National Technical University of Athens School of Electrical &Computer Engineering SmartRue Research Group FastInCharge Project: The Concept and Challenges of the Inductive Charging for Plug-in Electric Vehicles Ioannis D. Karakitsios (email:jkarak@power.ntua.gr) Phd student in the School of Electrical &Computer Engineering at the National Technical University of Athens Research member of SmartRue Research Group (Prof. Nikos Hatziargyriou) (www.smartrue.gr)
Inductive Charging Inductive Charging: Contactless power transmission from the station to the vehicle Two kind of inductive chargers: 1. Stationary: The electric vehicle starts charging as soon as it enters the station: EV charging no longer requires cables Increased safety Ease of use The charger is embedded underground Resistance in harsh environments Less maintenance required 2. On-Route: The vehicle receives power while in motion: Autonomy issues are no longer a concern
The Concept of Inductive Charging AC/DC Rectifier DC/AC High Frequency Inverter AC/DC Rectifier Connection to the grid Charging Coil Pick-up In order to provide sufficiently high power to the vehicle, a high frequency current is required (10-50kHz) The high frequency current of the charging coil causes a magnetic flux to pass through the surface of the vehicle s pick-up. This magnetic flux induces an AC voltage in the pick-up coil.
Example of Inductively Coupled Ferrite Cores The power supply rail comprises a number of different poles consisting of ferrite cores. In this particular structure, the current runs through the poles in such a way that the magnetic flux passes differently through each side of the pick-up: Upward in Side 1 (Red Colour) and Downward in Side 2 (Blue Colour) Two different coils (one for each side) are used in the pick-up to aggregate the induced voltage. The alternating polarities of the poles considerably reduce the electromagnetic field generated from the power supply rail. Side 1 Side 2 Side 1 Side 2
Example of Inductively Coupled Ferrite Cores Displacement: Moving Direction Power delivered to the vehicle x
Example of Inductively Coupled Ferrite Cores Lateral Displacement y y y Power delivered to the vehicle y
FastInCharge Project: http://www.fastincharge.eu/ FastInCharge is a project supported by European Union s Seventh Framework Programme, with a budget of 2,397,042.60. The full name of the project is Innovative Fast Inductive Charging Solutions for Electric Vehicles The project has already started since October 2012 and will last 36 months. It is based on a consortium which gathers 9 organizations from 6 European Member States: 2 SME, one specialised in charging infrastructure for electric vehicles (DBT) and another in innovation management (EQY), 1 industrial group of automotive engineering (BATZ), 3 research organisations, specialists of automotive engineering, contactless power and energy management systems (Tecnalia, TU Gabrovo, NTU Athens), 1 end-user (Douai), 1 cluster (ACWS), 1 OEM (CRF). FastInCharge Partners: DBT, France EQY, France BATZ, Spain TECNALIA, Spain TUG, Bulgaria NTUA, Greece DOUAI, France ACWS, Slovakia CRF, Italy
FastInCharge Project: http://www.fastincharge.eu/ Aim of the project: The FastInCharge project aims at fostering the democratisation of electric vehicles in the urban environment by developing an easier and more comfortable charging solution This solution will enable to ease the Electric Vehicles (EV) use by the large public and facilitate their implementation in the urban grid. FastInCharge s intention is to develop a cost-effective modular infrastructure offering a global solution for EV charging. Its success will boost research in the direction of dynamic charging solutions FastInCharge Objectives In the scope of FastInCharge, a complete charging infrastructure will be developed and demonstrated in order to: Address consumers acceptance of electric vehicles by getting rid of the autonomy issue, Test its implementation and assess its easy feasibility, Optimize the energy delivery to the stations and its interaction with the grid and vehicles, Study the impact of its integration in the urban environment to foresee eventual problems that would occur in the frame of a real integration
FastInCharge Project: http://www.fastincharge.eu/
FastInCharge Concept Regarding the displacement, the pick-up coil receives the maximum magnetic flux, while it lies exactly above the charging coil. The magnetic flux lines of the pick-up coil are reduced while the vehicle moves away from the charging coil. As far as the coils (charging coil & pick-up coil) are concerned, two coils of the exact same size will be used. In order to reduce the exposure to the magnetic field induced, the coils will be covered by an aluminum plate. One module will be used for the stationary station, while four modules of the exact same characteristics will be used for the on-route station This modular approach allows implementing easier stationary and on-route charging solutions and also decreases the overall cost of the infrastructure, because it relies on mass-production of a single element. Such an approach for the on-route charging infrastructure can greatly help cities and local authorities to deal with the investment problem linked with the integration of heavy cost infrastructures. The investment and the construction work can be distributed along the years and avoid huge one-shot investments.
FastInCharge Concept The FastInCharge topology is similar to the general concept of inductive charging. Regarding the converter control, feedback signals from the pickup coil will be used. Those signals will be transmitted wirelessly from the pick-up to the converter of the station. Inductive Charger topology
FastInCharge: Inductive Charger Prototype The Technical University of Gabrovo (TUG, Bulgaria) has already developed a prototype regarding on-route charging. This prototype allows a power delivery of 30kW through an air gap of 9cm, achieving an efficiency of around 90%. Instead of constantly delivering power to all of the charging coils, the structure enables a smart concept so that power is delivered to one charging coil at a time: When a vehicle approaches the station, power is provided to the first charging coil. As soon as the input current reaches a certain low limit (which means that the vehicle has almost passed the first charging coil) power is not provided to the first coil anymore, while power is now provided to the second one. Regarding the converter of the station, such a concept can be achieved with 1 common IGBT module in continuous operation mode and 4 IGBT modules for the four Charging Coils. Coil 4 Coil 3 Coil 2 Coil 1
FastinCharge: The Vehicle CRF (Italy) will integrate the pickup coil in the hybrid vehicle Daily Electric Van 35S. The pickup coil will be placed on the back of the vehicle The power delivered to the vehicle depends on the displacement between the charger and the pick-up. A mechanical moving system will be developed by BATZ (Spain) assuring the correct position of the coils. This mechanism will guarantee a high charging efficiency, while enabling a fast energy transfer.
Not Charging Full Power FastinCharge: Energy Management Power Management Opportunity! Considering the stationary charging stations, a great opportunity for power management arises, if the driver just intends to leave their vehicle on the station for an amount of time greater than the time needed for charging. 100% Available Power According to the available power offered from the grid, keeping in mind the SoC of each vehicle, the intended departure time of the driver as well as the elasticity offered, decisions will be made regarding 5 or 10-minute time intervals: At each time interval directions will be given to each station either to charge the electric vehicle at a given amount of power, or not to charge at all. Power Plan 0% 100% 50% 0% 100% 0% 50% Power
Thank you very much for your attention! Prof. Nikos Hatziargyriou email:nh@power.ece.ntua.gr Ioannis Karakitsios email:jkarak@power.ece.ntua.gr SmartRue Research Group www.smartrue.gr