Optimal design of LLC resonant converter with improved controllability

The aim of this paper is to introduce generalized design and optimization methodology for LLC resonant converters. To investigate operation principles, deriving linear circuit and mathematical models, first harmonic approximation is used which to great extent can simplifies quantitative analysis. For optimal, high efficiency design of LLC converter with controllability feature over wide variation of input voltage, mathematical model of gain function and input impedance are reordered to be used as fitness function and constrain functions and ´Genetic Algorithm´ is used to achieve best possible combination of resonant tank elements. Optimized values of Q_e, L_n and n is selected and simulation is carried out using PSIM software to verify the accuracy of the proposed method.