High-gain high-frequency isolation bidirectional cascade DC/DC converter and control method thereof

Abstract

The invention discloses a high-gain high-frequency isolation bidirectional cascade DC / DC converter and a control method thereof. The converter comprises a first cascade module and a second cascade module which are in cascade connection, wherein the first cascade module comprises a first capacitor, a first switch network unit, a first resonance network unit or a first blocking network unit, a high-frequency isolation transformer, a second resonance network unit or a second blocking network unit and a second network switch unit which are sequentially cascaded in series, and the first resonance network unit corresponds to the second resonance network unit, and the first blocking network unit corresponds to the second blocking network unit; the second cascade module comprises a second capacitor, a third switch network unit and a third capacitor which are sequentially cascaded in series, and a third inductor is connected between the third network switch unit and the third capacitor in series. By adopting a cascade structure, flexible setting of voltage gains of a low-voltage side and a high-voltage side is realized, and the problems that the transmission ratio of an existing converter is small and the single-stage BUCK / BOOST isolation and duty ratio is close to 1 are solved.

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 power supply systems, aviation power supply systems, solar power supply systems, shipboard power supplies and other occasions because they can realize bidirectional flow of energy. The 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 voltage transmission. In some occasions, such as aerospace power supply, aircraft high-voltage DC power distribution system, etc., especially in distributed power supply systems, the application of cascaded bidirectional DC / DC converte...

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

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