Inductive technology for battery
charging
Stefan Milchev
Nikolay Madzharov
Anton Tonchev
TUG
Webinar, Tecnalia, Spain
09 October, 2014
Inductive Power Transfer Technologie
By its physical nature inductive method of energy transfer can be defined as
"Open transformer with resonant magnetic coupling". This is a commonly
used definition of the process, despite its application. The primary side of this
transformer is defined as “Transmitter” and the secondary (one or more than
one) “Receiver” or “Pick up”
Typical IPT construction
Basic concepts of IPT
Small air gap:5-10mm (SG-IPT)
Large air gap:7-300mm(LG-IPT)
FastInCharge IPT concept for charging of EV
 Development of fast static charging station;
 Development of on-route charging infrastructure;
 Static and on-route solutions to be based on identical IPT modules.
Technical specification of FastInCharge IPT modules
Parameters of IPTM
Input HF voltage to the primary coil 600 V 2000 V
Input HF current to the primary coil
Input HF power to the primary coil
Output FF voltage of secondary coil
Output HF power of secondary coil
Output HF current of secondary coil
Air gap between primary and
secondary coils
Operating Frequency
Efficiency
Weight of the secondary coil
Dimensions of the secondary coil
80 A 300 A
32 kVA
260 – 380 V
30 kW (at 380V output voltage)
80 A
60 mm 10 mm
Dimensions of the primary coil
Charging time
Maximum misalignment between
coils
80x70x9 cm
20 – 30 min
In direction X(L): 15 cm ; In direction Y(W):
10 cm
10 – 50 kHz
80 – 92 %
18- 25 kg
80x70x6 cm
The first step, of the project development is choice of
the location of IPTM in a EV
The second step is to determine main electrical and
mechanical parameters of IPT module
- Numerical simulation of electro-magnetic fields, electrical calculation
and some preliminary electrical measurements;
- Specified electrical parameters of IPTM are base data for development
of all primary and secondary power electronic modules;
- All specified mechanical parameters and air gap dimensions for static
and on-route charging mode are basic data for development of
mechanical moving system for positioning of IPTM.
• IPT TRANSFORMER – PRIMARY COIL
Dimensions 800mm
700mm
Volume
56 dm^3
Weight
28kg (incl. AL shell)
Note
For the first Prototype
100mm
Simulation of magnetic field distribution
between primary and secondary coils
Magnetic field dissipation without Aluminum shield
Simulation of magnetic field distribution between
primary and secondary coils
Magnetic field concentration – effect of Aluminum shield implementation
Simulation of magnetic field distribution between
primary and secondary coils
Magnetic field dissipation – effect of misalignment between coils
“On route” – primary coil construction
Components:
1. Basalt fiber concrete cover
2. Epoxy protective layer
3. IPT Litz coil
4. Ferrite bars with Aluminum supporting frame
5. Bottom concrete base
Special basalt fibers will be used for enforcement of
the concrete structure and improving the strength
Picture of developed primary coil
Dimensions: 816/716/80
Weight: 33,5 kg
Magnetic shield
Ferrite core
Litz wire turns
Inside view
Matching primary electrical circuit to the coil
Matching transformers and Capacitors
Secondary EV’s electrical circuits
Secondary IPT coil + AC / DC Module
EV side – Design of AC / DC Module
FastInCharge concept of on-route infrastructure
In red are marked sensors for switching primary coils in a charging mode
“On route” – primary coil distances and power distribution
Terms:
EPT – Efficient Power Transfer area
CS – Coil switching section
Lcoil – Length of each coil
Dcoil – Distance between coils
Laboratory prototype for investigation and demonstration of
contactless charging of EV, developed by TUG
Charging coils for static
and on-route mode
Charging station- static and
on-route mode
INVESTIGATION OF DEVELOPED IPT MODULES
WITH REAL BATERY LOAD
OVERAL VIEW OF Testing Battery Bench DEVELOPED BY CRF
Overall view of testing equipment
Test bench
TTC 90
COHDA
START, STOP, Uset ,Iset
Umeasured, Imeasured
Measurement technique
TTC 90
Impedance Analyzer
IPT primary
Current probe
100A, 100kHz
IPT secondary
AC/DC module
Agilent 1 GHz
Thermo vision
camera
Charging station modules
Charging
station
Charging station
body
TTC 90
COHDA
IGBT inverter and Control system
Matching capacitors
Matching trafos
Conclusions
•
•
•
•
Redesigning and optimization of some elements value, for example IPT
secondary turns and capacitance of secondary matching capacitors are
implemented.
The new optimized elements not deviate the specified electrical
parameters in FIC Technical specification.
The revised operating modes of all elements ( currents and voltages) are in
accordance with their catalog electrical data.
All electrical and temperature tests guaranty reliable operating mode of all
charging modules.
Thank you for your attention