面向变电站固态变压器的综合保护方案

This paper proposes a novel protection setup for the solid-state transformer (SST) for its reliable and healthy operation in power grids. The protection configuration for the conventional power transformer in IEEE Std C37.91-2021 and the country-specific grid codes are no longer relevant to the SST because of its diverse topologies and functionalities. Furthermore, most of the protection configuration for the SST is designed considering its standalone operation. In this context, this paper proposes a protection system for the SST for its operation in a substation within a power grid, rather than focusing solely on its protection for the standalone operation. The potential faults and their recommended protection functions have been proposed compared with the existing protection setup utilized for the conventional power transformer (CPT). Additionally, the paper details the differential currents required to activate the differential protection for internal faults for different operating modes of the SST. The proposed protection scheme incorporates several protection features aimed at holistic protection of the SST, and its effectiveness has been validated at the system level by employing an IEEE-13 node test feeder.