High-frequency isolation three-level inverter

Abstract

The invention provides a high-frequency isolation three-level inverter. The high-frequency isolation three-level inverter comprises an input direct-current power supply, a voltage dividing capacitor, a high-frequency isolation Buck-Boost type three-level conversion unit, a cycle converter, an output filter and an output alternating-current load which are connected with one another. According to the converter, on the basis of a traditional full-bridge high-frequency isolation Buck-Boost type inverter, two capacitors are connected to the two ends of an input direct-current voltage source in parallel for voltage division, so that three levels can be generated at the front end of a transformer, the voltage stress of a switching tube is reduced, and the application range of the high-frequency isolation Buck-Boost type inverter is widened. The high-frequency isolation three-level inverter has the advantages of two-stage power conversion (direct current (DC)-high frequency alternating current (HFAC)-low frequency alternating current (LFAC), bidirectional power flow, low voltage stress of a switching device, good voltage spectrum characteristic at the front end of the output filter, small size of the output filter, relatively high power density, capability of realizing high-frequency electrical isolation of an alternating current load and a direct current power supply, suitability for a micro-grid and the like.

Description

technical field [0001] The invention belongs to the field of power electronic conversion, in particular to a high-frequency isolated three-level inverter. Background technique [0002] Direct-to-AC (DC-AC) conversion technology is a static converter device that uses power semiconductor devices to convert DC power into constant-voltage and constant-frequency AC power. It is used in national defense, industrial and mining enterprises, scientific research institutes and daily life. With the development and utilization of new energy sources, direct-to-alternating current (DC-AC) conversion technology has more and more applications in the transformation of electric energy converted from other new energy sources such as batteries, solar cells, and fuel cells into alternating current energy and grid-connected power generation. application. [0003] So far, the research of power electronics researchers at home and abroad has mainly focused on non-electrically isolated DC-AC conver...

AI Technical Summary

Problems solved by technology

However, due to the limitation of the flyback topology and the shortcomings of the two-level circuit itself, the switching tube of the inverter has low power and low voltage withstand capability, so it can only be used in occasions with low voltage and power.

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