High frequency isolation type three-level inverter based on Boost converter

Abstract

The invention discloses a high frequency isolation type three-level inverter based on a Boost converter. The high frequency isolation type three-level inverter is composed of an input direct-current electrical source unit, an input filter, a high frequency isolation type three-level inversion unit with an energy storage inductor, a high frequency transformer, a cycle converter, an output filter and an output alternating load which are sequentially connected. Power switch tubes are staggered to be connected, three sorts of voltage levels can occur on the input energy storage inductor L, the size of the inductor is decreased, the voltage stress of the power switch tubes is reduced, a filter capacitance value can be reduced, the selecting range of the power switch tubes is widened, and after the assisting side edge of the high frequency transformer passes through the cycle converter and an output filter capacitor, a stable sine alternating voltage is obtained. The high frequency isolation type three-level inverter based on the Boost converter has the advantages that the number of power conversion stages is small, the number of power switching devices is small, the voltage stress of the power switch tubes is low, two-way power flow and high frequency electrical isolation can be realized, and the voltage spectral characteristics at the front end of the output filter are good.

Description

technical field [0001] The invention belongs to the technical field of power electronic conversion, in particular to a high-frequency isolated three-level inverter based on a Boost converter. Background technique [0002] At present, the research of power electronics researchers at home and abroad mainly focuses on two-level DC-AC converters such as non-electrically isolated, low-frequency and high-frequency electrically isolated; for the research on multi-level converters, Mainly focus on multi-level DC-DC, AC-AC and DC-AC-DC converters, while the research on multi-level DC-AC converters is very little, and only limited to non-isolated, low frequency or intermediate frequency isolation DC-AC multi-level DC-AC converter, but research on high-frequency isolated multi-level two-stage power conversion inverter is less. [0003] The high-frequency link inverter technology uses a high-frequency pulse wave transformer to replace the low-frequency transformer to transmit energy, o...

AI Technical Summary

Problems solved by technology

[0004] So far, people have made remarkable achievements in the research of buck and buck-boost high-frequency link DC-AC converters, but buck and buck-boost high-frequency link DC-AC converters have large input current ripples, Defects such as low reliability (buck type) and small output capacity (buck-boost) when the load is short-circuited

The research on Boost converters mainly focuses on Boost DC-DC, AC-AC, and AC-DC converters, including non-electrical isolation and electrical isolation. The research on Boost three-level converters mainly focuses on There is no isolation transformer type, but there is little research on Boost three-level converters with isolation transformers, especially Boost three-level inverters with isolation transformers

Images