LLC Resonant Converter Topologies and Industrial Applications-A Review

Owing to the advantages of high efficiency,high energy density,electrical isolation,low electromagnetic interference(EMI)and harmonic pollution,magnetic integration,wide output ranges,low voltage stress,and high operation frequency,the LLC resonant converters are widely used in various sectors of the electronics-based industries.The history and development of the LLC resonant converters are presented,their advantages are analyzed,three of the most popular LLC resonant converter topologies with detailed assessments of their strengths and drawbacks are elaborated.Furthermore,an important piece of research on the industrial applications of the LLC resonant converters is conducted,mainly including electric vehicle(EV)charging,photovoltaic systems,and light emitting diode(LED)lighting drivers and liquid crystal display(LCD)TV power supplies.Finally,the future evolution of the LLC resonant converter technology is discussed.

Modeling and optimal design of LLC resonant converter using whale optimization algorithm

Resonant converter(RC)was brought under research in the 80’s widely,which can attain very small switching loss,therefore,facilitating resonant topologies to function at the high switching frequency.It is well addressed in the review that the optimal parameterization of the resonant converter is a crucial task.While the literature has come out with different methodologies,they are highly conceptual and so the uncertainty due to high theoretical impact persists.This paper intends to develop a Parameter Optimization(PO)algorithm for designing and developing of LLC-RC.The proposed algorithm overwhelms the limitation by introducing a nonconceptual model based on the simulated outcome.Specifically,the resonant current under start-up conditions is acquired from the literary outcome,and the intelligent model is constructed.Based on the proposed model,a renowned search algorithm called as Whale Optimization Algorithm(WOA)is exploited to optimize the time constant of the resonant converter,which is a critical design parameter.The objective model is derived as a function of start-up time and so the start-up time can be minimized.Moreover,the response speed of the output voltage is also increased.The proposed Whale Optimization Algorithm based Parameter Optimization(WOAPO)is compared with the conventional techniques such as IAPO,Ant Bee Colony-PO(ABC-PO),Particle Swarm Optimization-PO(PSOPO),FireFly PO(FFPO)and Grey Wolf Optimization(GWOPO).The obtained result verifies the performance of the proposed method in modeling LLC-RC system.