Contactless Energy Transfer for Office and Domestic Applications

This paper presents a new method for shaping the magnetic field produced by multiple contactless energy transfer coils. It is shown in this work that by changing individual current phases of excited primary coils the shape of the magnetic field around the coils is changed. Furthermore, by carefully choosing specific coil current phases, the individual magnetic fields will cancel each other out far away from the coils but still retain most of their energy close to the coils. This is very beneficial when working with contactless energy transfersystems and electromagnetic interference (EMI) issues. A methodology for synthesis of a general multiple-input-multipleoutput (MIMO) contactless energy transfer system is also presented. Using the methods described, the energy transfer capability as well as the efficiency of a theoretical test setup excited with in-phase current sources as well as out-of-phase current sources are then tested and compared. The magnetic field intensity around the two setups is also calculated and compared.