Rapid power commutation control method for dual-active full-bridge DC/DC converter

Abstract

The invention provides a rapid power commutation control method for a dual-active full-bridge DC / DC converter, and the method comprises the steps: S1, defining that power is transmitted from a primary side to a secondary side of the dual-active full-bridge DC / DC converter as positive transmission, and otherwise, the power is transmitted as negative transmission; s2, according to an initial power value and a target power value set by a user, judging how to change the direction of the transmission power, and according to known parameters, respectively calculating the required phase shift difference duty ratio sum between the primary side square wave voltage and the secondary side square wave voltage of the high-frequency transformer; and S3, calculating the negative pulse width duty ratio of the adjusted primary side square wave voltage of the high-frequency transformer and the positive pulse width duty ratio of the adjusted secondary side square wave voltage of the high-frequency transformer in the transient process so as to finish conversion from an initial power value to a target power value, eliminate direct current bias and realize soft switching. The equivalent resistance is considered during modeling and analysis, so that the risk that components are damaged can be further reduced, and the stability of the converter is improved.

Description

technical field [0001] The invention belongs to the field of power conversion technology improvement, and in particular relates to a transient control method for power commutation of a dual active full-bridge DC converter. Background technique [0002] In recent years, with the vigorous development of new energy technology, its drawbacks have gradually emerged, such as intermittent and unstable. For example, solar energy has the law of day and night interruptions, and wind energy is also closely related to seasons. As a bidirectional DC / DC energy transmission device, the dual active full-bridge DC / DC converter can store the electric energy generated by the new energy power generation equipment into the energy storage equipment such as super capacitors and batteries. When the load demand is large, the power generation equipment generates When the power is insufficient, the stored power can be released to the load through the dual active full-bridge DC / DC converter. [0003] ...

AI Technical Summary

Problems solved by technology

[0004] The existing technology ignores the equivalent resistance R in the power loop eq Influence on the transient characteristics of dual active full-bridge DC / DC converter, where R eq Including the resistance generated by PCB layout, switching devices, high-frequency transformers and power inductors, however, in practical applications, due to the equivalent resistance R eq Influenced by the influence, DC bias will still be generated during the transient process of power commutation, and the generated DC bias may cause damage to components and make the soft switching of switching devices invalid

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