This article proposes a three-phase four-wire ac–dc–ac converter with legs shared between grid and load sides. This topology is suitable for operation as uninterruptible power supply and unified power quality conditioner. Also, two scenarios of the converter are considered, first, load and grid voltages with same amplitude with possibility to compensate grid-voltage swells, and second, grid voltage with twice the amplitude of load. Converter model, pulsewidth modulation, control strategies, and passive elements design are developed. Comparisons between conventional and proposed topologies in terms of harmonic distortion and semiconductor losses are carried out. The proposed converter is suitable for operation in low-voltage high-power applications, presenting lower conduction losses than the considered conventional topologies.

中文翻译：

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具有共用支路的三相四线 AC-DC-AC 转换器

本文提出了一种三相四线 AC-DC-AC 转换器，其支路在电网侧和负载侧之间共享。这种拓扑适合作为不间断电源和统一电能质量调节器运行。此外，还考虑了转换器的两种情况，第一，具有相同幅度的负载和电网电压，可以补偿电网电压骤升，第二，具有两倍负载幅度的电网电压。开发了转换器模型、脉宽调制、控制策略和无源元件设计。在谐波失真和半导体损耗方面对传统拓扑和建议拓扑进行了比较。所提出的转换器适用于低压大功率应用，与所考虑的传统拓扑相比，其传导损耗更低。