Low-voltage stress ZVS high-gain Boost converter

Abstract

The invention belongs to the technical field of electricity, and discloses a low-voltage stress ZVS high-gain Boost converter. The converter is composed of two switch tubes, four capacitors and threeinductors, and a diode. An anti-reverse diode of a traditional secondary Boost converter is replaced by the capacitor, the switch tube is moved forwards to an input end, an input side diode is furtherreplaced by the switch tube, an original switch tube is a main tube, and the two are conducted in a complementary mode; meanwhile, an auxiliary inductor and an auxiliary capacitor are additionally arranged. The voltage gain of the low-voltage-stress ZVS high-gain Boost converter provided by the invention is G = (1 + D) / (1-D), and high gain can be realized at a relatively low duty ratio. Comparedwith a traditional secondary Boost converter, the voltage stress the switch tubes and part of diodes of the low-voltage-stress ZVS high-gain Boost converter is reduced to a certain extent under the same working condition, and meanwhile, zero-voltage switching-on of the two switch tubes in the converter and natural switching-off of the diodes are realized, so that the switching loss is reduced, and the efficiency is improved.

Description

technical field [0001] The invention relates to the field of electrical technology, in particular to a low-voltage-stress ZVS high-gain Boost converter. Background technique [0002] With the increasing problems of environmental pollution and energy crisis, distributed new energy grid-connected power generation technologies such as photovoltaic power generation and fuel cell power generation have received extensive attention and research. Since the output voltage of battery units such as photovoltaic cells and fuel cells is low and has a wide range of variation, in order to meet the input voltage requirements of grid-connected inverters, it is often necessary to use multiple battery units in series. The reliability of this solution is low, and the later maintenance cost is high. In order to solve the above problems, a DC / DC converter with high boost capability can be used to directly increase the output voltage of a single new energy battery to the input voltage level requi...

AI Technical Summary

Problems solved by technology

A higher voltage gain can be achieved by connecting multiple switched capacitors in parallel, but the complexity of the system and the difficulty of control increase, and the cost is relatively high

The cascaded Boost converter can also significantly improve the boosting capability of the converter and reduce the number of passive components, but the switching tubes and diodes of the subsequent stage are subjected to a large voltage stress (for the output voltage), which increases the difficulty of device selection and the switching loss, making it difficult to further improve the efficiency of the converter

The secondary boost converter reduces the number of switch tubes and their driving devices by multiplexing the switch tubes in the cascaded boost converter, but the problem of high voltage stress of the switch tubes and diodes is still not resolved

In addition, the switching tubes of the above-mentioned high-gain converters are all hard switches, the system efficiency is low, and the switching tube will be accompanied by a large voltage spike when it operates, which will increase the voltage stress of the switching device and aggravate the problem of electromagnetic interference (EMI)

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