Wireless power transfer (WPT) has intrigued man for centuries. Indeed, powering a device or process from a distance without contact is thought provoking and challenging in many ways. These days, inductive approaches have become very popular and nearly commonplace, especially in consumer and mobile electronics, e.g. phone charger pads. Our group is focusing on an alternative approach, capacitive coupling, rather than inductive, for WPT in industrial automation and electric machines. A capacitive approach does not use coils or permeable cores, instead it uses thin conducting surfaces. Capacitively coupled transmitter and receiver structures are naturally suited for small gap (short distance) applications, which fall within the realm of automation. Specifically, we have demonstrated electric machine slip ring replacement, electric vehicle charging, and automation cable elimination at the ~kW power level.
