Design of a Contactless Energy Transfer System for an Electric Vehicle

Inhalt:
This paper presents the design and dimensioning of a contactless energy transfer setup for an electric vehicle. The aim is to operate the setup in two different power levels with the same design for the secondary and primary side respectively. The resulting reactive power is compensated by capacitors in series on both sides. It is aimed to keep the battery voltage and the coupling factor variable in a defined range. The adjustment of both power levels to the characteristic battery curve is realized by switching the power electronics on the secondary side between a half bridge and a full bridge rectifier. The system is dimensioned such that the transfer function has the same slope like the battery’s characteristic curve. The greatest appearing coupling factor determines the inductivity on the secondary side, whereas the primary side’s inductivity is fixed by the maximum voltage at the input inverter. Depending on the coil’s current limitation and the capacitor’s voltage limitation there are two alternatives for the primary side’s coil size and the inverter topology.