Single-phase current type inverter with LC active boosting buffer network

Abstract

The invention relates to a single-phase current type inverter containing an LC active boosting buffer network. The single-phase current type inverter comprises the LC active boosting buffer network, asingle-phase inverter bridge and a single-phase filter which are cascaded in sequence, and the LC active boosting buffer network comprises a boost inductor, a buffer capacitor and a boost buffer network switch which is composed of two power switches and two diodes. The single-phase inverter bridge comprises four two-quadrant power switches capable of bearing bidirectional voltage stress and unidirectional current stress. The single-phase current type inverter has the advantages of single-stage boost power conversion, high power density, high conversion efficiency, low output waveform distortion degree, high reliability during overload and short circuit, low cost and the like, and can suppress secondary ripple current input into a direct-current voltage source; and the inverter is suitablefor boosting, medium-capacity and small-capacity single-phase passive and grid-connected inversion occasions, and more shows unique advantages along with the appearance of novel devices such as bidirectional interruptable IGBTs.

Description

technical field [0001] The invention relates to the technical field of power electronics, in particular to a single-phase current-type inverter with an LC active boosting buffer network. Background technique [0002] The inverter is a static conversion device that uses power semiconductor devices to convert direct current into alternating current, which is used for AC loads or connected to the public grid for power generation. [0003] Due to the increasing shortage of fossil energy (non-renewable energy) such as oil, coal and natural gas, serious environmental pollution, global warming, nuclear waste and environmental pollution caused by nuclear energy production, energy and the environment have become major issues facing mankind in the 21st century. . Renewable energy (green energy) such as solar energy, wind energy, tidal energy and geothermal energy has the advantages of being clean, pollution-free, cheap, reliable, and abundant. People are paying more and more attentio...

AI Technical Summary

Problems solved by technology

When this type of inverter works normally, the voltage on the DC side must be greater than the peak value of the phase voltage on the AC side, so there is an obvious defect: when the voltage on the DC side (such as the output capacity of photovoltaic cells) decreases, such as in rainy days or at night, the entire power generation The system will stop functioning and the utilization of the system will drop

In this regard, the following two methods are often used to solve this problem: (1) adding a Boost DC converter in the front stage to form a two-stage power conversion circuit structure, which increases the complexity, loss and cost of the circuit; (2) ) output plus a single-phase power frequency transformer, thus greatly increasing the volume, weight and cost of the system, especially difficult to adapt to today's sharp rise in the price of copper and iron raw materials

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