Research and Application of Redundancy Method of Black Module in SVG Device

The stable operation of SVG device is closely related to the H-bridge submodules. In electric power industry, the standard practice to deal with a fault submodule is to bypass it. However, the fault submodule may become black modules due to various reasons, so that their status is uncertain and cannot be bypassed. To solve this problem, a new H-bridge cascaded SVG black module redundancy scheme is proposed in this paper, which can rapidly start redundancy logic when black module occurs and bypass them accurately. This paper analyzes the SVG communication architecture, topology and charging and discharging process of H-bridge, by which the black module redundancy method for new H-bridge cascade SVG topology is obtained. The new redundancy method has been verified through RTDS hardware-in-the-loop simulation and engineering applications, which fully proves its rapid, effective and reliable performance. The application of this redundancy method reduces the probability of the SVG device tripping due to single submodule failure, and therefore improves the stability of the device operation.