Three-phase transformers

Production of three-phase transformers

The S.V.T.I. three-phase transformers and three-phase autotransformers are designed and manufactured with low-loss choice materials, and with various structuring of magnetic cores according to the technical specifications of the client (sheets woven with joints interspersed with 90º and 45º cuts, cores with planed joints, with air gap, etc.).

The energy of a three-phase system can be transformed both through three single-phase transformers suitably connected, thus creating a three-phase base, or by means of a three-phase transformer having power equal to the sum of the powers of the three single-phases. Thus, the three-phase transformers are to be considered as three independent electric coils, each single-phase formed by a phase. The three-phase autotransformers, contrarily to the three-phase transformers, have a single coil and therefore do not have the galvanic separation between the two coals. Upon specific request, different kinds of protection can be created,also being the only the output terminals and, in addition, additional equipment for thermal protection and/or of movement and for handling can be supplied upon specific request.
Precise and binding testing ensure a high degree of safety and reliability for each individual transformer produced, in accordance with applicable national and international regulations.


BT power transformers and auto-transformers;

galvanic isolation transformers with high insulation;

Three-phase, six-phase and twelve-phase rectifier transformers with three and five column cores;

Transformers for output inverters;

Transformers and autotransformers with series and/or integrated parallel inductors;

Converter transformers from three-phase system to single-phase (also balanced);

Conversion transformers from a three-phase system to a two-phase (Scott System);

Autotransformers for starting three-phase asynchronous motors.

S.V.T.I. production includes both three-phase inductances and reactors; those with a magnetic core have grain-oriented lamination even from lower powers, with the air gap always split so as to considerably reduce the noise and loss.

A thorough pre-testing and definitive final testing provide a precise and safe inductive product for any application.


Three-phase filters reactors and levelling reactor both in iron and air;

Three-phase switching and damping reactances;

Three-phase reactor block for rephasing systems;

Three-phase reactor without magnetic core for short-circuit current limiting;

Three-phase reactors for asynchronous motors starting.


S.V.T.I.three-phase transformers and three-phase autotransformers are designed and manufactured with top-quality materials, electrolytic conductors in copper wire, ribbon cable and aluminium, insulated with high dielectric and thermal properties (classes F and H), impregnated with paint or epoxy resins, with extremely sturdy and safe mechanical support suitable for any installation requirement. The three-phase three-phase transformers and autotransformers S.V.T.I. They can be supplied complete with accessories and custom wiring, based on the specific needs of the customer. On request, the metallic box can be supplied to shield the machine with varying degrees of protection. The quality of S.V.T.I. single-phase transformers and single-phase autotransformers is verified across various levels: each implementation phase is checked, from the initial winding to the final test of the transformer itself. Upon conclusion of production, each transformer is tested 100%. In this way, the electromagnetic performance and safety degree is certified for each transformer. The pre-testing as well as the final testing is carried out in accordance with applicable CEI EN 61558 - CEI 96.7 - 96.8 - CE regulations applicable, according to the type of transformer and its utilisation. The careful overseeing of production processes and customisation of testing with dedicated and specially-designed equipment guarantees maximum reliability for S.V.T.I. transformers. Also to note is that the S.V.T.I. single-phase transformers and single-phase autotransformers are made with automated machinery to ensure maximum reliability and repeatability of the electric tolerance parameters. S.V.T.I. designs and develops different types of three-phase transformers and three-phase autotransformers designed and customised according to the needs of the end user by maximising performance and preventing any kind of problem.
S.V.T.I. three-phase transformers and three-phase autotransformers cover a wide range of applications with dimensional and technical characteristics, ranging from standard to more complex customisation. S.V.T.I. supports its customers from the design and customisation of three-phase transformers and three-phase autotransformers, so as to guarantee the best results in economic and technical performance terms.
S.V.T.I. electrical transformers are applied to various sectors, such as that of control panels, home automation and more generally in all applications requiring a variation of voltage with respect to that fed to the transformer itself.


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