DC/DC converter structure for high-gain fuel cell vehicle and control method

Abstract

The invention provides a DC / DC converter structure for a high-gain fuel cell vehicle and a control method and belongs to the field of power system design and application for new energy vehicles. The DC / DC converter structure comprises an upper bridge circuit and a lower bridge circuit which are symmetrically arranged in structure and are connected in parallel, wherein the upper bridge circuit comprises a first inductor, a second switch tube, a second inductor, a second conducting diode and a first capacitor connected in series; a positive electrode terminal of a fuel cell is connected with a first switch tube through the first inductor and then connected to a negative electrode terminal of the fuel cell; the positive electrode terminal of the fuel cell is connected to a midpoint of the second switch tube and the second inductor through a first conducting diode; and the midpoint of the second inductor and the second conducting diode is connected with the negative electrode terminal of the fuel cell through a third switch tube. According to the DC / DC converter structure, the disadvantage of a low boost ratio of a traditional boost topology is avoided, the disturbance of input voltageto output voltage during wide range variation is offset and the overhigh cost is avoided.

Description

technical field [0001] The embodiments described in this application generally relate to DC converters and their control methods, which belong to the field of new energy vehicle power system design and application, and in particular, relate to a high-gain fuel cell vehicle DC / DC converter structure and its control method. Background technique [0002] With the promotion of new energy vehicles, fuel cell vehicles have the incomparable advantages of internal combustion engine vehicles such as high energy conversion efficiency and environmental friendliness without going through the heat engine process and being not limited by the Carnot cycle. At the same time, they can still maintain the high speed of traditional internal combustion engine vehicles. , long-distance driving, safety, comfort and other performances, it is considered to be the first choice for clean and efficient transportation in the 21st century. However, a DC / DC (direct current / direct current) converter must b...

AI Technical Summary

Problems solved by technology

Due to the existence of the coupling transformer, the isolated topology is large in size, high in cost and relatively low in efficiency; the traditional non-isolated boost topology (such as boost, buck-boost, etc.) has good dynamic response and high efficiency, but due to the The low voltage ratio cannot meet the needs of the DC bus high-voltage platform

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