Variable capacitance type CLLC resonant converter

Abstract

The invention discloses a variable capacitance type CLLC resonant converter, which comprises a direct- current input power supply, first to fourth inverter bridge switching tubes, a resonant inductor, a resonant capacitor, a transformer, a variable capacitance element, first to fourth rectifier bridge diodes and an output capacitor; the direct-current input power supply is respectively connected with drain electrodes of first and third switch tubes and source electrodes of the second and fourth switch tubes; the resonant inductor is respectively connected with the source electrode of the first switch tube, the drain electrode of the second switch tube and a primary side dotted terminal of the transformer; the resonant capacitor is respectively connected with the source electrode of the third switch tube, the drain electrode of the fourth switch tube and a primary side synonym terminal of the transformer; a secondary-side dotted terminal of the transformer is connected with an anode of the first diode and a cathode of the second diode; the variable capacitance element is respectively connected with a secondary side synonym terminal of the transformer, an anode of the third diode and a cathode of the fourth diode; the output capacitor is respectively connected with the cathodes of the first and third diodes and the anodes of the second and fourth diodes. The variable capacitance type CLLC resonant converter is reasonable and reliable in structure, excellent in performance and higher in overall working efficiency.

Description

technical field [0001] The invention relates to the technical field of resonant converters, in particular to a variable capacitance CLLC resonant converter. Background technique [0002] It is known in the industry that in medium power applications, resonant converters have easy-to-implement soft-switching characteristics and high operating efficiency in the full load range, especially when operating in the optimal resonant mode. However, the resonant mode of traditional LC, LLC and other resonant converters has unit normalized voltage gain, so the voltage adjustment is generally realized by frequency modulation control, so that the working mode deviates from the resonant mode and enters the over-resonant or under-resonant mode, so It not only reduces the working efficiency, but also is more sensitive to load changes, and has higher requirements on the dynamic response of frequency modulation control. At the same time, the application of variable resonant elements provides ...

AI Technical Summary

Problems solved by technology

However, the resonant mode of traditional LC, LLC and other resonant converters has unit normalized voltage gain, so the voltage adjustment is generally realized by frequency modulation control, so that the working mode deviates from the resonant mode and enters the over-resonant or under-resonant mode, so It not only reduces the working efficiency, but also is more sensitive to load changes, and has higher requirements for the dynamic response of frequency modulation control

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