Generalized State-Plane Analysis of Bidirectional <i>CLLC</i> Resonant Converter

The CLLC resonant converter is a promising candidate for high efficient, bidirectional power transfer applications, such as vehicle-to-grid on-board charger and hybrid vehicle dc&#x2013;dc converter. Nevertheless, the analysis of still remains challenging because its complex multiresonant nature several storage elements. In this article, circuit method based on change variables presented that maps state-space equations into two decoupled sets equations. analyses are carried out in state-plane coordinate systems, then results mapped onto original region. proposed used to thoroughly analyze operating continuous conduction mode (CCM). voltage current stresses components, zero switching condition, output gain, characteristic diagram, boundary CCM&#x002F; discontinuous obtained. accuracy approach verified by experiments 3 kW with GaN transistors primary secondary side switches. confirm either direction transferring.