Modified Series-Series Compensation Topology for WPT Systems

Wireless Power Transfer Systems use a wide selection of different compensation topologies to enhance one or the other of their characteristics. Among the simplest topologies, the series-series compensation offers high efficiency in a wide range of transferred power but requires an effective control of the output voltage and of the supply current when used in applications where the load varies substantially in order to protect the system from overvoltage or overcurrent. This paper presents a modified series-series compensation topology that inherently implements this protection at the expenses of a small decrease of the transfer efficiency. At high loads, the modified series-series topology operates as the conventional one, but at low loads its behavior changes limiting the transmitting side current and the output voltage. A preliminary analysis of operations of the proposed topology is performed in the time domain, then it is completed in the phasor domain and, finally, the obtained results are checked against those obtained by simulation implemented in the PSIM environment.