Resilience solutions for bypassing power transformers and recommendations of site commissioning tests

Considering the dependency of electricity in today's economic environment, grid resilience is a highly discussed topic today. Several major outages have taken place over the last decade, prompting electric utilities to search for viable solutions to ensure the stability of their grids. Reasons for power outages are manifold, ranging from operational issues to forced physical impacts or natural disasters. The costs of such an outage for the electric power industry and the society can be tremendous. Because of the ample nature of grid resilience requirements associated to power transformers, this paper studies three fields of action which are key to address resiliency: Prevention, Protection and Reaction. Beside these three pillars the paper focus on two case studies for transmission transformers and presents a new solution for generator-step-up transformers to react quickly when rapid replacement needs to be carried out. This includes the necessity to plan in details the installation and commissioning site tests which are addressed in this paper considering new approaches.