Multi-Parallel Sending Coils for Movable Receivers in Inductive Charging Systems

The design of the sending side is critical in inductive power transmission systems. Multi-coil systems can be an interesting solution to reach larger and more flexible charging area. The challenge thereby is that during movements the voltage at the receiving side gets amplitude ripple. In this paper, a comparison between different coil systems such as Single Input Single Output (SISO), Parallel Multi Input Single Output (P-MISO) and a Controlled Parallel Multi Input Single Output (CP-MISO) coils systems is carried out. The aim of the investigation is to select a suitable architecture, where the resulting magnitude ripple of the receiver voltage due to coil movement are minimized. Results shows that a big receiving coil radius and a small sending coil radius in a CP-MISO coil system delivers the lowest ripples having a magnitude of around 40 mV
_p-p
and a suitable maximal load voltage of 250 mV
_p-p
.