Adaptive three-phase balanced control cascaded three-phase bridge converter

Abstract

The invention discloses a novel cascaded three-phase bridge converter and belongs to alternating current (AC) / direct current (DC) converters. The converter comprises three-phase AC power supplies, three input inductors and three cascaded three-phase voltage type bridge converters, wherein the three-phase AC power supplies are in star connection and do not have a neutral line. A voltage stress of a switching tube is reduced by using a connection mode of cascaded superposition of three-phase input line voltages, so the converter is applicable to high-voltage and high-power level occasions; and when three-phase input power supplies are unbalanced, inter-phase energy can be compensated for each other, so DC output voltages of each three-phase bridge are automatically equalized. By using cascade connection between bridge arms of the three-phase bridges, compared with a three-phase cascaded converter which is cascaded in same level (m level) and consists of single-phase H-bridge cascaded converters, the novel cascaded three-phase bridge converter has the advantage that: six active switching tubes and m+1 output capacitors are eliminated, so the cost and volume of the converter are reduced.

Description

technical field [0001] The present invention relates to a circuit topology of an AC / DC converter and its application, in particular to a cascaded three-phase bridge converter that can be applied to high-voltage and high-power occasions and can automatically solve three-phase balance control . Background technique [0002] With the continuous development of power electronic semiconductor devices and circuit integration technology and the continuous improvement of users' requirements for power quality, power electronic converters are increasingly used in high-power applications, such as the high-voltage side of power electronic transformers and large-capacity motors. drive etc. The commonly used power distribution voltage level is 10kV / 380V, and 20kV / 380V in some areas, but the voltage level of the general full-control device is about 1kV. Therefore, with the increase of the power of the rectifier device, the voltage or current withstand capacity of a single device is often ...

AI Technical Summary

Problems solved by technology

However, compared with the current type, the voltage type is currently the most widely used topology because of its advantages of low harmonics, high efficiency, and low electromagnetic interference, while the latter has relatively few applications.

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