A Modular and Distributed Grid Interface for Transformer-less Power Supply to Road-side Coil Sections of Dynamic Inductive Charging Systems

This paper presents a distributed converter
interface for the road-side infrastructure of dynamic inductive
power transfer (IPT) systems for roadway-powered electric
vehicles (RPEV). The proposed system configuration is based on
a modular multilevel topology, with each individual module
supplying power at a floating potential to a road-side coil section.
Transformer-less integration with the high voltage distribution
grid is enabled due to the series connection of modules as seen
from the ac-side. When supplying a high number of road-side
coil sections, the proposed system can significantly reduce the
cabling requirements compared to a conventional low voltage dc
distribution system. A control strategy for the presented system
configuration is introduced, and simulation results demonstrate
the operation under various loading conditions. It is shown how
balanced three-phase currents at the interface with the grid can
be ensured independently of the load distribution and the
movement of the vehicles along the road. The presented control
strategy also ensures that the individual capacitor voltages of
each module are balanced and bounded within the design range.