Technical application characteristics of Encapsulated Transformer
(1) Good gas performance, low partial discharge value: in the transformer insulation structure, how many local insulation weaknesses, it will first occur under the action of the electric field discharge, but not immediately the formation of the entire insulation penetration breakdown, it may occur on the surface of the insulator or internal, that is, partial discharge. However, most of the damage or local aging of electrical insulation starts from partial discharge, and its harm is prominent in the rapid reduction of insulation life, which ultimately affects the safe operation. Due to its unique structure (high and low voltage windings are all wound with copper strip (foil)) and its advanced manufacturing technology (high and low voltage windings are all poured epoxy resin in vacuum and cured), the partial discharge value of dry transformers is low.
(2) Strong lightning impact resistance: Because the high and low voltage windings are all made of copper strip (foil) wound, the interlayer voltage is low and the capacitance is large. The initial voltage distribution of the foil winding is close to linear, so its lightning impact resistance is strong.
(3) Strong short-circuit resistance: because the high and low voltage winding reactance height is the same, no spiral Angle phenomenon, ampere-turns balance between coils, high and low voltage winding due to short circuit caused by the axial force is almost zero, so its strong short-circuit resistance.
(4) Good anti-cracking performance: dry transformer adopts epoxy resin "thin insulation (1-3mm) technology", which meets the occasions of low temperature, high temperature and wide range of temperature changes, meets the requirements of anti-cracking after long-term operation, and solves the cracking problem difficult to be solved by "thick insulation (6mm) technology", so that dry transformer is technically reliable.
(5) Strong over load capacity: if the load loss of the transformer with the same capacity is equal, the area of copper foil will increase correspondingly than that of the copper conductor. After the volume increases, the amount of filler resin will increase correspondingly, so the winding heat capacity is large and the transformer short-term overload capacity is strong.
(6) Good flame retardant performance: the epoxy resin vacuum casting process has no environmental pollution, conducive to environmental protection, the transformer has maintenance-free, moisture-proof, heat-dampness resistance, flame retardant and self-extinguishing characteristics, suitable for a variety of environment and bad conditions.
(7) Low loss, low noise: the core is usually made of mineral oxide insulation of high quality cold rolled silicon steel sheet, through advanced processing technology, the loss level and no-load current is reduced to a minimum, and a very low noise level. At the same time, the assembled iron core is sealed with F grade resin paint on its surface to prevent dust, corrosion, smoke and rust.
(8) High temperature resistance grade: epoxy resin dry transformer belongs to F or H class insulation, long-term safe operation at 155℃ or 180℃ high temperature. In the same capacity, its small size, light weight, can save installation costs.
(9) Relevant technical specifications: ① Capacity ≤10000KVA; Voltage ≤35KV; ③ Insulation grade F or H.
