Isolated bidirectional active full-bridge DC-DC converter

Abstract

The invention discloses an isolated bidirectional active full-bridge DC-DC converter, which is realized through series connection of two transformers and parallel connection of two full-bridge output ends at a low-voltage side based on an isolated bidirectional active full-bridge converter. Switching tubes in the corresponding positions in two full-bridge circuits at the low-voltage side of the converter are synchronously switched on and off. The on-off of the ninth switching tube K1 and the tenth switching tube K2 is determined by the proportion of the high-voltage side and the low-voltage side. Through a method of series connection and voltage division of the transformers at the primary sides of the transformers, the voltage input range of the primary sides of the transformers can be increased; and through a method of parallel shunting at the secondary sides of the transformers, the loss of the switching tubes is reduced, so that the loss of the whole circuit is reduced, and thus the circuit has relatively high energy conversion efficiency in an occasion of a relatively large voltage transformation ratio.

Description

technical field [0001] The invention relates to the technical field of power conversion, in particular to an isolated bidirectional active full-bridge DC-DC converter. Background technique [0002] In a regenerative DC power supply system, the equipment usually needs a battery as a backup power supply. The voltage level of the battery is often much lower than the voltage level of the DC bus. Therefore, a bidirectional DC converter is required to step down the voltage to charge the battery, or the battery is boosted. Feed energy to the DC bus. [0003] Such as figure 2 As shown, if the non-isolated converter is used in the occasion where the voltage difference between the two sides is very large, the voltage adjustment range and the conversion efficiency of the converter are not very ideal, and there are potential safety hazards because the electrical isolation is not used; the isolated two-way The converter solves the deficiencies in the voltage adjustment range and safety...

AI Technical Summary

Problems solved by technology

[0003] like figure 2 As shown, if the non-isolated converter is used in the occasion where the voltage difference between the two sides is very large, the voltage adjustment range and the conversion efficiency of the converter are not very ideal, and there are potential safety hazards because the electrical isolation is not used; the isolated two-way converter, which solves the shortcomings of non-isolated converters in terms of voltage adjustment range and safety

However, when the voltage transformation ratio is relatively large, the voltage input range of the high-voltage side is not large enough, and the voltage and current stress of the switch tube on the low-voltage side are relatively large, so there are corresponding deficiencies.

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