the analysis of qi wireless power transfer system for power … · · 2017-03-13the analysis of...

1 © 2015 ANSYS, Inc. October 14, 2016 ANSYS Confidential

The Analysis of Qi Wireless Power Transfer System for Power Class 0 Specification

삼성전기

하근수, Ph.D./수석연구원


Contents

• Introduction to Wireless Power Transfer System

• Electromagnetic Analysis − Magnetostatic Analysis

− Combined Magnetostatic & AC Analysis

• Integrated System Analysis− Verification

− Resonance Circuit

− Total Circuit


Introduction to Wireless Power Transfer System

• 무선충전의정의− 전원공급선을제거,무선으로전력을전송

• 무선충전시스템방식− 자기유도 (Magnetic Inductive Coupling)

• 근거리 (~5mm) / Single Device 충전

− 자기공진 (Magnetic Resonance Coupling)

• 원거리 (~50mm) / Multi Device 충전

• 주요제어기술− 충전폐루프제어 (Closed Loop Control)

− 이물질감지 (Foreign Object Detection)

− 충전상태제어 (State Control)


Introduction to Wireless Power Transfer System

• Power Class 0− WPC designation for flat-surface devices, such as chargers, mobile phones, tablets, cameras,

and battery packs, in the Baseline Power Profile (≤5W) and Extended Power Profile (≤15W)

• Baseline Power Profile− The minimum set of features applying to Power Transmitters and Power Receivers that can

transfer no more than around 5W of Power

• Extended Power Profile− The minimum set of features applying to Power Transmitters and Power Receivers that can

transfer power above 5W

※ Ref.: The Qi Wireless Power Transfer System Power Class o Specification Version 1.2.1 October 2015


Target _ Specifications

• Transmitter

− Lp = 24±10%[uH] , Cp = 100 ±10%[nF]

− Vin = 12±5%[V] , fop = 110 … 205 [kHz]

• Receiver

− Ls = 15.3±1[uH] , C = 20[uF]

− Cs = 127 ±1%[nF] , Cd = 1.6±5%[nF]

※ Ref.: Section 3.2.30 [Low Power_V1.2, part1] ※ Ref.: Section A.1 [Low Power_V1.2, part1]

A30 Coil Example Rx1 Coil


Electromagnetic Analysis _ Magnetostatic Analysis

• Results− Self Inductance : 25.738[uH]

규격에서정의한 Lp의범위(24±10% [uH]) 안에만족함.

− Magnetic Flux Density(左) / Field Strength(右)

• Transmitter Coil Model (A30 Coil)

− Bulk Model, not Detailed Coil as Litz Wire


Electromagnetic Analysis _ Magnetostatic Analysis

• Results− Self Inductance : 15.994[uH]

규격에서정의한 Ls의범위(15.3±1 [uH]) 안에만족함.

− Magnetic Flux Density(左) / Field Strength(右)

• Receiver Coil Model (Example Rx1 Coil)

− Bulk Model, not Detailed Coil as Litz Wire


Electromagnetic Analysis _ Combined Magnetostatic & AC Analysis

• Results

− Coupling Coefficient(左) / Inductance(右)

Gap의증가에따라감소함을확인.

− Magnetic Flux Density(左) & Field Strength(右)

• Magentostatic_Parametric Sweep

− Coil-to-Coil Gap0 (default): 5[mm]

− Gap: 2.5 … 10[mm], 1.5[mm] step

Distance = Gap0 + Gap

7.5[mm]15[mm] 7.5[mm]15[mm]


Electromagnetic Analysis _ Combined Magnetostatic & AC Analysis

• Results− Coupling Coefficient

− Inductance (左) / Resistance (右)

거의일정 주파수↑ ∝ Resistance ↑

• Eddy Current

− AC 주파수가변: 110 … 205[kHz], 5[kHz] Step

− Shield Plate 포함 (for Safety)− Skin Effect 영향, 도체표면만Magnetic Field 형성

(Perfect conductor 재질, Impedance Boundary Setup)

거의일정


Appendix. Skin Depth

• 고주파 AC 인가에따른전자계필드해석의경우: − 일반적으로 Skin effect 영향으로도체표면에서만Magnetic Field가형성

− 이로인한 Skin depth는매우작아해석의어려움이존재

(즉, 매우조밀한Mesh 형성→ Mesh 수급증→ 계산시간급증)

− 다음의조건이만족할경우, 도체의내부에서의계산은하지않고,

도체의경계면만계산할수있다. (예: Impedance Boundary Setup)

※조건: Rule of Thumb (ANSYS recommendation)

도체의 Skin depth(δ)가도체두께의 1/10이하일경우, Impedance Boundary는효과적이다.


Integrated System Analysis _ Verification

• Results (Comparisons)− Inductance

− Resistance

• Import Maxwell Model to Simplorer − Add Maxwell Dynamic Eddy Current Model

− Imported Model 검증회로구성

0 0

R1

1GOhm

R2

1GOhm

I1

1A

+

V

VM1

A

AM1

Current1:src Current2:src

Current1:snk Current2:snk

Resistance = Re(VM1.V) , Inductance = Im(VM1.V)/(2*pi*F) 해석결과매우유사→ Circuit Analysis 가능


Integrated System Analysis _ Resonance Circuit

• Results − Frequency vs. Voltage Gain

− Frequency vs. Efficiency

• Resonance Characteristics − AC Sweep: 50 … 250 [kHz], 5[kHz] step

공진주파수: 95[kHz] @ Coil-to-Coil 거리=7.5[mm]0 0

E1

12V

W

+

WM1

Rp_dc

75.92mOhm

Cp

100nF

Rs_dc

218mOhm

Cs

127nF

Cd

1.6nF

RL

10ohm

W

+

WM2

Current1:src Current2:src

Current1:snk Current2:snk

Vin = 12[V]DC Resistance = 75.92[mΩ]Cp = 100[nF]

RL = 10[Ω]DC Resistance = 218[mΩ]Cs = 127[nF] , Cd = 1.6[nF]

91% ↑ @ 동작주파수 , 93% @ 140[kHz]


Integrated System Analysis _ Total Circuit

• Inverter-Resonance-Rectifier Characteristics− PWM Freq. Sweep: 110…205[kHz], 5[kHz] step

0 0

E1

12V

W

+

WM1

Rp_dc

75.92mOhm

Cp

100nF

Rs_dc

218mOhm

Cs

127nF

Cd

1.6nF

RL

10ohm

W

+

WM2

MOS1

G1

MOS2

G2

MOS3

G3

MOS4

G4

W

+

WM3

W

+

WM4

D1 D2

D3 D4

Cin

20uF

Cout

20uF

D5 D6

D7 D8

SET: G1:=LOSET: G3:=HI

SET: G1:=HISET: G3:=LO

TRANS1

TRIANG1.VAL < DUTY_L

TRANS2

TRIANG1.VAL>=DUTY_L

TRIANG1

PHASE=0deg

AMPL=HI/2

FREQ=PWM_Frq

OFF=HI/2

ICA:

FML_INIT1

DUTY_L:=0.5DUTY_R:=0.5HI:=1LO:=0PWM_Frq:=PWM_FPhaseShift:=0

TRANS3

TRIANG2.VAL>=DUTY_R

TRANS4

TRIANG2.VAL < DUTY_R

SET: G2:=LOSET: G4:=HI

SET: G2:=HISET: G4:=LO

TRIANG2

OFF=HI/2PHASE=PhaseShiftAMPL=HI/2FREQ=PWM_Frq

PWR

Probe

PWR_Probe1

PWR

Probe

PWR_Probe2



• Full Bridge Inverter-Resonance-Rectifier Characteristics

0

E1

12V

W

+

WM1

Rp_dc

75.92mOhm

Cp

100nF

MOS1

G1

MOS2

G2

MOS3

G3

MOS4

G4

W

+

WM3

Cin

20uF

D5 D6

D7 D8

TRANS1


TRANS4




• Full Bridge Inverter-Resonance-Full Bridge Rectifier Characteristics

0

Rs_dc

218mOhm

Cs

127nF

Cd

1.6nF

RL

10ohm

W

+

WM2

W

+

WM4

D1 D2

D3 D4

Cout

20uF



• PWM Characteristics

Phase Shift Available

0

SET: G1:=LO

SET: G3:=HI

SET: G1:=HI

SET: G3:=LO

TRANS1


TRANS2

TRIANG1.VAL>=DUTY_L

TRIANG1

PHASE=0deg

AMPL=HI/2

FREQ=PWM_Frq

OFF=HI/2

ICA:

FML_INIT1

DUTY_L:=0.5DUTY_R:=0.5

HI:=1LO:=0

PWM_Frq:=PWM_FPhaseShift:=0

TRANS3

TRIANG2.VAL>=DUTY_R

TRANS4


SET: G2:=LO

SET: G4:=HI

SET: G2:=HI

SET: G4:=LO

TRIANG2

OFF=HI/2

PHASE=PhaseShiftAMPL=HI/2

FREQ=PWM_Frq

PWR

Probe

PWR_Probe1

PWR

Probe

PWR_Probe20

E1

12V

W

+

WM1

Rp_dc

75.92mOhm

Cp

100nF

MOS1

G1

MOS2

G2

MOS3

G3

MOS4

G4

W

+

WM3

Cin

20uF

D5 D6

D7 D8

TRANS1


TRANS4



Appendix. PWM Results

• Phase Shift(φ)=0 • Phase Shift(φ)=90˚φ



• Results− Frequency vs.. Voltage Gain(Load/DC Input)

PWM 동작주파수↑ ∝ Voltage Gain ↓



• Results− Frequency vs.. Load Voltage

PWM 동작주파수↑ ∝ Load Voltage ↓



• Results− Frequency vs.. Efficiency

PWM 동작주파수↑ ∝ Efficiency ↓ , (η = 67 ~ 36%)


감사합니다.

the analysis of qi wireless power transfer system for power … · · 2017-03-13the analysis of...

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