sic high voltage switch and silicon igbt hybrid three-phase four-wire high voltage converter

Abstract

The invention provides an SiC high-voltage switch and silicon IGBT mixed type three-phase four-wire high-voltage converter which comprises 2N silicon IGBT low-voltage module units, six SiC high-voltage switches and eight bridge arm inductors. The phase a, the phase b and the phase c of the mixed type three-phase four-wire high-voltage converter are the same in structure, an upper bridge arm is formed by a high-voltage switch and a bridge arm inductor in a series-connecting mode. A lower bridge arm is formed by a bridge arm inductor and a high-voltage switch in a series-connecting mode. Then, the upper bridge arm and the lower bridge arm are connected in series. The connecting point of the upper bridge arm inductor and the lower bridge arm inductor forms an alternating-current output end of a bridge arm with a corresponding phase. An upper bridge arm of a phase o is formed by N low-voltage module units and a bridge arm inductor in a series-connecting mode in sequence, a lower bridge arm is formed by a bridge arm inductor and N low-voltage module units in a series-connecting mode in sequence, then the upper bridge arm and the lower bridge arm are connected in series, and the connecting point of the upper bridge arm inductor and the lower bridge arm inductor forms a middle wire end. The alternating-current output end is connected to load in a three-phase star-shaped connecting mode, the middle wire end is connected to the middle point of the load, by controlling output of the middle wire end, load voltages can generate a sine multi-level phenomenon, and harmonic waves are reduced.

Description

technical field [0001] The invention belongs to the field of power electronic converters or high-voltage applications, and relates to the topology structure of a SiC high-voltage switch and a silicon IGBT hybrid three-phase four-wire high-voltage converter. Background technique [0002] One of the key technologies to realize high-voltage high-power converters is the high-power converter topology. In recent decades, in-depth research on high-voltage large-capacity converters has been carried out internationally, and many meaningful high-voltage large-capacity topologies have been proposed. Module combined multi-level converter, MMC converter, is currently the preferred converter for high-voltage power conversion. Its advantage is that each phase bridge arm is composed of multiple identical modular power units and two bridge arm inductors in series according to the voltage level. , to achieve a high degree of modularization, and has more obvious advantages than general multi-l...

AI Technical Summary

Problems solved by technology

However, the price of SiC power switching devices is relatively high, and all of them will affect the cost performance of high-voltage converters. For this reason, this invention proposes a SiC high-voltage switch and silicon IGBT hybrid three-phase four-wire high-voltage converter, which can reduce high-voltage conversion. The cost of the device can be reduced, and the circuit composed of silicon IGBT can be used to realize multi-level control

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