Magnetic Field Emission Comparison for Series-Parallel and Series-Series Wireless Power Transfer to Vehicles – PART 1/2

Resonant circuits of wireless power transfer system can be designed in four possible ways by placing the primary and secondary capacitor in a series or parallel order with respect to the corresponding inductor. The two topologies series-parallel and series-series under investigation have been already compared in terms of their output behavior (current or voltage source) and reflection of the secondary impedance on the primary side. In this paper it is shown that for the same power rating series-parallel topology emits lesser magnetic fields to the surroundings than its series-series counterpart at steady state resonant operation. First of all analytical expressions for the above mentioned statement are presented and is later substantiated with simulations on a finite element solver (Comsol). Results for variation of the magnetic emissions ratio for the two topologies are presented in this paper for different gap distance between the two inductors, horizontal distance from the coils and turn ratio.