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 undersea 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 nonmagnetic media of low conductivity. The 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. Recently, contactless (or contact-free) energy transfer (CET) systems have become more widely developed and investigated. This innovative technology brings about new possibilities of supplying mobile devices with electrical energy by allowing elimination of cables, connectors, and/or slip rings. This increases reliability and maintenance-free operation of such systems in critical applications such as aerospace, biomedicine, multisensors, and robotics. A large number of technologies for CET have been established, but these can be summed up in three commonly accepted terminologies: * CET
* Contactless (or contact-free) power transfer (CPT)
* Wireless power transfer (WPT).
In the most popular applications, the core of CET systems is the inductive or capacitive coupling between power source and load, and high-switching frequency power electronic converter for energy flow control. The...