High-reliability double-input seven-level static converter

Abstract

The invention discloses a high-reliability double-input seven-level static converter, and belongs to the technical field of power electronic converters. The converter is composed of two direct-currentvoltage sources (Vin1-Vin2), ten switching tubes (S1-S10), eight diodes (D1-D8), two buffer inductors (L1-L2), a filter inductor (Lo), a filter capacitor (Co) and a load (Zo). According to the invention, different combinations of two direct current voltage sources are fully utilized to obtain seven bridge arm voltages acting on the two ends of an output filter, so that the voltage stress of a power tube is reduced, and the electromagnetic interference caused by dv / dt is reduced; meanwhile, the inverter has the advantages of high integration level, no body diode freewheeling problem, no straight-through risk and the like of a double-input double-buck type inverter; the quasi-constant frequency hysteresis current control strategy is adopted, harmonic waves are easy to filter, and the designdifficulty of the filter is reduced. The converter is particularly suitable for high-reliability high-power application occasions such as aerospace.

Description

technical field [0001] The invention relates to a high-reliability dual-input seven-level static converter and a quasi-constant-frequency hysteresis control strategy thereof, belonging to the technical field of power electronics, in particular to the technical field of DC-AC power conversion. Background technique [0002] Static converters with double buck structure are more and more used because of the advantages of no risk of shoot-through of the bridge arm and the ability to use high-performance independent diodes to replace the freewheeling power switch body diodes, thereby greatly reducing the reverse recovery problem. It is suitable for occasions requiring high reliability such as aerospace, smart grid, and electric vehicles. At the same time, fields with high reliability requirements (such as aerospace) usually contain multiple DC interfaces. How to make full use of the DC interface and improve the power density of static converters has become the focus of more and m...

AI Technical Summary

Problems solved by technology

The patent "Publication No.: CN108448925A" discloses a dual-input five-level inverter, which realizes two independent DC input sources supplying power to AC loads at the same time or in time-sharing with only one inverter, but it does not fully Using multiple level combinations that can be generated by two DC input sources, and the asymmetry of the positive and negative levels lead to an increase in the harmonic content of the output voltage of the inverter bridge arm and uneven heating of the power tube

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