Abstract— Paralleling of two LLC resonant converters leads
to a significant reduction of current stress in the output
filter capacitor, provided that the driving signals of both
converters are of equal frequency and with constant phase
shift of 90°. However, non influenceable tolerances of the
circuit elements, especially those of the resonant tank
circuit, cause unbalanced power distribution between the
paralleled converters, resulting in suboptimal circuit design.
Frequency controlled current balancing is proposed as
remedy in this paper, and prototype measurements are
presented to demonstrate the functional capability.