Research on Hybrid Double-Bridge Buck-Boost LLC Resonant Converter

With the continuous development of science and technology, the demand for wide-range DC/DC converters with electrical isolation capabilities is also expanding. In order to achieve a wide range of input, this paper proposes a hybrid dual-bridge buck-boost LLC resonant converter topology. This structure has the following characteristics: 1) It has an ultra-wide gain range of 8 times and has good boost and buck capabilities; 2) The converter operates at a fixed frequency at the resonant frequency, has good load adjustment characteristics; 3) The converter can achieve smooth switching between multiple operating modes, the gain is continuously adjustable, and has excellent transient performance. This paper introduces its working principle and design considerations, and builds a 50W prototype for experimental verification.