High-frequency isolation type three-level inverter

Abstract

The invention discloses a high-frequency isolation type three-level inverter. The high-frequency isolation type three-level inverter comprises an input direct current power supply, voltage sharing capacitors, a full-bridge current source type high-frequency isolation type three-level conversion unit, a cycle converter, an output filter and an output alternating current load which are connected insequence; on the basis of the conventional full-bridge current source type inverter, two voltage sharing capacitors are connected at the two ends of an input direct current voltage source in parallel,so that the front end of a transformer can generate three levels of U, U / 2, -N<1>U<0> / N<2>, thereby lowering voltage stress of a switching tube, and expanding the application range of the current source type high-frequency isolation inverter. The high-frequency isolation type three-level inverter has the advantages of two-stage power conversion (direct current DC-high freqeucny alternatingcurrent HFAC-low freqeucny alternating current LFAC), bidirectional power flow, low voltage stress of the switching device, high voltage spectral characteristic at the front end of the output filter,small size of the output filter, relatively high power density, and capability of realizing high frequency electrical isolation of an alternating current load and a direct current power supply.

Description

technical field [0001] The invention belongs to the technical field of power electronic conversion, in particular to a full-bridge current source type 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...

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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