A kind of multi-port isolated bidirectional dc-dc converter

Abstract

The invention discloses a multi-port isolating bidirectional DC-DC (direct current to direct current) converter which is used for a mixed energy storing system. The converter comprises a phase-shifting transformer and a primary side circuit and a secondary side circuit which are respectively connected with a primary side and a secondary side of the phase-shifting transformer; the secondary side circuit comprises a two-path Buck / Boost converting circuit, wherein the two-path Buck / Boost converting circuit comprises two input / output ends and two bridge arm midpoints and the two bridge arm midpoints are respectively connected with two ends of the secondary side of the phase-shifting transformer; and the primary side circuit comprises at least one two-path Buck / Boost converting circuit, wherein the two-path Buck / Boost converting circuit comprises two input / output ends and two bridge arm midpoints and the two bridge arm midpoints are respectively connected with two ends of the primary side of the phase-shifting transformer. The invention further discloses a voltage matching and controlling method of the multi-port isolating bidirectional DC-DC converter and the mixed energy storing system comprising the converter. Compared with the prior art, the multi-port isolating both-way DC-DC converter can realize complete matching of voltage at two ends of a transformer and can prolong the service lives of a storage battery and a super capacitor.

Description

technical field [0001] The invention relates to a DC-DC converter, in particular to a multi-port isolated bidirectional DC-DC converter for a hybrid energy storage system. Background technique [0002] Energy storage systems applied to electric vehicles and distributed renewable energy power generation often use a hybrid energy storage method of batteries and supercapacitors to improve the performance of the energy storage system. The batteries provide energy storage, and the supercapacitors provide peak power. A three-port bidirectional DC-DC converter is used to combine the battery, supercapacitor and DC bus, making it easier to achieve high power density, centralized control and effective energy management. [0003] The three multi-port isolated bidirectional DC-DC converter is mainly based on the expansion of the bridge bidirectional DC-DC converter. A typical two-terminal voltage type full-bridge bidirectional DC-DC converter such as figure 1 shown. Transformer leaka...

AI Technical Summary

Problems solved by technology

[0010] The technical problem to be solved by the present invention is to overcome the technical problem in the prior art that the voltages at both ends of the transformer cannot be fully matched under a wide voltage input range, and to provide a multi-port isolated bidirectional DC-DC converter, which can be used in relatively In a wide voltage input range, the voltage matching at both ends of the transformer can be realized, and the output current ripple can be reduced, which is beneficial to prolong the service life of the battery and super capacitor

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