Reactive power compensation in three phase high output inductive power transfer

Abstract

Inductive power transfer becomes increasingly more popular as a method for contact less charging of high power loads. Enabled by the rapid progress in power electronics components and controls, the power transfer solutions cross the previously unattainable boundaries of power levels and cost limits. Because of the high frequencies necessary for voltage induction in the secondary parts of the transformers and because of a rather low magnetic coupling, the system would have to constantly supply high levels of the reactive power, generating very high losses and limiting the available output power. Various tuning techniques have developed to tune-out the reactive power. In this paper a systematic approach to tuning of a high power three phase coupled transformer is presented and arithmetical calculations backed by simulation utilizing its values from the electromagnetic FEA analysis. The approach is based on the fundamental frequency approximation neglecting the higher order harmonics which is valid for tuning the system at the fundamental harmonics of the switching frequency.