Located in the main production factory of Company with closed synchronous production line for dry transformer
Equipped with the most advanced automatic equipment and technology to improve the quality of products such as: wave folding equipment, automatic welder for casing of dry transformer, sheet metal mixing equipment, sheet metal cutting equipment, copper foil wrapping equipment, automatic winding machine, vacuum drying equipment, oil refining equipment, electrostatic cleaning and painting systems, in addition, there is a laboratory for comprehensive evaluation of products
Manufacture of transformer core
Plate of dry transformer is made of high quality cold rolled dynamo sheet
Sheet metal plate is split automatic splitting machine, then the plate shall be cut under 90 °, 45 ° angle, cut in the form of ladder by the cross-cut machine which is automatically controlled. Sheet metal plate is processed by modern equipment and technology to reach extremely high precision and minimize burr and no-load losses, no-load currents and machine noise.
Manufacture of coil of transformer
Low pressure coil
The low pressure coil of dry transformer is made of copper foil, rolled on the copper foil rolling machine in order to decrease the loss due to short circuit and remove the axial force when occurring the short circuit
Manufacture of casing of transformers
The casing of dry transformer has the structure of seam welding or wave folding as required by the customer. In recent years, sealed transformers have been designed, manufactured and used widely in the country as well as abroad due to the ability to withstand the expansion of the bridge.
The sealed machine shall prevent the insulation of the dry transformers from the decrease and minimum the maintenance for machine
HEM has the largest synchronous line for manufacturing casing of dry transformer and wave folding equipment for transformer in Vietnam that is automatically controlled for folding fins and sealing fins. The wave folding casing plates are sealed into a barrel, the lid of machine after processing and welding of parts attached to the lid, shall be put into the peening machine for cleaning and painted the protective coating in electrostatic painting system.
Quality controlling and testing
The production of production process of dry transformers managed according to standard ISO 9001-2008. The products’ quality is rated in laboratory for dry transformer by advanced equipment. The dry transformers are tested under the following steps: • Measure the dry transformer ratio • Determine polarity and connection thermal visual connected • Measure DC resistance with high-voltage coil and low-voltage coil • Measure the no-load losses • Measure no load current • Check the insulation between turns • Measure short-circuit losses • Measure short-circuit voltage • Test High-voltage according to standard
Check other parameters as required by the customers (measure the increase off temperature of dry transformer coil, noise level, test short circuit, test the insulation and oil index, test impulse voltage resistance