Traveling Magnetic Field for Homogeneous Wireless Power Transmission

A novel concept for wireless power transmission using inductive coupling is proposed to transmit power homogeneously over a large working area. This concept includes a specially designed winding group on the transmitting side to generate a traveling magnetic field, which causes an alternating magnetic flux through a receiving coil that is located in this field and, therefore, induces a voltage in the coil. The prototype system provides an effective working area of 180 times 220 mm for one or more power receivers that is 4.0 mm thick and 11.5 mm in diameter. Each receiver receives a constant power of about 330 mW at 3.1 plusmn 0.4 V dc operating voltage throughout the working area. A possible application of this concept is the powering of untethered microrobots