Inductive Power Transfer Using Diverted Magnetic Field

A wireless power transfer (WPT) system comprising at least one power-transmitting unit and at least one power-receiving unit, an individual power-transmitting unit comprising:

• a loop-shaped magnetic core comprising one or more high-permeability (HP) core sections and one or more low-permeability (LP) core sections, the one or more HP core sections having a relative permeability higher than a relative permeability of the one or more LP core sections, all the HP and LP core sections being alternately arranged to form an interleaving pattern in forming the magnetic core;
• and
• a primary coil wound on the magnetic core for generating a magnetic flux in the magnetic core upon the primary coil being excited by an alternating current (AC) power source;
• an individual power-receiving unit comprising:
• a pickup core configured to overlie a first LP core section selected from the one or more LP core sections, the first LP core section connecting to two connecting surfaces of respective one or two HP core sections immediately adjacent to the first LP core section, the pickup core being further configured to partially overlap said respective one or two HP core sections around the two connecting surfaces, the pickup core having a relative permeability higher than the relative permeability of the first LP core section so as to cause at least a part of the magnetic flux to divert from the first LP core section to the pickup core when the individual power-receiving unit is parked adjacent to the individual power-transmitting unit such that the pickup core overlies the first LP core section and partially overlaps said respective one or two HP core sections;
• and
• a secondary pickup coil wound on the pickup core for inductively generating electrical power from the diverted part of magnetic flux, enabling electrical power supplied by the AC power source to be wirelessly delivered to the individual power-receiving unit.