Highly Resonant Wireless Power Transfer(HR-WPT) is a method for contactless and wireless power transfer, wireless power, and can be used for charging electric vehicle batteries. The HR-WPT method is used in WiTricity.
The principle of the HR-WPT method is based on resonance between a transmitting resonator and a receiving resonator. With this wireless power method, energy can be transmitted over longer distances. The quality of the resonators, which still transmit energy even with weak coupling, and the quality of the impedance matching networks( IMN) are decisive for the efficiency. For charging electric vehicles, this means that the electric vehicle does not have to be positioned precisely above the transmitter resonator.
Charging systems based on the HR-WPT method have to realize charging powers of a few watts up to several kilowatts. Their efficiency reaches values of 94 % at outputs of several kilowatts.