Half-bridge five-electrical-level inverter and high-frequency insulation-type half-bridge five-electrical-level inverter

Abstract

The invention discloses a half-bridge five-electrical-level inverter and a high-frequency insulation-type half-bridge five-electrical-level inverter. A construction technique of a clamping-type multi-electrical-level circuit is applied to a Buck-type inverter; a clamping diode in a diode clamping-type three-electrical-level circuit is replaced into a power switch tube, so that a high-frequency insulation transformer primary side winding can obtain the direct-current power supply voltage, and meanwhile, the power switch tube also can play a role in clamping a diode, so that five types of electrical levels of +Ui, -Ui, +Ui / 2, -Ui / 2, and 0 can be obtained on the primary side winding; the five types of electrical level also can be inducted on an auxiliary side winding; and the output five electrical levels obtains the stable sine alternating-current voltage through the filtering of a cyclic wave converter and an output filter. According to the invention, the power conversion number of stages is less; power switch devices are less; the power switch tube voltage stress is low; the selection range of the power switch tube is widened; the bidirectional power flow can be realized; the electrical insulation property is provided; the voltage spectrum property at the front end of the output filter is good; and the volume and the weight can be reduced.

Description

technical field [0001] The invention belongs to the technical field of power electronic conversion, in particular to a half-bridge five-level inverter and its application. Background technique [0002] Direct-to-AC (DC-AC) conversion technology is a conversion technology that uses power semiconductor devices to convert DC power into AC power. It is widely used in national defense, industrial and mining enterprises, scientific research institutes, university laboratories and daily life. . [0003] So far, research on DC-AC converters by power electronics researchers at home and abroad has mainly focused on non-electrically isolated, low-frequency and high-frequency electrically isolated two-level DC-AC converters; for multi-level converters The research mainly focuses on multi-level DC-DC, DC-AC and AC-DC converters, while the research on multi-level DC-AC converters is very little, and is only limited to non-isolated, low-frequency or intermediate-frequency isolated DC-AC ...

AI Technical Summary

Problems solved by technology

However, the diode-clamped and capacitor-clamped multi-level multi-point flat inverter technologies have defects such as single topology and no electrical isolation: the cascaded multi-level inverter technology with independent DC power supply has complicated circuit topology on the input side Low power factor, low conversion efficiency, low power density and other defects;

It only reduces the voltage stress of the switching tube in the DC / DC converter with high-frequency electrical isolation, but does not really realize multi-level at the front end of the output filter inductor, and does not reduce the voltage stress of the switching tube of the Buck inverter bridge. , the output filter inductor and capacitor values ​​have not been reduced

Moreover, this multi-level topology is proposed on the basis of the unidirectional Buck-type high-frequency link inverter. Due to the inherent defects of the unidirectional Buck-type high-frequency link inverter, this series of high-frequency isolation types are mostly Level topology applications are limited

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