ConstructionThe Energy Power to make a Difference
The cut of the core sheets and the material of the ferromagnetic core are optimized according to the desired no-load characteristics and the specified noise level. Extensive rationalization of the shape and the clamping devices enables us to produce a core with minimum losses and dimensions. Thismethodology optimizes the consumption of both materials and energy, bringing benefits to the user, the environment and the manufacturer.
The core has to be constructed in such a way as tolimit the energy losses caused by eddy currents and hysteresis to a minimum. This is achieved by the use of silicon steel, a special soft steel with a 3.5% silicon content, which is characterized by low hysteresis losses and high resistivity. The core consists of a series of laminations made from very thin sheets of steel insulated on both sides by an oxide layer.
The reactive power dissipation can be lowered by limiting flux disturbances and minimizing air gaps in the joints between the core legs and the yokes. This is achieved by overlapping the core sheets while stacking them.
The ferromagnetic core
The construction of a transformer comprises two active components: the ferromagnetic core and the windings. Within the transformer industry, the core and windings together are normally referred to as the “active part”.
The passive part of a transformer is the cooling system, consisting of the tank and the cooling liquid (mineral Oil).
The core is constructed using thin sheets of cold-rolled grain-oriented magnetic silicon steel insulated on both sides. Conventional grainoriented steel (CRGO steel) is used for transformers with normal no-load loss characteristics, while transformers with reduced no-load losses are built using higher-quality HiB steel (usually laser treated). These steel sheets are 0.30 mm, 0.27 mm or 0.23 mm thick.