A DC to AC power conversion device

Abstract

The invention discloses a DC-AC power conversion device, which comprises a DC conversion unit, an AC conversion unit, and a filter unit connected in sequence; the DC conversion unit is used to output a corresponding DC bus voltage according to a DC power supply, and the DC bus voltage is higher than The voltage of the DC power supply; the AC conversion unit is used to convert the DC bus voltage into corresponding AC voltage and AC current, and the filter unit is used to filter the ripples of the AC current and AC voltage, and provide smooth AC voltage and AC current in load. The present invention obtains a higher DC bus voltage and reduces the requirement for decoupling capacitors on the DC bus side through the DC conversion unit. Compared with the two-stage structure, no transformer is needed, the DC and AC units are at the same level, and the number of switching tubes used is small, resulting in The DC bus voltage is higher, the switch tube conduction loss and turn-off loss are reduced, the control is simple, the reliability is high, and the overall efficiency is high.

Description

technical field [0001] The invention relates to the technical field of electric energy conversion, in particular to a DC AC power conversion device. 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 ab...

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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