Mining transformers are special transformers used in mining environments, and their selection needs to fully consider the particularity of the mining environment (high humidity, high dust, flammable and explosive gas, vibration, etc.). The core selection parameters are as follows:

　　1. Rated capacity

　　It needs to be determined according to the total power of all electrical equipment in the mining working face, and a margin of 15%~25% should be reserved to deal with the possible overload situation of the equipment

　　If there are large starting power equipment (such as mining scraper conveyors, shearers), it is necessary to additionally consider the impact of the starting current on the transformer

　　2. Rated voltage level

　　It needs to match the power supply voltage of the mine and the rated voltage of the mining electrical equipment:

　　The common primary side voltage is 6kV, 10kV (matching the mine's highvoltage power supply system)

　　The common secondary side voltage is 380V, 660V, 1140V (matching the voltage requirements of different mining equipment)

　　3. Insulation level

　　It needs to adapt to the high humidity and dust environment of the mine, and it is generally required to reach Class F or Class H insulation

　　The insulation structure needs to have good moisture resistance, dust resistance and anticorrosion performance

　　4. Protection level

　　At least reach IP54 (prevent the entry of dust that affects normal operation, and prevent the splashing of water from all directions from causing harm), and in the working face with more water and dust, it is recommended to choose IP55 or higher protection level

　　5. Flame retardant and explosionproof performance

　　In mines with explosive gas (such as gas mines), it is necessary to select explosionproof mining transformers that meet the requirements of GB3836 series standards, and the explosionproof grade is generally ExdI or ExibI

　　The insulating materials and insulating oil (for oilimmersed mining transformers) need to have good flame retardant performance

　　6. Cooling method

　　Drytype mining transformers are generally aircooled (AN), which is more suitable for the narrow space of the mine

　　Oilimmersed mining transformers are generally oilair natural cooling (ONAN), and some special models will use forced oil circulation cooling

　　7. Antivibration performance

　　The structure needs to have good antivibration performance to adapt to the vibration generated by mining equipment operation and mine blasting