Isolation type soft switching LCTCL multi-resonant direct-current converter with self-boosting function

Abstract

The invention discloses an isolation type soft switching LCTCL multi-resonant direct-current converter with a self-boosting function. The converter is composed of a self-boosting circuit, two half-bridge circuits, two LCTCL multi-resonant circuits and two full-bridge diode rectifying circuits on the secondary side, and is suitable for various occasions such as a photovoltaic power generation system, a battery charger and a switching power supply. The converter is characterized in that fundamental wave and third harmonic active power can be transmitted simultaneously, the utilization rate of resonance current is improved, reactive circulation is reduced, and the conversion efficiency of the converter is improved. The converter also has a self-boosting function, does not need an additional power device and a control circuit, is high in integration degree, and saves the cost. Besides, the converter also has an ideal soft switching characteristic, and all switching tubes can realize zero-voltage switching-on. Meanwhile, the rectifier diode on the secondary side can realize zero-current switching-on and zero-current switching-off, the switching loss of a power device is very low, and the efficiency of the converter is correspondingly improved. Therefore, the converter has the advantages of high power density, high efficiency, high frequency, low electromagnetic interference and thelike.

Description

technical field [0001] The invention relates to the fields of photovoltaic power generation systems and switching power supplies, in particular to an isolated soft-switching LCTCL multi-resonant DC converter with a self-boosting function. Background technique [0002] In recent years, the development and utilization of renewable energy sources such as photovoltaics, wind energy, and fuel cells have provided some new solutions to the problems of energy depletion and environmental pollution worldwide. In order to make full use of these distributed renewable energy sources, the DC microgrid has become a research hotspot of many scholars. However, due to the large impact of the environment, the output of these renewable energy sources is intermittent and changes with time, and the load demand is also uncertain. Therefore, a DC converter is required to maintain the stable and continuous operation of the DC microgrid. The DC converter converts the electric energy output by the r...

AI Technical Summary

Problems solved by technology

However, this converter also has some disadvantages

When the input voltage varies in a large range, in order to maintain a constant output voltage, the converter must adjust the switching frequency of the converter in a wide range, which leads to an increase in the loss of the converter

At the same time, due to the introduction of too high switching frequency, the influence of the parasitic parameters of the converter on the performance of the converter will not be ignored

Therefore, under a wide range of input voltage variation, the converter no longer has the characteristics of high efficiency and high power density. In the working state, a higher on-state loss will be introduced

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