Power conversion circuit

Abstract

The invention discloses a power conversion circuit which comprises an input DC source, a DC conversion unit, an AC conversion unit and a filtering unit. The DC conversion unit is configured to outputa DC bus voltage according to a DC power supply, wherein the DC bus voltage is higher than a voltage of the DC power supply; the AC conversion unit receives the DC bus voltage and outputs an AC voltage and an AC; the filtering unit filters out ripples of the AC and the AC voltage to provide a smooth AC voltage and AC to a load. The power conversion circuit makes the voltage stress of a switching tube smaller, uses fewer switching tubes than a conventional two-stage scheme, reduces the conduction loss and turn-off loss of the switching tube, and improves the efficiency of a whole converter.

Description

technical field [0001] The invention relates to the technical field of electric energy conversion, in particular to a power conversion circuit. Background technique [0002] With the increasing emphasis on energy saving and environmental protection, new energy power generation is widely used. However, due to the influence of external environment and other factors, new energy power generation systems such as solar / wind energy have a wide output voltage range, and their electromagnetic working environment is harsh. Equipped with a high-efficiency and high-reliability DC-AC conversion device with high boosting capacity, the new energy output voltage is converted into an AC voltage with a voltage frequency that meets the requirements. The traditional DC-AC conversion circuit has low reliability in the electromagnetic interference environment due to the bridge arm through problem, and its AC output voltage needs to be lower than the DC input voltage, which cannot meet the above w...

AI Technical Summary

Problems solved by technology

[0002] With the increasing emphasis on energy saving and environmental protection, new energy power generation is widely used. However, due to the influence of external environment and other factors, new energy power generation systems such as solar / wind energy have a wide output voltage range, and their electromagnetic working environment is harsh. Equipped with a high-efficiency and high-reliability DC-AC conversion device with high boosting capacity, the new energy output voltage can be converted into an AC voltage whose voltage frequency meets the requirements

The traditional DC-AC conversion circuit has low reliability in the electromagnetic interference environment due to the problem of bridge arm straight-through, and its AC output voltage needs to be lower than the DC input voltage, which cannot meet the above working requirements

[0003] The existing solution is to add an AC transformer or a DC converter to the DC-AC circuit to achieve the step-up function, but the AC transformer is bulky and heavy, and the implementation cost is high, and the two-stage structure of the DC converter makes the system complex. And affect the efficiency, and their reliability has not been improved; the existing unipolar converters such as impedance source converters have boosting capability and high reliability, but the boosting work needs to use the bridge arm through state, the switch tube High current stress and conduction losses, low system efficiency, and only suitable for three-phase AC output applications

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