Comparative study of phase-shift, frequency, and hybrid control of the series resonant converter supplying the electric vehicle inductive charging interface

The electric vehicle inductive coupling battery charging interface can be driven from a variety of converters of which the frequency-controlled series-resonant converter has been demonstrated to have many desirable features. In this paper, the series-load and the Class D, or parallel-load, phase-controlled resonant converters are also investigated and are shown to be viable options for electric vehicle battery charging. A novel simple, yet accurate, analytical approach yields a single generic solution for the entire family of converters. This analysis is used to highlight important characteristics of resonant converters in the inductive charging application and to compare the topologies on a unified basis. The analytical results are verified experimentally.