Applying Mutual Inductance Identification to Achieve Cross-Coupling Compensation for Two-Receiver Wireless Power Transfer Systems

In this article, a cross-coupling compensation method is presented for two-receiver wireless power transfer (WPT) systems, based on the mutual inductance identification. Through the method, system output power can be improved, when the two receivers move within a considerable spatial range. Meanwhile, extra sensors are avoided to reduce system volume, weight, and complexity. First, a two-step identification process is presented on the basis of the system equivalent circuits. In the process, three mutual inductances of the two-receiver WPT system are obtained from one measured primary-side voltage and system load parameters. Then, no-cross-coupling and cross-coupling systems are compared to calculate the compensation capacitance values. Moreover, switch controlled capacitor (SCC) is adopted to compensate the cross-coupling, according to the identified mutual inductances and the calculated compensation capacitance values. Finally, a two-receiver WPT experimental prototype is developed, and the experimental results indicate that the maximum mutual inductance identification error is with 4%. Furthermore, the average system output power is improved from 10.490 to 28.600 W, within the reference spatial range while considering the load variation. The maximum output power increase is from 0.729 to 33.282 W.