Introduction of Mine Flameproof Dry type Transformer
2022-11-10
Mine flameproof dry-type transformer is used in places with explosion risk in the mine. This type of transformer is mostly made of dry type, and its main structural feature is that all the joint surfaces of the box shell are made according to the requirements of explosion-proof, and can withstand the internal pressure of 0.8 MPa.
The physical structure editing includes: the main body of the mining transformer, the high voltage head at the incoming line end of the high voltage side (used to control the on-off of the incoming line end of the high voltage side, with a protection circuit) and the low voltage head at the outgoing line end of the low voltage side (used to control the on-off of the incoming line end of the low voltage side, with a protection circuit)
Insulation Edit solid insulation. The solid insulation of epoxy resin cast dry-type transformer consists of cast resin+resin impregnated materials (such as glass fiber, film, etc.). It mainly includes the insulation inside the winding (such as turn insulation), the insulation between sections of segmented layered windings, and the insulation of windings and leads. As shown in Figure A, the serious problem of solid insulation is the local discharge caused by the occurrence of holes in the casting parts or cracks during operation, which will lead to the long-term aging of insulation and breakdown.
Composite insulation (air+solid) mainly includes insulation between HV and LV windings, insulation between HV winding and iron core (insulation to ground) and insulation between HV winding and winding winding (insulation between phases). As shown in Figure B, it is essentially equivalent to the main insulation of oil immersed transformer. The dielectric constant ratio of air to epoxy resin is about 1:3.5, Therefore, the field strength acting on the air gap will be higher than that of the epoxy resin, but the electrical strength of the epoxy resin is much higher than that of the air, so the overall insulation strength will depend on the air gap.
Insulation along the surface, insulation between terminals on the pouring surface of the insulating paper along the surface, and insulation between the pouring winding and the surface of the supporting insulating parts, as shown in Figure C, the problem of insulation along the surface is mainly the discharge along the surface. At this time, the surface pollution and moisture absorption have a great impact on it
The capacity of mining dry-type transformer with heat resistance rating is generally 4 KVA and 2.5 KVA, which are specially used for power supply of electric drill, lighting, signal and other equipment. Its incoming and outgoing lines are led out by cables through outlet sleeves. There are 380 V and 660 V voltages on the primary side; The secondary side voltage is generally 133 V. Flameproof transformers with a capacity of more than 100 KVA are often combined with flame-proof switch boxes to form flame-proof complete mobile substations. Its output voltages are 400V, 690V and 1200V to meet the needs of mine electrical equipment. In order to adapt to tunnel transportation, the transformer structure height should be low. In this way, the iron column diameter can be larger, and cold rolled silicon steel sheets are generally used. 100 KVA and above are usually Class H insulation.
Application: 1. In the emergency state where emergency power supply for emergency rescue and relief is required due to sudden natural disasters or equipment accidents, if the system has no spare capacity, it can replace a conventional substation in whole or in part for power supply.
2. In the power supply of the mining area, the mobile substation can meet the requirements of large capacity and high voltage power supply for heavy mechanized coal mining units, and can be promoted together with the mining face, which can better solve the problem of excessive power supply voltage drop or insufficient short circuit protection sensitivity.
3. When the power demand is growing rapidly, the power supply distance is relatively far, which exceeds the pre planned power construction plan, and it is difficult to establish a substation, it will be put into operation as a temporary substation to ease the tension of power supply, such as the coal mine excavation extension project.
4. The substation construction in a certain area is suspended due to fund shortage or other reasons, and is put into operation as a temporary substation.
5. The mining mobile substation can not only be used as the power supply equipment under the coal mine, but also be extended to the ground power supply system, which is universal above and below the mine, further improving the comprehensive utilization rate of equipment; At the same time, it can save investment in land acquisition, civil engineering and substation equipment installation, and reduce operating costs
Qingdao Hengfengyou Electric Group, is an electrical enterprise with transmission and distribution industry as its main business, integrating product research and development, manufacturing and trade. Designated suppliers for the world's top 500 enterprises.Its main products include oil-immersed transformer,dry-type transformer,electric furnace transformer,mining transformer ,rectifier transformer .It has been successfully sold to more than 50 countries around the world. Product certification is complete. Hengfengyou Electric will provide you with the best electrical product solutions. 【https://www.hengfengyou-electric.com ； sales@hengfengyou-electric.com ； WhatsApp：+86158 5325 2696（Jack） 】
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