Auxiliary resonant conversion pole T-type three-level soft switch inversion circuit and modulation method thereof

Abstract

The invention provides an auxiliary resonant conversion pole T-type three-level soft switch inversion circuit and a modulation method thereof. The circuit comprises a T-type main inversion circuit, anauxiliary resonant conversion circuit, a filtering circuit and a load, wherein the T-type main inversion circuit comprises four switch tubes and two same support capacitors, the four switch tubes areprovided with diodes which are reversely connected in parallel, the auxiliary resonant conversion circuit comprises two auxiliary switch tubes, four resonant capacitors and a resonant inductor, the two auxiliary switch tubes are provided with diodes which are reversely connected in parallel, and the filtering circuit is an LC filtering circuit. According to the modulation method provided by the invention, zero-voltage on/off of the main switch tube and zero-current on/off of the auxiliary switch tube can be achieved. By the circuit, the T-type three-level hard switch loss can be reduced, thesystem efficiency is improved, and the electromagnetic interference is reduced.

Description

Technical field [0001] The present invention relates to the technical field of power electronics, in particular to an auxiliary resonance conversion pole T-type three-level soft switching inverter circuit and a modulation method. Background technique [0002] With the rapid development of power electronics technology, people's demand for high-frequency, miniaturized, lightweight inverters with high power and high power density is also increasing. However, as the switching frequency increases, the use of conventional pulse width modulation technology will face many problems. On the one hand, the switching loss of the switch tube will increase, and on the other hand, the system will generate electromagnetic interference (EMI). [0003] In order to solve the above problems, since the 1980s, soft switching technology has been in-depth research, and various topological structures and modulation strategies have been continuously optimized and improved. The soft switching technology uses...

AI Technical Summary

Problems solved by technology

[0009] 1. The added double auxiliary resonant commutation circuit uses more auxiliary switching tubes and auxiliary diodes, which increases the hardware cost;

[0010] 2. There are many auxiliary switching tubes, which increases the difficulty of the modulation method of the auxiliary switching tubes;

[0011] 3. The inverter circuit is aimed at two-level circuits, and it is difficult to apply it to three-level circuits

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