Five-level topological unit

Abstract

The invention relates to a five-level topological unit, which is connected between a positive electrode and a negative electrode of a direct-current power source. The five-level topological unit comprises a first switch unit, a second switch unit, a third switch unit, a fourth switch unit, a fifth switch unit, a sixth switch unit, a seventh switch unit, an eighth switch unit, a ninth switch unit,a tenth switch unit, an eleventh switch unit, a twelfth switch unit, a thirteenth switch unit, a fourteenth switch unit, diodes in anti-parallel connection with two ends of each switch unit, a seventeenth diode, an eighteenth diode, a first capacitor, a second capacitor, a third capacitor, a fourth capacitor and a current limiting inductor. The five-level topological unit is capable of providing high alternating-current voltage under the condition that low loss is kept, overvoltage of two ends of a flying capacitor and part of switch tubes or diodes can be prevented, alternating current side cost and loss of an alternating-current / direct-current converter can be effectively reduced, and high reliability is realized.

Description

technical field [0001] The invention relates to the technical field of power electronics, in particular to a five-level topology unit. Background technique [0002] A bidirectional AC-DC converter is a converter that converts DC power into AC power or converts AC power into DC power. With the continuous development and progress of society, human beings' demand for energy is increasing day by day, and new energy sources such as photovoltaics and energy storage account for an increasing proportion of energy. As its core, photovoltaic inverters and energy storage converters have become more and more fierce in the market competition in recent years. In order to meet market demands, more and more multi-level AC-DC converters have been introduced into the market, such as five-level AC-DC converters. [0003] Traditional five-level AC-DC converters need to adopt voltage equalization measures and larger snubber circuits to prevent overvoltage across flying capacitors and some swit...

AI Technical Summary

Problems solved by technology

[0004] Based on this, it is necessary to use voltage equalization measures and larger absorbing circuits in traditional five-level AC-DC converters to prevent overvoltage across flying capacitors and some switch tubes and diodes, which will increase cost and reliability. To solve the problem of poor performance, a five-level topology unit is provided

Images