High-gain isolated type direct current-direct current (DC-DC) convertor

Abstract

The invention discloses a high-gain isolated type direct current-direct current (DC-DC) convertor for fuel-cell power generation and belongs to the technical field of convertors. The convertor comprises an input current multiplier, a switch capacity multiplier, a clamping circuit and a transformer. The input current multiplier comprises a first input inductor, a second input inductor, a first switch tube and a second switch tube. The clamping circuit comprises a clamping capacitor Cc, a first clamping switch tube and a second clamping switch tube. The switch capacity multiplier comprises a first resonant capacitor, a second resonant capacitor, a first output capacitor C2a, a second output capacitor C2b and four rectifier tubes. The primary side of the transformer is connected with the input current multiplier and the clamping circuit respectively, and the secondary side of the transformer is connected with the switch capacity multiplier. When high-gain isolated type DC-DC convertor is applicable to the fuel-cell power generation and grid connection, the convertor needs an occasion with high gain, small input current ripple and high efficiency, and the convertor is also applicable to other types of new energy power generation including low-output-voltage power generation and the like.

Description

technical field [0001] The invention relates to the technical field of DC-DC conversion, in particular to a high-gain current feeding isolated converter. Background technique [0002] With the increasing shortage of energy sources, the development of new energy technologies has gradually become a focus of attention. Among them, the fuel cell power supply system has the characteristics of high energy density, no noise, no environmental pollution, and is not restricted by natural conditions such as sunlight and wind, and is favored. However, for fuel cell modules, the output voltage is generally 40V-50V, and the common DC bus voltage is often set at 200V or 400V, so a high-gain DC-DC converter needs to be inserted between the fuel cell output and the common DC bus. converter. In addition, the output voltage range of the fuel cell is wide, and large output current fluctuations are not allowed, which puts forward special requirements for the converter. [0003] Voltage-fed co...

AI Technical Summary

Problems solved by technology

[0004] Although the current-fed converter can reduce the output current fluctuation of the fuel cell and obtain high gain without a large turn ratio transformer, the output rectifier diode still works under hard switching conditions, and the reverse recovery problem is not has been solved

In addition, the buffer or clamping circuit should be designed with sufficient capacity to absorb the current in the boost inductor until the transformer leakage inductance current builds up to the boost inductor current value, which increases the complexity and cost of the circuit design

Images