Electromagnetic Compatibility of Contactless Power Transfer Modeled in FEM Analysis Software

This paper deals with basic parameters of contactless power transfer (CPT) and modelling of CPT in FEM analysis software. There are described basic equations for comput- ing parameters of CPT components. The main part of this paper refers about creating CPT transformer model in multiphysics software Maxwell Ansys to determine basic CPT parameters such as induction and impedance of CPT transformer, its electromagnetic fleld and its efiect on surroundings. CPT operates at high frequencies so its electromagnetic compatibility with other electric devices is very important because it may cause serious risks of fail of devices such as pacemakers or communication devices. 1. INTRODUCTION OF CONTACLESS POWER TRANSFER (CPT) Contacless power transfer is action when electric energy is transferred between two physically unconnected electric devices. Electromagnetic induction is used to transfer energy between gal- vanically isolated electric devices. This solution of energy transfer is very useful in environment of applications where conventional electricity wire transfer would be impractical or even dangerous. CPT is used in many applications such as toothbrushes, mobile phones and public transportation for charging electric devices. Figure 1 shows basic CPT component blocks which are used for contactless power transfer. 2. CPT ANALYSIS As shown in Figure 1. CPT consists of many functional blocks. The main part is CPT transformer which is formed by two large gap air coils. To achieve high e-ciency of energy transfer CPT trans- former has to operate at high frequencies. But high operational frequencies cause high impedance of CPT transformer and increase reactive power transferred by CPT. There the primary and sec- ondary capacity compensations are used on both sides of CPT transformer to reduce reactive power values.