Two-level cascaded multilevel inverter

Abstract

The invention discloses a two-level cascaded multilevel inverter which is formed by the series connection of a front level unit and a back level unit. The front level unit is formed by n switch-diode units and a peak elimination switch, wherein the DC power supply negative end of an ith switch-diode unit is connected to the connection point of the switch and diode in an (i+1)th switch-diode unit, the peak elimination switch is connected across the connection point of the switch and diode in a second switch-diode unit and the negative end of the DC power supply of an nth switch-diode unit, a back level unit input side end point A is introduced from the connection point of the switch and diode in a first switch-diode unit, an end point B of the back level unit is introduced from the DC power supply negative end of a last switch-diode unit, and the back level unit is an H bridge inverter circuit. According to the two-level cascaded multilevel inverter, the voltage peak problem of a traditional cascaded switch-diode inverter output voltage base is solved, and the two-level cascaded multilevel inverter has the advantages of low cost and high reliability.

Description

technical field [0001] The invention belongs to the field of inverters, in particular to a two-stage cascaded multilevel inverter. Background technique [0002] With the development of power electronics technology, inverters are used more and more widely. The multi-level inverter has been widely used in the fields of medium and high voltage speed regulation and new energy power generation due to its advantages of large output capacity, low harmonic content of output voltage and current, and low reverse voltage of the switching tube. [0003] Compared with traditional inverters, the outstanding disadvantage of multilevel inverters is that as the number of levels increases, the number of power electronic full-control devices required increases accordingly. Although the switching devices of the multi-level inverter do not need high withstand voltage because the voltage is evenly distributed among the switching devices or unit modules, each fully-controlled power electronic dev...

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to provide a two-stage cascaded multilevel inverter for the shortcomings of the existing cascaded multilevel topology, which solves the problems existing in the output voltage base of the traditional cascaded switch-diode inverter. The problem of voltage spikes has the advantages of low cost and high reliability

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