A composite network model for load-independent output and near unit power factor in WPT system

It is well known that when applying wireless power transfer technology to energy storage loads, higher-order compensation networks can implement the load-independent output characteristics and simplify the control system. Analysis methods based on the equivalent model can effectively reduce the design complexity of high-order compensation networks. However, additional analysis is required to maintain zero phase angle of input voltage and input current and implement soft switching during the entire charge process simultaneously, when these analysis methods are adopted. Therefore, a composite network model, which is able to systematically analyze the load-independent output characteristics, zero phase angle, and soft-switching conditions of the higher-order compensation network, is proposed in this paper. To verify the reliability and effectiveness of the proposed composite network model, a 100-W lab prototype charger with the double-sided LCC compensation circuit has been built. Moreover, the composite model can be applied to other higher-order networks.