A DC to AC power conversion device

Abstract

The invention discloses a direct-current / alternating-current power supply conversion device. The direct-current / alternating-current power supply conversion device comprises a direct-current conversionunit, an alternating-current conversion unit and a filtering unit which are sequentially connected. The direct-current conversion unit is used for outputting corresponding direct-current bus voltageaccording to a direct-current power supply, and the direct-current bus voltage is higher than the voltage of the direct-current power supply. The alternating-current conversion unit is used for converting the direct-current bus voltage into corresponding alternating voltage and alternating current, and the filtering unit is used for filtering ripple waves of the alternating current and the alternating voltage and providing smooth alternating voltage and alternating current to a load. The higher direct bus voltage is obtained and the requirement for a direct-current bus side decoupling capacitor is reduced through the direct-current conversion unit. Compared with a two-stage structure, a transformer is not needed, the direct-current and alternating-current units are in the same stage, the number of switch tubes is small, the obtained direct-current bus voltage is higher, the on loss and the off loss of the switch tubes are reduced, the control is simple, the reliability is high, and theoverall 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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