Five-level inverter topology circuit and five-level inverter

Abstract

The invention provides a five-level inverter topology circuit and a five-level inverter, the circuit comprising a first bridge arm, a second bridge arm, a third bridge arm, a fourth bridge arm, a fifth bridge arm, a sixth bridge arm, a high frequency transformer, an inductor, and a first filter capacitor. Each of the first bridge arm, the second bridge arm, the third bridge arm, the fourth bridgearm, the fifth bridge arm, and the sixth bridge arm is formed by a switching device and a freewheel diode, wherein the switching device is inversely parallel to the freewheel diode. The first bridge arm and the second bridge arm are connected in series to form a first series branch, the third bridge arm and the fourth bridge arm are connected in series to form a second series branch, the fifth bridge arm and the sixth bridge arm are connected in series to form a third series branch, and the first series branch, the second series branch and the third series branch are connected in parallel. According to the invention, natural current sharing is achieved; it is convenient to control current; the circuit stability is improved; at the same time, multi-level output is realized, which is beneficial to reduction of harmonic components; the operating frequency of a switching device is reduced; and the working efficiency of a micro-inverter is further improved.

Description

technical field [0001] The invention belongs to the technical field of power electronics, and more specifically relates to a five-level inverter topology circuit and a five-level inverter. Background technique [0002] With the development of distributed power generation technology, the micro-inverter system is more and more popular in the market due to its advantages in power generation efficiency, safety and reliability. However, the cost and work efficiency of the micro-inverter system are two factors. important factors restricting its development. The traditional inverter topology circuit uses a full-bridge interleaved parallel circuit, which has two control modes, bipolar and unipolar, and the size and loss of the filter inductor are large, which will also reduce the working efficiency of the micro-inverter; The impedance of the bridge circuit is not uniform, so there is a difference in the output current, which will also adversely affect the heat dissipation and life ...

AI Technical Summary

Problems solved by technology

The traditional inverter topology circuit uses a full-bridge interleaved parallel circuit, which has two control modes, bipolar and unipolar, and the size and loss of the filter inductor are large, which will also reduce the working efficiency of the micro-inverter; The impedance of the bridge circuit is not consistent, so there is a difference in the output current, which will also adversely affect the heat dissipation and life of the micro-inverter

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