Fixed-frequency resonant DC conversion device and control method thereof

Abstract

The invention discloses a fixed-frequency resonant DC conversion device and a control method thereof, which belongs to power electronic and power automation equipment and solves the problems of low light load efficiency and complex control of the existing resonant DC conversion system. The fixed-frequency resonant DC conversion device comprises a power conversion circuit, a resonant circuit, a high-frequency transformer, a rectifying circuit, a filtering circuit, a sampling and conditioning circuit, a controller and a driving circuit. The control method realizes the adjustment for the output energy of the resonant DC converter under the fixed frequency through controlling the combination mode of working modes of the resonant DC converter and the working time. Compared with the traditionalresonant DC conversion system, the device disclosed by the invention has the characteristics of high efficiency, simple control design, fixed frequency and the like, and achieves the efficient operation of the resonant DC converter in the full load range.

Description

technical field [0001] The invention belongs to power electronics and power automation equipment, and relates to a fixed-frequency resonant DC conversion device and a control method thereof. Background technique [0002] The resonant converter is a popular topology among various DC converters, which has the advantages of soft switching characteristics and magnetic integration characteristics. At present, there are mainly two control methods for resonant converters: variable frequency control and fixed frequency control. [0003] In the traditional fixed frequency control method, the input voltage is adjusted to obtain the required voltage by controlling the phase shift between the leading bridge arm and the lagging bridge; this method has three main disadvantages: (1) There is a large loop current; (2) High reverse recovery voltage; (3) Loss of soft switching characteristics under light load working conditions. In order to solve the above problems, some researchers use the...

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Problems solved by technology

[0006] In order to overcome the deficiencies of the prior art above, the present invention provides a fixed-frequency resonant converter device and control method to solve the problems of low efficiency, complicated control and narrow adjustment range of the existing resonant converter. Compared with the prior art , the present invention combines the advantages of traditional fixed-frequency control and variable-frequency control, which not only improves the efficiency of the resonant converter, but also makes the resonant converter have linear characteristics, and realizes simple and effective control

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