Etude et mise en oeuvre du transfert de l'énergie électrique par induction : application à la route électrique pour véhicules en mouvement

摘要

Inductive power transfer has become a flourishing subject, considering the current geopolitical and environmental situation and the new technological possibilities. The electric road may lead to important and valuable consequences: extended range for electric vehicles and even hybrids, from a simple bonus to an infinite range, depending on the infrastructure set up, down-sized on-board batteries, reduction of the weight and cost of the vehicle and lowered importations of both battery cells and oil for the benefit of local investments .The solution developed uses a magnetic medium for the transfer. Therefore, it involves loosely coupled coils, implying inevitably strong leakage inductances and outstanding associated voltage drops. A new type of DC-DC converter was imagined to answer those issues. It is based on the concept of symmetry; a detailed analysis conducted with phasor diagrams leads to a specific working principle, which has been named the “voltage copying”. Thus, the DC/DC converter designed works with a realistic air-gap of 15 centimeters, a longitudinal tolerance to displacement up to +/-50% and a stable output voltage with low losses despite large coupling variations. And it all works without any communication between the ground part and the mobile part. These results make a dynamic charging seriously worth investigating.It requires to sequence the power supply of a multitude of small coils buried beneath the road surface, at the right time and for the right position. Putting inactive coils in a resonant short-circuit mode enables to use current measures to precisely detect the switching time from one coil to the next. This original solution, free of any position sensor, does not prevent the specific “voltage copying” property and the design principles developed in the first part.