Magnetic Integrated Current Sharing Characteristics of Interleaved LLC Resonant Converter
Yang Yugang1, Wu Han1, Guan Tingting2
1. Institute of electrical automation Liaoning Technical University Huludao 125105 China; 2. State Grid Liaoning Panjin Power Supply Company Panjin 124000 China
Abstract：In order to expand the capacity, LLC resonant converters mostly use a two-phase or multi-phase parallel structure. However, due to the inevitable deviation of the resonant element parameters of each phase in the interleaved LLC resonant converter, mainly including resonant inductance and resonant capacitance, the voltage gains between the LLC resonant converters are not equal, resulting in the unbalanced current of each phase. In order to solve this problem, a magnetic integrated current sharing scheme for 180° interleaved parallel LLC resonant converter is proposed. By magnetically integrating each resonant inductor, the primary current and load current of each LLC circuit can be balanced automatically without adding additional circuit and changing control strategy. It not only maintains the inherent soft switching characteristic of LLC resonant converter, but also improves the efficiency and reduces the number of resonant inductors from two to one. An 1kW experimental prototype of two-phase interleaving parallel magnetic integrated LLC resonant converter was built to verify the effectiveness of the current sharing scheme.
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2019, Vol. 34 
