A high-gain high-frequency isolated bidirectional cascaded dc/dc converter and its control method

Abstract

The invention discloses a high-gain high-frequency isolation bidirectional cascaded DC / DC converter and a control method thereof, wherein the converter includes: a first cascade module and a second cascade module connected in cascade; the first cascade module Including: the first capacitor, the first switch network unit, the first resonant network unit or the first DC blocking network unit, the high frequency isolation transformer, the second resonant network unit or the second DC blocking network unit, the second The switch network unit, wherein, the first resonant network unit corresponds to the second resonant network unit, and the first DC blocking network unit corresponds to the first DC blocking network unit; the second cascade module includes: the second cascaded in series The capacitor, the third switch network unit, and the third capacitor, and a third inductor connected in series between the third switch network unit and the third capacitor. By adopting the cascaded structure, the voltage gain of the low-voltage side and the high-voltage side can be flexibly set, which solves the problems of small transmission ratio of the existing converter and single-stage BUCK / BOOST isolation and duty cycle close to 1.

Description

technical field [0001] The invention relates to the technical field of power equipment, in particular to a high-gain high-frequency isolation bidirectional cascaded DC / DC converter and a control method thereof. Background technique [0002] Bidirectional DC / DC converters are widely used in DC uninterruptible systems, aviation power supply systems, solar power supply systems, shipboard power supplies and other occasions because they can realize the bidirectional flow of energy. Cascaded bidirectional DC / DC converter is a kind of bidirectional DC / DC converter. It has the advantages of two parts that can be optimized separately, high power density, and can realize large transformation ratio conversion. Therefore, it is widely used in large voltage transmission. applications, such as aerospace power supply, aircraft high-voltage DC power distribution systems, etc., especially in distributed power supply systems, the application of cascaded bidirectional DC / DC converters is more ...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the embodiment of the present invention is to provide a high-gain high-frequency isolation bidirectional cascaded DC / DC converter, which solves the problem of existing single-stage bidirectional isolation by adopting a cascaded structure to make the voltage gain ratio of the low-voltage side and the high-voltage side flexible. DC / DC converter voltage transmission ratio is small, and the isolation and duty cycle of single-stage BUCK / BOOST are close to 1. Its gain can be flexibly changed and adjusted according to needs, realizing bidirectional energy flow, multi-mode control mode and high-gain power conversion. Electrically isolated from high frequency

Images