Main circuit topology of tri-electrical-level double-dropping type semi-bridge inverter and control method thereof

Abstract

The present invention is one inverter includes one step-down modulating and filtering output circuit comprising one power source, two power switching transistors, filtering inductor, filtering capacitor and two freewheeling diodes; and one other step-down modulating and filtering output circuit comprising one other power source, two other power switching transistors, one other filtering inductor, the said filtering capacitor and two other freewheeling diodes. In the circuit, each power switching transistors has a voltage stress only one time that of the output voltage, and from the bridge arm, three-state voltage waveform may be output, so that low voltage HF power transistors may be used for high switching frequency, reduced volume and weight and fast dynamic response. The present invention proposes no-bias current half-period operation mode of the inverter with optimized operation efficiency and corresponding control method.

Description

Technical field: [0001] The invention relates to a main circuit topology of a three-level double-buck half-bridge inverter and a control method thereof. Background technique: [0002] With the development of high-frequency power devices, the switching frequency of inverters has been greatly increased, and the development of AC power sources such as aviation power supplies, UPS systems, and high-performance motor drives has put forward higher requirements for the performance of inverters. How to achieve high frequency inverter while ensuring high efficiency is the key issue of current research. Soft switching technology can effectively reduce the switching loss of the converter. In the past ten years, domestic and foreign scholars have done a lot of research on the soft switching problem of inverters, and have obtained many valuable research results. There are mainly polar resonant inverters, resonant DC high frequency link inverters, resonant buffer network inverters and s...

AI Technical Summary

Problems solved by technology

But at present, these circuits are only used in high-voltage and high-power occasions, and high-voltage devices such as IGBTs must be used, and the high-frequency performance is limited.

The double step-down half-bridge inverter is composed of two active tubes, the modulation waveform level of the bridge arm is two levels, and the power tube has no direct problem, but the voltage stress of each power tube in this circuit is twice Output voltage; the full-bridge inverter has four active tubes, the modulation waveform level of the bridge arm is three-level, the voltage stress of each power tube is double the output voltage, but the power tube has a straight-through problem

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