Reduction of Conducted Emissions Generated by WPT Systems with Multilevel Inverters using Spread Spectrum Approach

In this paper spread spectrum technique based on switching frequency modulation for the first time is applied to closed-loop wireless power transfer (WPT) systems with multi level inverters at the primary side. The effect of switching frequency modulation on the main performance characteristics of WPT system with multi level inverter operating in constant current mode is studied thoroughly. The results show that the spread spectrum technique is useful approach for reduction of conducted electromagnetic emission generated by multilevel-inverter-based WPT system with moderate impact on other important performance characteristics provided that recommendations given are considered.