb2 = 2.40 nH
First Phase Leg: LafI Simulated Impedance LafI = 3.83 nH
Phase 1 w/ Probe Inductance Simulation Calculated L: 15.0 nH -Probe adds 2.6 nH
First Phase Leg Preliminary Model • A preliminary model for the first phase leg was created. • Capacitances: Measured Area Fills A, G, and I. • Inductances: Selected to provide a rough match with the first pole and zero.
Phase 1 Model: Using Three Inductances • An unwanted resonance was found in the four inductance model. • L3 was replaced by the sum of L3 and L4. • L4 was set to zero.