Four-quadrant three-level power unit and high-voltage inverter

Abstract

The invention relates to a four-quadrant three-level power unit. The four-quadrant three-level power unit is characterized in that the four-quadrant three-level power unit comprises three-phase three-level rectifier bridges which are respectively connected to a DC (direct current) bus, equalizing resistances, DC-link capacitor modules and single-phase three-level inverter bridges, wherein the three-phase three-level rectifier bridges and the single-phase three-level inverter bridges are connected back to back, each of the three-phase three-level rectifier bridges includes three phases first bridge arms and each of the three phases first bridge arms includes four power switch tubes, antiparallel follow current power tubes and two clamping modules, and each of the center taps of the clamping modules is connected to each of the center taps of the DC-link capacitor modules. The invention also provides a high-voltage inverter including the four-quadrant three-level power unit. The four-quadrant three-level power unit utilizes the three-level topological structure to enable the output voltage of the power unit to be increased substantially, so that the amount of the power units which are in overall unit series with the high-voltage inverter can be decreased substantially and the overall unit is high in reliability and long in service life.

Description

technical field [0001] The invention relates to the field of high-voltage frequency converters, and more specifically relates to a four-quadrant three-level power unit and a high-voltage frequency converter. Background technique [0002] With the development of electric transmission technology, especially frequency conversion speed regulation technology, high-voltage frequency converter technology as a large-capacity transmission has also been widely used. The high-voltage motor can realize stepless speed regulation by using a high-voltage frequency converter, which meets the requirements of the production process for motor speed regulation and control, so as to improve the output and quality of products. In addition, the use of electric motors can greatly save energy and reduce production costs. [0003] The power unit series multi-level high-voltage inverter is currently the most popular technical solution for domestic manufacturers. It sets an input isolation transformer...

AI Technical Summary

Problems solved by technology

[0010] The technical problem to be solved by the present invention is to provide a four-quadrant three-level power unit and a high-voltage frequency converter for the defect of insufficient output voltage of the existing power unit unit

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