A comparative guide to the main steady-state characteristics of four-element current-source resonant converters

High-frequency resonant converters possess several advantageous properties that make them well suited for high power density applications, such as on aerospace vehicles. In this paper, a comparison of high frequency resonant converter topologies with four energy storage elements is presented. It first describes how all possible circuit topologies for such converters under current-source and voltage- or current-sink conditions were characterized. The analytical results and expressions obtained regarding the converter's main steady state characteristics (including input-output transfer function, DC gain, high-frequency-gain slope, input impedance, resonant frequencies, load invariant gains and load invariant frequencies) were then tabulated for easy reference. This table provides valuable insight about which of these converters offer possible advantages (in terms of steady-state characteristics) over lower-order (two-element and three-element) resonant converters; those converters are identified for future in-depth investigation. Furthermore, the table is also helpful for designers trying to identify suitable alternatives for satisfying the given converter requirements of particular applications.