Download Inductive Power Transfer

Innovative Technology Series
Workshop 6
Inductive Power Transfer
Presenter：
Dr Siu-Chung Wong
Department of Electronics and Information Engineering
The Hong Kong Polytechnic University
1
Part 1：Introduction
5. Control
6. Design Example
4. Transformer
1. Introduction
3. Compensation
Network
2. Basic Analysis
2
Introduction
Electric Power Transfer
Conventional method：
• Metal Conductor Soldering
• Electrical Plug and Socket
Potentially not
safe！
• Brush Metal Contact
3
Introduction
Conventional
Wireless
4
Roadmap of WPT
2010 commercialized
First
patent
Faraday，
Law of induction
1831
1891
Tesla Coil
1894
H. J. G. Bolger, F. A. Kirsten
and L.S. Ng, “Inductive
power coupling for an
electric highway system,”
Vehicular Technology
Conference, Vol.
28, pp.137-144, March 1978
1978
1964，
1968
Micro wave
WPT
1990s
1996-EV1，
1987—
SHARP
SAE J1773
microwave
HF IPT
airplane
1989-1996 charging of
EV
USA PATH
1980s
A4WP & PMA
merge
MIT, lighten a 60
W lamp 2 m
WPC wireless
away
charging
standard Qi
2010
2007
2008
WPC
established
2013
2015
2014
SAE “J2954” for
EV/PHEV
t(year)
IEC61580
Communication
standard for EV
1987—
implant
1980—Brush
replacement
5
WPT classification
Inductiveinductive and resonant
Capacitive
Can penetrate
metal, very short
distance, high
frequency and
lower power
Inductive—
Lower frequency，wider power
Long Range —
Laser/Microwave
Long or very long
distance
Resonant—
Higher frequency, longer distance
6
Capacitive coupling
Input voltage: 340V
Output voltage: 196V
Output current: 5.21A
Frequency: 540KHz
Efficiency: 83%
Air gap: 100um
Wireless Electric Vehicle Charging via Capacitive Power Transfer Through a Conformal
Bumper
Jiejian Dai , Daniel C. Ludois , APEC 2015
7
WPT – Long Range
—— Safety issue
—— Occupy a lot of space
—— higher loss
8
WPT Inductive Power Transfer
Japan
Airplane
IPT
Mojo Mobility
coils
I
P
T
Germany Wampfler WiPower
track IPT
Splashpower
2000
……
0.5W
Seiko
IPT charger
2007
Powermat
Japan
Haneda
Airport
Bus
IPT
东光
Seiko
2.5 W
IPT
2008
IPT
Fulton Innovation
IPT
2009
2010
Now
9
WPT Inductive Power Transfer
Magnetic Resonant
WPT
海尔“ 无尾” 电视
USA
MIT
Intel
Japan WPT
2007
2008
2009
2010
Sony
WPT
Now
 Less sensitive to transformer misalignment
 Safety Issue
 High frequency operation
10
WPT application
Industry
Cardiac Pacemaker
Artificial Heart
Medical
Home
EV charger
11
WPT application
3M—under
ground
positioning
0.6m-2m
HV
Reflect
Transmit
IoT power
Underground pipe dection
Nina M. Roscoe and Martin D. Judd. Harvesting Energy from Magnetic Fields to Power Condition Monitoring Sensors[J]. Sensors Journal, IEEE ,2013:3
12
WPT standards
Qi
First international IPT standard；
Established from City University Hong Kong
then the WPC （wireless power consortium)。
on Sept. 2015，WPC has 217 member。
Google“Nexus”and Nokia“Lumia”support
this standard。
13
Corporations
PMA(Power Matters Alliance)
Rezence (A4WP)
merged
Initialized by Duracell Powermat；
on Sept. 2015, A4WP has 150 members including Qualcomm，Samsung，Broadcom and Intel.
Duracell Powermat WiCC card
14
EV charging technology
Waseda
University Japan
KIST, Korea
ZTE, China
Gap：10cm
Gap：26cm
Gap：20cm
Power：30kW
Power：5*20kW
Power：30kW
Efficiency：92%
Efficiency：
80%~85%
Efficiency：92%
Announced：
2011
Announced：2013
Announced：2014
15
EV charging technology
Idaho National
Laboratory, USA
Qualcomm
Gap：11cm
Gap：
Power：3.3kW
Power：7.2kW
Efficiency：89.2%
Charging Time：1
hour
Announced：
2013
Announced：2015
Witricity
Operating
frequency：85kHz
Power：2kW
Charging Time：
1.5 hours
Announced：2014
16
Installation
ABB（Geneve Airport and Palexpo convention center），15
second charging at 400 kW，from top of the bus.
17
Wireless Power Transfer System
Primary
M
Secondary
VO
~
Inverter
Rectifier
Secondary
Feedback
circuit
Controller
F/V
pack
Gap
Driver
Circuit
converter
Battery
...
PFC
Single or
Circuit
Three phase
Filter
buffer
I
T
V
VCO
18
Critical Technology
Electromagnetic
compatibility
A
Communicatio
n
Material
G
B
WPT
Technology
F
Safety
E
Transformer
Coupling
C
D
Control
Circuit Theory and
Power Electronics
19
Critical Technology
IPT system
Primary
Primary
~
Inverter
Feedback
circuit
F/V
Large parameter variation
pack
I
T
Secondary
Filter
converter
Small Coupling Coefficient
Battery
Gap
Controller
Secondary
VO
Rectifier
Driver
Circuit
Gap
Secondary
...
PFC
Single or Circuit
Three phase
M
buffer
V
VCO
Tactic：
Inductances compensation
Optimization of Transformer
Effective control
20
Part 2：Basic Analysis
6. Design Example
1. Introduction
5. Control
2. Basic Analysis
4. Transformer
3. Compensation
Network
21
Transformer Model
Primary
~
Inverter
Transformer model
Battery
pack
I
T
Gap
Secondary
Feedback
circuit
Controller
F/V
VO
Rectifier
Driver
Circuit
converter
Secondary
...
PFC
Single or Circuit
Three phase
M
Filter
buffer
VCO
V
Coupling
22
Transformer Equivalent Model
Leakage inductance
model
n: Turns ratio
Three parameter model
Coupling Model
Equivalent n
L'L
L''L
*
*
1: n'
L'M


 LP  LL1  LM

2
 LS  LL 2  n LM

k
 M 

LP LS
 ' L
n  S
M

 '
LL1 LS  LM LL 2 LP LS  M 2

 LL 
L
LS
S


M2
'
 LM 
LS

1: n''
L''M
 '' M
n  L
P

 ''
M2
 LL  LS 
LP

 L''  L
P
 M

23
Part 3：Compensation network
1. Introduction
2. Basic Analysis
6. Design Example
3. Compensation
Network
5. Control
4. Transformer
24
Why compensation?
Primary Windings
Gap
Large leakage inductance and small
mutual inductance
Secondary Windings
 Improve input power factor
 Reduce device rating
 Improve power transfer
 Improve efficiency
 Reduce sensitivity to transformer parameter variation
25
Circuit
Power source
Inverter
Primary
 Voltage source input
 Current source input
Compensation
Rectifier
Filter
Load
Secondary
 C Filter
 LC Filter
26
Primary circuit
Voltage source input
vAB +
Capacitor
clamped
Current source input
Capacitor
clamped
27
Secondary Circuit
C filter，output voltage
assumed constant
LC filter，output current
assumed constant
RE
Phase of
vOR and iare
identical，like a resistor。
2
Equivalent load resistor：
4
Vo sin(t )
4
Vo
vOS 
8 V
8

RE 


 2 o  2 RL

i2
I 2 sin(t )
I  I 
2
28
OUTPUT EQUIVALENT
RESISTANCE
C filter，output voltage
assumed constant
LC filter，output current
assumed constant
RE
RE 
8
2
RL
RE 
2
8
RL
29
System Simplification
Square
voltage
Square
current
30
Resonant Compensation
Series
resonant
Voltage across L C compensated to zero。When
high Q，voltages across L and C can be higher
than the input。
Q
Parallel
resonant
L
R

1 L
R C
Current flow through L and C cancelled out。
31
Secondary Capacitor
Compensation
Parallel
Reflected Zr：
Series
Zr 
Power transfer capability：

1
LS CS
Compensation
Series
Parallel
2 M 2
Primary current： I P 
ZS
V AB
j L P  Z r
P  I P2  Re  Z r 
Re(Zr)
Im(Zr)
Comment
0
Im(Zr)=0
M 2
Capacitive load
independent Im(Zr)
 2M 2
RE
M 2 RE
L2S

LS
32
Secondary Capacitor
Compensation
Parallel
Series
If Ip constant
iS LS
jωMIP
Output current is load
independent
C i2
+
−
vOS
RE
Output voltage is load
independent
Can have load independent output.
33
Primary Capacitor
Compensation
Series
Parallel
and for driving high winding
Suitable
Suitable for driving large value LP We need primary
current to minimize input current.
to minimize input driving voltage. secondary
compensations
34
Primary and Secondary Compensations
35
Primary and Secondary Compensations
36
Resonant at 40 kHz
S/S voltage gain
P/P current gain
Primary and Secondary Compensations
S/P voltage gain
P/S current gain
37
S/S Compensation
Resonant
H
 Input inductive，current circulating loss
 Load independent output voltage
 Even worse at light load
Resonant
S
2M 2
RE
jv AB RE
M
 Low input resistance，small reactance
 Load independent current output
 Need open circuit protection
38
S/S compensation
Output voltage 408V，output current 66.2A
Huh, J.; Lee, S.W.; Lee, W.Y.; Cho, G.H.; Rim, C.T., "Narrow-Width Inductive Power Transfer System for Online Electrical Vehicles," in Power Electronics, IEEE39
Transactions on , vol.26, no.12, pp.3666-3679, Dec. 2011
S/S Compensation Example
Output voltage 408V，output current 66.2A
S/S uses less copper
Sallan, J.; Villa, J.L.; Llombart, A.; Sanz, J.F., "Optimal Design of ICPT Systems Applied to Electric Vehicle Battery Charge," in Industrial Electronics, IEEE Transactions
40
on , vol.56, no.6, pp.2140-2149, June 2009
S/P Compensation
C1
LL’
1:n
+
vAB
+
C3
LM’
RE vOS
−
+
S
vAB
−
n' 
1:n
+
RE
−
vOS
−
LS
M
L model
C design forvoltage
gain，
output needs
short circuit protection
 Input zero phase angle 1
PLL control
C3design forphase
anglemay fail due to high Q at light load
 Output load independent
4
2.8
2.4
2
RE=400
1.6
1.2
RE=200
0.8
0.4
0
20kHz
RE=50
30kHz
40kHz
50kHz
Input phase angle
Voltage gain
3.6
3.2
60kHz
41
S/P Compensation Example
Frequency 22 kHz
Kobayashi, K.; Yoshida, N.; Kamiya, Y.; Daisho, Y.; Takahashi, S., "Development of a non-contact rapid charging inductive power supply system for electric-driven
42
vehicles," in Vehicle Power and Propulsion Conference (VPPC), 2010 IEEE , vol., no., pp.1-6, 1-3 Sept. 2010
P/P Compensation
Input must be a current
  M 2 LS
I1
jC1
I1
jC1
M 2 RE
L2S
2
M RE
L2S
MI P
LS
LS I1
j MC1 RE
LS
C2
S
RE
 Load independent output voltage
RE
Input capacitive
43
P/P Compensation Example
Power：300W，primary current 15A，20kHz，load 6Ω，k=0.45，QS=1.77
Chwei-Sen Wang; Stielau, O.H.; Covic, G.A., "Design considerations for a contactless electric vehicle battery charger," in Industrial Electronics, IEEE Transactions
on,
44
vol.52, no.5, pp.1308-1314, Oct. 2005
P/S Compensation
+
vAB
–
i1
LP
C1
+
–jωMIS
−
Input must be a current source
LS C2
M
+
jωMIP
−
I1
jC1
RE
S
I1
jC1
2M 2
RE
RE I1
 2 MC1
 Load independent current output
 Input capacitive
45
P/S Compensation
S
C1 design for transfer function，
C2 design for input phase angle 
P
2M 2
RE I1
 2 MC1
RE
Input capacitive
*
*
M
LP
*
 Current input
n' 
I1
jC1
*
I1
jC1
 P 2  1 LP C1  1  LS  M  C2 
 Load independent current output
 Input zero phase angle
46
S/S Compensation optimization
Load independent output and high efficiency
Primary
Secondary
Efficiency
set
Optimum frequency
for maximal efficiency
Wei Zhang; Siu-Chung Wong; Tse, C.K.; Qianhong Chen, "Design for Efficiency Optimization and Voltage Controllability of Series–Series Compensated Inductive47
Power
Transfer Systems," Power Electronics, IEEE Transactions on , vol.29, no.1, pp.191,200, Jan. 2014
S/S Compensation optimization
Load independent output and high efficiency
Efficiency at ωM:
Efficiency maximized at QO1
Efficiency increase with
decreasing QO
Wei Zhang; Siu-Chung Wong; Tse, C.K.; Qianhong Chen, "Design for Efficiency Optimization and Voltage Controllability of Series–Series Compensated Inductive48
Power
Transfer Systems," Power Electronics, IEEE Transactions on , vol.29, no.1, pp.191,200, Jan. 2014
S/S Compensation optimization
Load independent output and high efficiency
When QP=QS
When λ<1/3 (k<0.577), near load QO1，ωM andωS
are nearly identical
replaceωM withωS
ωS is load independent
Efficiency at ωS and ωM
With a known load，design a
transformer such that ωM ≈ ωS to
have maximum efficiency
Wei Zhang; Siu-Chung Wong; Tse, C.K.; Qianhong Chen, "Design for Efficiency Optimization and Voltage Controllability of Series–Series Compensated Inductive49
Power
Transfer Systems," Power Electronics, IEEE Transactions on , vol.29, no.1, pp.191,200, Jan. 2014
S/S Compensation optimization
Load independent output and high efficiency
S/S compensation voltage gain：
Frequencies：
Wei Zhang; Siu-Chung Wong; Tse, C.K.; Qianhong Chen, "Design for Efficiency Optimization and Voltage Controllability of Series–Series Compensated Inductive50
Power
Transfer Systems," Power Electronics, IEEE Transactions on , vol.29, no.1, pp.191,200, Jan. 2014
S/S Compensation optimization
Load independent output and high efficiency
Operating freq.
Load independent
|Gv|
Maximum Eff.
ωH
ωM ≈ ωS (λ<1/3)
ωH cannot be ωS
CS design for efficiency
CP design for efficiency，such that ωH close toωS
Wei Zhang; Siu-Chung Wong; Tse, C.K.; Qianhong Chen, "Design for Efficiency Optimization and Voltage Controllability of Series–Series Compensated Inductive51
Power
Transfer Systems," Power Electronics, IEEE Transactions on , vol.29, no.1, pp.191,200, Jan. 2014
S/S Compensation optimization
Load independent output and high efficiency
Define ：
CP=1.1CPn
ηT
CP=1.3CPn
2
1
ηT
2
1
0.8
1.6
0.8
1.6
0.6
1.2
|Gv 0.6
|
1.2
0.4
0.8
0.4
0.8
0.2
0.4
0.2
0.4
0
100k
125k
150k
175k
Frequency
0
200k
0
100k
125k
150k
175k
|Gv
|
0
200k
Frequency
 Design Cp makingωH closer toωS to have a higher efficiency
 maximize efficiency of S/S compensated converter to have load
independent output
Wei Zhang; Siu-Chung Wong; Tse, C.K.; Qianhong Chen, "Design for Efficiency Optimization and Voltage Controllability of Series–Series Compensated Inductive52
Power
Transfer Systems," Power Electronics, IEEE Transactions on , vol.29, no.1, pp.191,200, Jan. 2014
S/S Compensation optimization
Load independent output and high efficiency
2M 2
RE
jv AB RE
M
If a constant output current is needed，S/S compensation should operate at
ωS. Proper output open circuit protection should be given.
53
Realization of Load Independent Output
iS LS
jωMIP
C i2
+
−
vOS
RE
Voltage source output
Current source output
54
Realization of Input Current
Primary side LCL compensation
LP
Lr
+
vAB
C1
ip
-jωMIS
Norton Eq.
Lr
C1
+
jωMIP
−
−
LP
LS
+
+
−
v AB
j Lr
is
M
ip
+
LS
+
+
-jωMIS
jωMIP
−
−
vOS
-
is
M
Secondar
y
Compens
ation
vOS
-
55
Primary and Secondary LCL Compensation
 IT is load independent and so is IO
 Suitable for multiple secondary windings application
 LCL need external indicator as large as LM，lower system power density.
56
LCC COMPENSATION
LP’ ip
ieq
 Minimize
Lf
CP
-jωMIS
LP'  LP 1 2CS1
 Compared with LCL compensation，LCC compensation can have
VAB
higher injected current.
Ieqv 
j  LP 1  2CS1 
 Current gain (normally less than 3 due to magnetics):
Qi  1
C1
CS1  C1
Esteban, B.; Sid-Ahmed, M.; Kar, N.C., "A Comparative Study of Power Supply Architectures in Wireless EV Charging Systems," Power Electronics, IEEE Transactions
57 on ,
vol.30, no.11, pp.6408,6422, Nov. 2015
LCC COMPENSATION
 Parallel capacitor Cf reduce inductance Lf；
 Load independent current output；
Siqi Li; Weihan Li; Junjun Deng; Nguyen, T.D.; Mi, C.C., "A Double-Sided LCC Compensation Network and Its Tuning Method for Wireless Power Transfer," Vehicular
58
Technology, IEEE Transactions on , vol.64, no.6, pp.2261,2273, June 2015
LCC COMPENSATION-INTEGRATED
 Magnetic coupling can improve power density。
Coupling Circuits
Weihan Li; Han Zhao; Siqi Li; Junjun Deng; Tianze Kan; Mi, C.C., "Integrated LCC Compensation Topology for Wireless Charger in Electric and Plug-in Electric 59
Vehicles,"
Industrial Electronics, IEEE Transactions on , vol.62, no.7, pp.4215,4225, July 2015
LCC COMPENSATION-INTEGRATED
Coupling
Equivalent
Matching：
Weihan Li; Han Zhao; Siqi Li; Junjun Deng; Tianze Kan; Mi, C.C., "Integrated LCC Compensation Topology for Wireless Charger in Electric and Plug-in Electric 60
Vehicles,"
Industrial Electronics, IEEE Transactions on , vol.62, no.7, pp.4215,4225, July 2015
SP/S Compensation
Primary parallel compensation
Primary series compensation
LP
ip
+
vAB
1
 2M 2
Z in 
 j LP  RP 
jCP
ZS
Z in 
LS
+
+
CP -jωMIS
jωMIP
−
−
-
is
M
1
jCP 
1
j LP  RP 
 2M 2
ZS
Misalignment, coupling reduced
Primary series compensation
Primary parallel compensation
combine
IP increases，can be over current. Is
may also increases.
IP decreases，so as Is.
Villa, J.L.; Sallan, J.; Sanz Osorio, J.F.; Llombart, A., "High-Misalignment Tolerant Compensation Topology For ICPT Systems," Industrial Electronics, IEEE Transactions
61
on , vol.59, no.2, pp.945,951, Feb. 2012
SP/S Compensation
原边串联电容将虚部补偿掉。
Input power
Load power
Villa, J.L.; Sallan, J.; Sanz Osorio, J.F.; Llombart, A., "High-Misalignment Tolerant Compensation Topology For ICPT Systems," Industrial Electronics, IEEE Transactions
62
on , vol.59, no.2, pp.945,951, Feb. 2012
SP/S Compensation
 Input zero phase angle；
 Insensitive to misalignment。
 Input resistance change with output load。
Villa, J.L.; Sallan, J.; Sanz Osorio, J.F.; Llombart, A., "High-Misalignment Tolerant Compensation Topology For ICPT Systems," Industrial Electronics, IEEE Transactions
63
on , vol.59, no.2, pp.945,951, Feb. 2012
S/S AND S/P COMPENSATION
 Ll 2 
 Voltage gain a function of n only
1
C2
+
vAB LM
-
vOS
RE
-
1
C1
 n 2 L'M 
n' 
1:n
 Input inductive
 L'l 
S/P
compensation
+
i2
*
S/S
compensation
i1
*
1
 Ll1 
 C1
1
 C2
LS n
L
1
 （假设 P  2 ）
M k
LS n
 Input resistive
 Voltage gain a function of n and k
Hou Jia，Chen Qianhong，Wong Siu-Chung，Tse Chi. K.，Ruan Xinbo．Analysis and control of series/series-parallel compensated resonant converter for contactless
64
power transfer[J]．IEEE Journal of Emerging and Selected Topics in Power Electronics，2015，3(1)：124－136．
S/SP COMPENSATION
Z1
C1 LL1 v
LM
LL2 C2
1:n
+
vAB
Z2
LM
−
Compensation： 2 
+
C3
RE
vOS
−
1
1
1

 2
Ll1C1 Ll 2 C2 n LM C3
Voltage gain a function of n only
 Input resistive
Hou Jia，Chen Qianhong，Wong Siu-Chung，Tse Chi. K.，Ruan Xinbo．Analysis and control of series/series-parallel compensated resonant converter for contactless
65
power transfer[J]．IEEE Journal of Emerging and Selected Topics in Power Electronics，2015，3(1)：124－136．
S/SP COMPENSATION
Voltage gain
8
n
Gv    2 
j C3  Z1 Z 3   Z1  j LM  Z 2   j LM

j LM

 = 4C p Cs (n 2 L2M  Lp Ls )+ 2 (Lp C p  Ls Cs )  1
Voltage gain at
Gv i  
8
2

j 3C1C2 LM RE
△=0，gain
becomes load
independent
n

1
i 
LM
1
LL1C1

1
LL2 C2

1
：
Z in i  
  n L
2
2
M
Gv i  
Finally：
n 2 LM C3
1
Z in  j LP 

jC1 j L 
S
Input impedance
Input impedance at
If 0，gain becomes LM
independent
C3  Z1 Z 3   Z1  ji LM  Z 2 
8
2
n
2M 2
1
1
|| RE

jC2 jC3
j LM RE
C3  1 RE  j n LM
2

RE
n2
If 0, then a pure
resistor
66
S/SP COMPENSATION
Resonant
frequency
Compensation
capacitor
Transformer
parameter
RL
fr = 40 kHz
C1 = 48.89nF, C2 = 44.2nF, C3 = 51.4nF
10 cm: kmax = 0.475, Ll1 = 324.967 , Ll2 = 362.56 , LM = 310.948 
20 cm: kmin = 0.231, Ll1 = 435.275 , Ll2 = 462.95 , LM = 134.85 
RLmin = 100 Ω, RLmid = 400 Ω, RLmax = 800 Ω
10
8
Constant freq.
6
control
Gv
4 fL_kmax
23.7k
2
0
20
fH_kmax
40k
30
40
fs(kHz)
50
60
67
S/SP COMPENSATION
Fundamental approximation is not able to
keep up with the accuracy. 。
Lot of higher
harmonics
68
Higher Harmonic Equivalent Circuit
Input voltage:
VAB _ m
Output current: I 2 _ m
4Vin

m
4I
 o
m
69
Higher Harmonic Equivalent Circuit
Input voltage:
VAB _ m
Output current: I 2 _ m
Voltage across LM
m=1:
m=3,5,7,9,…:
VLM _1  VAB _1
VLM _ m
VAB _ m
4Vin

m
4I
 o
m
k
vLM  t   1  k  VAB _1 sin s t   kv AB  t 
sine
square
Secondary current
m=1:

1 
I S _1  nVAB _1  jr C3 


Z
E
_1


iS  t   I S _1 sin s t  1 
m=3,5,7,9,…:
IS _ m  0
sine
70
Waveforms of Resonant Circuit
sine
square
vLM  t   1  k  VAB _1 sin s t   kv AB  t 
iS  t   I S _1 sin s t  1 
sine
iLM
71
Output Waveforms
Output current harmonics
Harmonic current and voltage
72
Experimental Comparisons
Po =1.5 kW
39.2kHz
Po =0.8 kW
Input current
Voltage across
parallel capacitor
73
S/SP COMPENSATION
0.82
Gv
0.8
0.78
Result from calculation with Fundamental
approximation
Result from calculation with higher harmonics
0.76
Experimental
result
0.74
200 300
500
700
900
Po(W)
1100
1300
1500
74
Switching of Series or Parallel Compensation on the Secondary Side
Battery charging needs two stages：
Constant Current，until battery reach a voltage level，
Constant voltage，until current diminishing to nearly none.
 Constant voltage ， S1 and S2 open， S3 connects RL to L2，forming a S/S
compensation，Ls = L1 + L2（dotted blue）
 Constant current ， S1 and S2 close， S3 connects RL in parallel with Cssp ，forming a
S/P compensation， Ls = L1。（solid red）
Auvigne, C.; Germano, P.; Ladas, D.; Perriard, Y., "A dual-topology ICPT applied to an electric vehicle battery charger," Electrical Machines (ICEM), 2012 XXth
International Conference on , vol., no., pp.2287,2292, 2-5 Sept. 2012
75
DYNAMIC TUNING
When there are variation of parameters, such as load, coupling and driving frequency，system
compensation may deviate from optimal point.
a Soft-Switched Variable Inductor
inside the resonant circuit
Hu, A.P.; Hussmann, S., "Improved power flow control for contactless moving sensor applications," Power Electronics Letters, IEEE , vol.2, no.4, pp.135,138, Dec.76
2004. doi:
10.1109/LPEL.2004.841311
DYNAMIC TUNING
 Use extra inductor or capacitor；
 Need bidirectional current switch；
 Discrete alteration of Capacitance or
inductance.
Three mode boost inductor secondary compensation
freewheeling period
Z. Pantic and S. M. Lukic, “A new tri-state-boost-based pickup topology for inductive power transfer applications,” in Proc. IEEE Energy Convers. Congr. Expo., Phoenix, AZ,
Sep. 2011, pp. 3495–3502.
Pantic, Z.; Lukic, S.M., "Framework and Topology for Active Tuning of Parallel Compensated Receivers in Power Transfer Systems," Power Electronics, IEEE Transactions
77
on, vol.27, no.11, pp.4503,4513, Nov. 2012
Part 4：Transformer Optimization
2. Basic Analysis
1. Introduction
3. Compensation
Network
4. Transformer
6. Design Example
5. Control
78
79