In the framework of the EVIAC research project, sponsored by the European Union, different topologies of inductive charging systems with automatic connection (i.e. without driver intervention apart from parking the vehicle) have been developed.
The four systems considered encompass different technologies:
-High frequency coupler using a passive mechanical alignment system.
-High frequency asymmetrical coupler with active docking system.
-High frequency asymmetrical couplers with high positioning tolerance.
-Intermediate-frequency (400Hz) system.
The systems have been implemented and tested in both laboratory conditions and real usage.
Users needs in multi-user fleet public transport service have been analysed with respect to:
-The best choice of design for the cities taking into account safety, security and reliability aspects.
-The development of three different inductive charging systems that can respond to these user needs, particularly with an industrial and technological approach.
-The framework of a full scale public approach of self service cars at St-Quentin-en-Yvelines based on the charger with passive mechanical alignment.
-The constraints imposed by possible electromagnetic interferences.
Special interest has been given to the evaluation of EMC aspects, both on the conducted and radiated level, as it has been considered that the loosely coupled inductors typical for these systems are liable to be more sensitive on the field of EMC issues.
The energy consumption and the safety aspects of the systems have been evaluated and compared to conductive systems, as to assess the operational characteristics of the inductive charging technology and their potential to be developed into a product which is both safe, technically reliable and economically feasible.
Conclusions:
Introducing a user-friendly charging system for EV/HEV reduces the resistance of the citizen to accept it and helps to introduce into the city, the ZEV systems that are able to reduce the number of vehicles in the city and to improve traffic mobility.
Inductive charging system can become a key element of charging infrastructure in the cities. Automatic Rent-a-Car systems are an intermediate step between classic public transportation system and private cars. It is an extension of public transport that splits the latter into possibilities for local trips not coverable by public means.
It should be financed in the same way public transportation systems are financed.
With respect to costs: the maintenance costs are very similar to the costs of classic electric material; the energy costs are related to the benefit (more or less 50%) connected with the introduction of EV's.
For all other applications - buses, taxis, and fleets - the infrastructure is very similar to parking meters infrastructure i.e. with similar investments and maintenance costs.
The environmental advantages of inductive charging systems are strongly related with the advantages of introducing electric and hybrid transport systems in cities. They do not introduce particular urban problems considering the easy integration they allow. The choice of the exact inductive technology to be selected will be mostly dependent on the particular requirements of each system application.
