Design of an Inductive Contactless Power System for Multiple Users

The technique of inductive contactless energy transfer (CET) has found its application in specific industrial applications where an (air) gap between energy source and load is preferable or even required. A relative new application area of CET is where CET is part of a general energy distribution network. As an example, electrical sockets might give problems in bathrooms for safety reasons: CET provides a solution because of inherent electrical isolation between source (grid) and loads (e.g. hair dryer or electrical shaver). For such application this paper reports on the design of a contactless power system that is able to supply to multiple users simultaneously, analogously to the regular plug-and-socket network. The proposed contactless system consists of a special energy supply cable where clamps (each maximum 240 W) can be mounted on at arbitrary locations along the cable while electrical isolation is maintained between cable and clamps. Result is a supply cable design and a prototype with 2 clamps, which are compared by means of analytical calculations, simulations and experimental results.