Wireless Power Transfer System Design. Julius Saitz ANSYS

Transcription

1 Wireless Power Transfer System Design Julius Saitz ANSYS 1

2 WPT System 2

3 Wireless Power Transfer (WPT) Near-Field (Inductive coupling, resonant) Do not rely on propagating EM waves Operate at distances less than a wavelength of transmission signal Resonance obtained by use of external circuit capacitor Electric and magnetic fields can be solved separately Focus of this presentation Far-Field (resonant) Operating range to ~10 meters Self capacitance of coil turns are of importance Requires full wave solver with coupled electric and magnetic fields 3

4 Design Challenges Magnetic Analysis Inductance/Resistance calculations versus frequency Ensure linear mode operation Relative Position sensitivity study Loss evaluation Effect of temperature on magnetic performance Circuit Analysis Operate in resonant mode, considering magnetic results Compute efficiency considering relative position Transient simulation considering frequency dependent effects Wireless Power Transfer Thermal Management Consider local losses distribution in thermal evaluation Consider changing of electrical properties with temperature 4

5 Outline Large Gap Transformer Design Using Computational Electromagnetics Combination of Circuit and Magnetic Analysis for Resonance Thermal Management 5

6 Large Gap Transformer Design Using Computational Electromagnetics 6

7 Regular Transformer Low reluctance flux path is available Mutual Coupling between the coils can be easily determined using Magnetic Circuit approach Leakage flux can be considered to be negligible Mutual inductance can be derived using flux balance Analytical solution possible within permissible level of accuracy 7

8 Large Gap Transformer No Specific path for the magnetic flux Leakage flux is significant enough and can not be neglected Analytical methods are proposed for calculation of Mutual inductance using Maxwell s formula for two coaxial circular coils M = 2μ 0 R p R s k 1 k2 2 K k E k Application of these formulas to real life cases is almost impossible Computation Electromagnetics can help to reduce problem complexity significantly 8

9 Maxwell 9

10 V/m ANSOFT Transformers Lorentz Force Insulation Dielectric Withstand, Maximum E-field Inductance 4E+006 3E+006 Creep Stress Curves (V/m) xformer4 Curve Info Allowable Withstand C... Sorted_E_Tangent $PermOil='2.2' E_Tangent $PermOil='2.2' Cumulative_Stress $PermOil='1' 2E+006 Cumulative_Stress $PermOil='2.2' Cumulative_Stress $PermOil='6' 1E+006 0E+000 Losses and Temperature in Ferrite Core -1E Distance (m) Creep Stress Converters Load Analysis Foil Losses Tank Wall Losses Bus Bars 10

11 WPT Magnetic simulation Flow Chart Magnetic Field Solver + Circuit / System Simulator Magnetostatic Core, Winding Eddy Current (time harmonic) Impedance Model Gap Sliding Circuit / System Simulator (AC / TR) 11 Eddy Current Fields, Losses Circuit / Drive / Controller design Waveform, Efficiency, Power factor, Response

12 Magnetostatic Analysis Saturation Magnetic shielding Self and Mutual Inductance Coupling Coefficient M L2 L ANSYS, Inc. April 27, 2015

13 Parametric Analysis using Maxwell 13

14 Eddy Current (Frequency domain) Impedance vs frequency State Space Model for Circuit Analysis Losses Eddy current shielding Core(Power Ferrite) Shield Plate (Aluminum) 14

15 Combination of Circuit and Magnetic Analysis for Resonance 15

16 Inductive Type Coupling Near Field 1) Electromagnetic analysis to determine R, L, M C C Magnetic R, L, M R L M L R 2) Resonant circuit realized by a lumped capacitance parameter in the circuit simulator ANSYS, Inc. April 27, 2015

17 System Approach with Simplorer Secondary Coil Reduced Order Model (ROM) 17 Primary Coil

18 Frequency Domain Analysis: System Level 18

19 Parametric Analysis: Frequency Domain Bode Plot: Load Voltage vs Gap Gap Sliding Geometric parameters are Available in the circuit environment Bode Plot: Load Voltage vs Slide 19

20 Transient Analysis 20

21 Gap [mm] Efficiency[%] Efficiency Map Output/Input Power Tuned capacitance for each conditions P VI cos P P out in Efficiency[%] 100[%] Max.96% 50% 90% 20% 21 Sliding [mm] Gap [mm] Sliding [mm]

22 Optimize the Design: Various Shape Types Disk Coil type Solenoid Coil type 22

23 Efficiency as a function of sliding direction and distance Gap between coils kept constant ANSYS, Inc.

24 Gap Efficiency as a function of gap between coils Zero sliding ANSYS, Inc.

25 System Simulation WPT 3PHAS 3PHAS A * sin (2 * pi * f * t + PHI + phi_u) ~ ~ THREE_PHASE1 THREE_PHASE1 A * sin (2 * pi * f * t + PHI + phi_u) PHI = 0 PHI = 0 D5 D5 D7 D7 D9 D9 IGBT1 IGBT1 D1 D1 IGBT3 IGBT3 D3 D3 + + W W WM1 WM1 Cs Cs 1.93uF 1.93uF R1 R1 (1/ ) ohm (1/ ) ohm Current_1st_1:src Current_1st_1:src Current_1st_1:snk Current_1st_1:snk Current_2nd_1:src Current_2nd_1:src Current_2nd_1:snk Current_2nd_1:snk R2 R2 (1/ ) ohm (1/ ) ohm + + W W WM2 WM2 D11 D11 D13 D13 Rload Rload 10ohm 10ohm ~ ~ ~ ~ PHI = -120 PHI = -120 PHI = -240 PHI = -240 D6 D6 D8 D8 D10 D10 C1 1000uF C1 1000uF IGBT2 IGBT2 D2 D2 IGBT4 IGBT4 D4 D4 Current_1st_2:src Current_2nd_2:src Current_1st_2:src Current_2nd_2:src Current_2nd_2:snk Current_1st_2:snk Current_2nd_2:snk Current_1st_2:snk Cp 5.24uF Cp 5.24uF D12 D12 D14 D14 C2 C2 1e-006farad 1e-006farad Battery Battery AC200V 0 0 Rectify 0 0 STATE_11_1 STATE_11_1 TRANS1 TRANS1 Inverter STATE_11_2 STATE_11_2 TRANS2 TRANS Wireless Power Transformer Curve Info TR TR Curve Info TR TR Battery WM1.I WM1.I WM2.I WM2.I rms rms LBATT_A1 0 LBATT_A1 ICA: ICA: FML_INIT1 FML_INIT Y1 [A] Y1 [A] Modulation_Index:=0 Carrier_Freq:=10k Frequency:=10k Modulation_Index:=0 Carrier_Freq:=10k Frequency:=10k Dead_Time:=2u DC_Source:=200 Dead_Time:=2u DC_Source:=200 SINE1 SINE1 AMPL=Modulation_Index FREQ=Frequency AMPL=Modulation_Index FREQ=Frequency TRIANG1 TRIANG1 AMPL=1 FREQ=Carrier_Freq AMPL=1 FREQ=Carrier_Freq TRANS4 DT4 TRANS4 DT4 SET: TSV4:=1 SET: TSV3:=0 SET: TSV2:=0 SET: TSV1:=1 SET: TSV4:=1 SET: TSV3:=0 SET: TSV2:=0 SET: TSV1:=1 STATE_11_4 STATE_11_4 SINE1.VAL < TRIANG1.VAL SINE1.VAL < TRIANG1.VAL SET: TSV4:=0 SET: TSV3:=0 SINE1.VAL > TRIANG1.VAL SET: TSV2:=0 SET: TSV1:=0 DEL: DT4##Dead_Time SET: TSV4:=0 SET: TSV3:=0 SINE1.VAL > TRIANG1.VAL SET: TSV2:=0 SET: TSV1:=0 DEL: DT4##Dead_Time SET: TSV4:=0 SET: TSV3:=0 DT1 SET: TSV2:=0 SET: TSV1:=0 DEL: DT1##Dead_Time TRANS SET: TSV4:=0 SET: TSV3:=0 DT1 SET: TSV2:=0 SET: TSV1:=0 DEL: DT1##Dead_Time TRANS3 STATE_11_3 SET: TSV4:=0 SET: TSV3:=1 SET: TSV2:=1 SET: TSV1:= STATE_11_3 Controller SET: TSV4:=0 SET: TSV3:=1 SET: TSV2:=1 SET: TSV1:= TR TR TR TR TR Curve Info Y Axis rms TR TR TR Curve Info Y Axis rms WM1.I WM1.I WM2.I WM2.I WM1.V WM1.V WM2.V WM2.V Y Y Y Y Y Y Y Y Y2 [V] Y2 [V] Y1 [A] Y1 [V] Y1 [A] Y1 [V] Time [ms] Time [ms] TR TR Curve Info Curve Info TR TR WM1.V WM1.V WM2.V WM2.V rms rms Time [ms] Time [ms] MX1: MX2: MX1: MX2: Time [ms] Time [ms] 25

26 Thermal Management 26

27 Temperature in ANSYS Mechanical or CFD Ohmic Loss Temperature Core Loss 27

28 ICA: THREE_PHASE1 A * sin (2 * pi * f * t + PHI + phi_u) PHI = 0 PHI = -120 PHI = -240 SINE1 FML_INIT1 Modulation_Index:=0 Carrier_Freq:=20k Frequency:=20k Dead_Time:=2u DC_Source:=400 AMPL=Modulation_Index FREQ=Frequency TRIANG1 AMPL=1 FREQ=Carrier_Freq 0 D5 D6 0 TRANS4 DT4 D7 D8 D9 D10 STATE_11_1 SET: TSV4:=1 SET: TSV3:=0 SET: TSV2:=0 SET: TSV1:=1 STATE_11_4 C1 1000uF TRANS1 SINE1.VAL < TRIANG1.VAL SET: TSV4:=0 SET: TSV3:=0 SINE1.VAL > TRIANG1.VAL SET: TSV2:=0 SET: TSV1:=0 DEL: DT4##Dead_Time IGBT1 IGBT2 STATE_11_2 TRANS3 D1 D2 SET: TSV4:=0 SET: TSV3:=0 DT1 SET: TSV2:=0 SET: TSV1:=0 DEL: DT1##Dead_Time STATE_11_3 SET: TSV4:=0 SET: TSV3:=1 SET: TSV2:=1 SET: TSV1:=0 TRANS2 IGBT3 IGBT4 D3 D4 Curve Info Y Axis rms WM1.I WM2.I WM1.V WM2.V PWR_Probe1 PWR Probe PWR_Probe2 PWR Probe WM1 Cs 1.72uF R1 7.2mOhm Current_1:snk Current_2:snk R2 3.6mOhm Cp 4.96uF WM2 D11 D12 D13 D14 C2 1uF Curve Info WM1.V WM2.V Curve Info WM1.I WM2.I 0 rms rms Rload 13ohm Battery LBATT_A1 Summary ANSYS offers a comprehensive modeling solution for Wireless Power Transfer systems: Magnetostatic Frequency domain Circuit and system level Thermal 3PHAS ~ ~ ~ Y1 [V] + W Current_1:src Current_2:src + W TR TR Time [ms] Y1 [A] TR Y TR Y TR Y TR Y Y2 [V] Y1 [A] TR TR Time [ms] MX1: MX2: Time [ms] System Level Modeling Electromagnetic-Circuit Wireless Power Transfer Electromagnetics ANSYS, Inc. April 27, 2015