Topological structure of seven-level ANPC converter

Abstract

The invention discloses a topological structure of a seven-level ANPC converter. The topological structure comprises a DC side, a first branch, a second branch, a third branch, a fourth branch and an auxiliary reversing branch, wherein the DC side comprises a DC support capacitor C1 and a DC support capacitor C2; the auxiliary reversing branch comprises a first branch, a second branch, a third branch and a fourth branch; the first branch comprises switch tubes S1a-S1c; the second branch comprises switch tubes S2a-S2c and switch tubes S5-S7; the third branch comprises switch tubes S3a-S3C and switch tubes S8-S10; the fourth branch comprises switch tubes S4a-S4c; the switch tubes S1a-S1c, the switch tubes S2a-S2c and the switch tubes S3a-S3c are connected with a static voltage-sharing resistor Rs in parallel separately; and the auxiliary reversing branch comprises a first auxiliary reversing branch, a second auxiliary reversing branch and a third auxiliary reversing branch. According to the topological structure, the voltage-sharing problem of series switch tubes of the converter in a zero-level state switching process is solved; and after the topological structure is adopted, the problem of unbalanced voltage division, caused by zero-level state switching, of the series switch tubes of the seven-level ANPC converter can be effectively solved.

Description

technical field [0001] The invention relates to the technical field of electric energy conversion, in particular to a seven-level ANPC converter topology. Background technique [0002] In recent years, with the continuous improvement of industrial production technology and people's living standards, people's demand for high-voltage large-capacity converters has also continued to increase, making multi-level converters a research hotspot for scholars from all over the world. Compared with traditional two-level converters, multi-level converters have flexible control, more output levels, and output waveforms closer to sine waves. Under the same withstand voltage value of power switching devices, higher output can be obtained. Voltage. At present, the topologies of multilevel converters used in the industrial field mainly include diode clamped, capacitor clamped, hybrid clamped, stacked multi-unit and active neutral point clamped (ANPC). Among them, there are only two support...

AI Technical Summary

Problems solved by technology

[0003] In view of this, the purpose of the present invention is to provide a seven-level ANPC converter topology to solve the voltage equalization problem of the series switch tubes in the zero-level state switching process of the seven-level ANPC converter

Images