Increased reliability of smart distribution transformers for efficient operation of LV distribution electric grids

Smart distribution transformers with on-load tap changers (OLTC) and real-time sensors have been implemented to address voltage fluctuations caused by prosumers and electric vehicles in low-voltage (LV) networks. Since this technology is new, it is crucial to ensure its reliability throughout its lifespan. To achieve this, new Stress Approval Tests have been introduced, including 500,000 operations under nominal voltage conditions. Additionally, 200,000 operations have been performed at nominal current. After these operations, additional tests were conducted to ensure the integrity of the transformer. These tests were carried out in manufacturing laboratories and in the Smart Grid Laboratory, UDEX.