A contactless energy transmission system

Most mains-operated equipment in use today is connected to the supply via plugs and sockets. These are generally acceptable in benign environments but can be unsafe or have limited life in the presence of moisture. In explosive atmospheres and in under-sea applications special connectors must be used. This paper describes a technique, the Contactless Energy Transfer System (CETS), by which electrical energy may be transmitted, without electrical connection or physical contact, through non-magnetic media of low conductivity. CETS, which has been used to transfer up to 5 kW across a 10 mm gap, employs high-frequency magnetic coupling and enables plug-in power connections to be made in wet or hazardous environmental conditions without the risk of electric shock, short-circuiting or sparking. Energy may be transmitted without the necessity for accurately manufactured "plug and socket" mechanisms and may be transmitted from source to load even when there is relative motion. Load-source voltage matching may be made inherent to the system.