Considerations for switching and protective device combinations in MV/LV transformer station

This document explores how switchgear and protective devices in transformer stations can be optimized to ensure reliable protection against malfunctions, with a particular focus on mitigating switching failures. The goal is to implement protective measures and to propose a new standard concept for transformer stations. The paper examines various protection concepts, comparing options such as fuse switch-disconnectors and circuit breakers with secondary protection. It considers regulatory requirements, including the Heavy Current Ordinance Art. 47 [1] and ESTI 407, alongside operational needs like transformer tripping, protection coordination, and selectivity. The findings underline the significance of robust protection strategies and provide key insights for enhancing safety and reliability in transformer station operations, serving as a foundation for the selection of an optimal protection concept.