High-frequency isolated type three-level inverter based on push-pull converter

Abstract

The invention provides a high-frequency isolated type three-level inverter based on a push-pull converter. The high-frequency isolated type three-level inverter is composed of an input direct-current power source unit, an input filter, a push-pull three-level inversion unit, a high-frequency transformer, a frequency converter, an output filter and an output alternating current load which are connected in sequence. The input direct-current power source unit is connected with one end of the input filter. The other end of the input filter is connected with one end of the push-pull three-level inversion unit. The other end of the push-pull three-level inversion unit is connected with a primary winding of the high-frequency transformer. A secondary winding of the high-frequency transformer is connected with the input end of the frequency converter. The output end of the frequency converter is connected with the input end of the output filter. The output end of the output filter is connected with the output alternating current load. The high-frequency isolated type three-level inverter has the advantages that the number of levels of power conversion is small, few power switch elements exist, voltage stress of a power switch tube is low, bidirectional power current and high-frequency electric isolation are achieved, and the voltage spectral characteristic of the front end of the output filter is 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 push-pull converter. Background technique [0002] Direct-to-AC (DC-AC) conversion technology is a static conversion technology that uses power semiconductor devices to convert DC power into constant-voltage and constant-frequency AC power. The constant-voltage and constant-frequency AC can be used for AC loads or with AC The use of grid-connected power generation is now widely used in many aspects such as industrial production and scientific research. The DC-AC converter is the key to realize the static conversion technology. At present, the research and development of DC-AC converters at home and abroad mainly focus on two-level DC-AC converters and multi-level DC-DC, DC-AC and AC-DC converters. The research on converters, especially inverters for high-frequency isolated multi-level two-stage power ...

AI Technical Summary

Problems solved by technology

[0005] In view of the problems of high voltage stress at both ends of the switching tube and low power factor on the input side of the multi-level inverter in the prior art, the purpose of the present invention is to provide a high-frequency isolated three-level inverter based on a push-pull converter It has two-stage power conversion (DC DC-high frequency AC HFAC-low frequency AC LFAC), bidirectional power flow, good spectral characteristics of output filter front-end voltage, high power density, low voltage stress of switching devices, and can realize AC Load and DC power high-frequency electrical isolation

Images