Magnetic Power Distribution Using Controlled Permeability Bypass and Its Multiple Output Investigation

An alternative wireless power transfer (WPT) using near-field magnetic power distribution is proposed. The new method is characterized by using a low permeability path in serial with a high permeability path as the main unit or the basic cell. The output can be tapped into the main unit by paralleling the low permeability path. The magnetic cores are integrated with different permeability to form a multiple-transmitter geometry. Every transmitter corresponds to more than one receiver that is integrated with back-end circuits such as rectifiers to convert ac voltage into dc voltage. The receiver can be easily installed in the electrical devices, and hence power is transferred wirelessly to drive the devices. Analysis of the working mechanisms of the proposed WPT system is given in detail and design considerations are also investigated. Power loss distributions for the converter and coupler are also analyzed fully. Experimental results show that a basic cell driven by an 80 kHz pulse wave, supplying three resistive loads at 321 W achieves 86.6% efficiency. The system efficiency can be maintained at a high level over a wide output power range. Finally, a magnetic panel comprising seven basic cells supplying multiple loads is demonstrated. Results show the feasibility of the proposed system by lighting up multiple LED loads.