This book presents the proceedings of the 5th International Colloquium âTransformer Research and Asset Management,â held in Opatija, Croatia, on October 9â12, 2019. The papers chiefly focus on three groups of topics: 1. Numerical Modeling: Electromagnetic fieldsâCoupled fieldsâTransientsâNumerical modeling in design 2. Materials, Components and New Technologies: Insulating materialsâMagnetic materials and transformer noiseâTransformer componentsâNew transformer technologies 3. Transformer Lifecycle Management: Diagnostics and monitoringâFailureâAsset managementâIn-service experiences. The Colloquium was organized by the Croatian National Committee of CIGRE together with the Faculty of Electrical Engineering and Computing in Zagreb and the Centre of Excellence for Transformers