Dry-type transformers now play a key role in different high-rise buildings, docks, stations, airports and other places that require lighting. Now the industry is very concerned about the dry-type transformer temperature and other aspects of information. Because the dry-type transformer temperature can be said to have a direct impact on the overall equipment operation and work efficiency.
What is a dry-type transformer
Dry type transformers: rely on air convection cooling, generally used for local lighting, electronic circuits and other small-capacity transformers, power systems, general turbine change, boiler change, removal of ash, dust change, desulfurization and other changes are dry change The ratio of change is 6000V/4000 for a load with a rated voltage of 380V.
The cross-flow type cooling fan for the dry type transformer is a type with no guide vane at the inlet and outlet, and is dedicated to the dry cross-flow fan of the dry type transformer. Its main components are: dedicated single-phase or three-phase induction motors with small power induction, cross-flow impellers, casings, and air guides. The temperature control system of dry-type transformers, the safe operation and service life of dry-type transformers depend to a large extent on the safe and reliable insulation of transformer windings. Winding temperature exceeds the insulation resistance temperature to cause insulation damage, which is one of the main reasons leading to the failure of the transformer. It is very important to monitor the temperature of dry-type transformers and the alarm control.
Dry-type transformer temperature
1, the normal working dry-type transformer temperature reaches 95 degrees, it is already considered relatively high. Can no longer increase the load. Low-voltage equipment generally requires that the temperature rise not exceed 60 degrees (ie: ambient temperature + 60 degrees). Excessive temperature will accelerate the aging of the equipment and shorten its service life.
2, the most direct way is: hand touch equipment, can hold on for more than 10 seconds on the line. Can not insist, the temperature is even higher.
3, the transformer can be divided into A level E level B level F level H level according to the heat level
The maximum allowable temperature (°C) 105 120 130 155 180
Winding temperature rise limit (K) 60 75 80 100 125
Performance reference temperature (°C) 80 95 100 120 145
4. According to GB1094.11 dry-type transformer rated operating conditions for the elevation of not more than 100 meters, the hottest month average temperature of 30 degrees Celsius, the highest annual average temperature of 20 degrees, outdoor dry change minimum temperature of -25 degrees, indoor dry change The minimum temperature is -5 degrees.
Dry-type transformer maintenance
1) The inspection is usually conducted every year or longer in a dry and clean place, and every 3 to 6 months when other places such as dust or chemical smoke may enter.
2) If excessive dust accumulation is found during inspection, it must be removed to ensure air circulation and prevent insulation breakdown. Special attention should be paid to cleaning transformer insulators, pads, etc., and use dry compressed air 2 to 5 Atmospheric pressure blows dust into the vented clean air duct.
3) Check whether the fasteners and connectors are loose, whether there are traces of rust or corrosion on the conductive parts, or whether there is traces of creepage and carbonization on the surface of the insulation, and if necessary, take corresponding measures for handling.
4) After the transformer has been running for several years (suggested for five years), the insulation resistance is tested to determine whether the transformer can continue to operate. Generally no other tests are required.
Dry-type transformer structure
1, temperature control system
The safe operation of the dry-type transformer and its service life depend to a large extent on the safe reliability of the transformer winding insulation.
2, cooling method
Dry-type transformer cooling is divided into natural air cooling (AN) and forced air cooling (AF). When air-cooled naturally, the transformer can run continuously for a long period of time under rated capacity. When forced air cooling, the transformer output capacity can be increased by 50%. Applicable to intermittent overload operation, or emergency accident overload operation; due to load overload and impedance voltage increase during overload, in a non-economic operating state, it should not be a long time continuous overload operation.
Summary: The above is the content of the dry-type transformer temperature introduced by Xiao Bian for everyone. I hope that we can effectively help everyone. For more information, please pay attention to this website.
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