Oil-immersed transformer with insulating oil as cooling and insulating medium, there are many safety hazards: once the leakage occurs, the insulating oil will not only pollute the soil and water, its expensive cleanup and maintenance costs can reach hundreds of thousands of yuan; mineral oil ignition point of only 160 ℃, in the electrical short-circuit sparks easily triggered combustion or even an explosion; when the operating temperature exceeds 105 ℃, the insulating oil decomposition of gas such as acetylene Toxicity, and the oil body moisture will lead to a sharp decline in insulation performance, a direct threat to the safe operation of equipment.
In contrast, dry-type transformers, such as mining transformer, explosion proof transformer, 100 kva transformer 3 phase adopts all-solid-state structure, fundamentally avoid the risk of oil leakage. The epoxy resin coating on the coil surface reaches UL94 V0 flame retardant level, with self-extinguishing characteristics; H-class insulating material can be sustained and stable operation under 180℃ high temperature environment; epoxy resin sealing process makes its waterproof level reach IP65 standard, which significantly improves the ability of moisture and dirt resistance.
In the electrical energy conversion mechanism, to 10kV step-down to 400V typical applications, for example, dry-type transformer through the principle of electromagnetic induction to achieve high efficiency transformer. When the high-voltage power input high-voltage coil, alternating current excitation of periodic changes in the magnetic field; silicon steel sheet stacked iron core to build a low reluctance path, the magnetic field will be quickly conducted to the low-voltage coils; according to the law of electromagnetic induction, the low-voltage coils through the cutting of magnetic lines of inductance to produce induced electromotive force, the voltage conversion ratio strictly follow the coil turns ratio. In this process, the epoxy resin coating plays a dual role: on the one hand, it serves as an electrical insulating layer to ensure the electrical isolation of the high and low voltage sides; on the other hand, through the high thermal conductivity, it can quickly transfer the heat generated by the coil operation to the air, and together with the natural convection or forced air-cooling system, it can maintain a stable operating temperature of the equipment.