Dry-type transformer: It relies on air convection for cooling. It is generally used for local lighting and electronic circuits. Transformers such as machinery and equipment, in power systems, general steam turbine transformers, boiler transformers, ash removal transformers, dust removal transformers, desulfurization transformers, etc. are all dry-type transformers. Simply speaking, dry-type transformers refer to iron cores and windings not impregnated with insulating oil In the transformer. Compared to oil-type transformers, dry-type transformers do not require oil in oil, so there are no problems such as fire, explosion, and pollution. Therefore, electrical codes and regulations do not require dry-type transformers to be placed in separate rooms. Especially for the new series, the loss and noise have been reduced to a new level, and the conditions for placing the transformer and the low-voltage screen in the same distribution room have been created.
Temperature control system of dry type transformer
The safe operation and service life of dry-type transformers largely depend on the safety and reliability of the transformer winding insulation. It is one of the main reasons that the transformer can not work normally because the winding temperature exceeds the insulation withstand temperature and the insulation is damaged. Therefore, the monitoring of the operating temperature of the transformer and its alarm control are very important.
Dry-type transformer protection
According to the characteristics of the use environment and protection requirements, dry-type transformers can choose different shells. The IP23 protective shell is usually selected to prevent solid foreign objects larger than 12mm in diameter and small animals such as rats, snakes, cats, finches and other animals from entering, causing vicious failures such as short-circuit power outages, and providing a safety barrier for live parts. If the transformer must be installed outdoors, an IP23 protective shell can be selected. In addition to the above-mentioned IP20 protection function, it can also prevent water droplets from entering within an angle of 60 ° with the vertical line. However, the IP23 housing will reduce the cooling capacity of the transformer. When selecting it, pay attention to the reduction of its operating capacity.
Cooling method of dry type transformer
The cooling method of dry type transformer is divided into natural air cooling (AN) and forced air cooling (AF). Under natural air cooling, the transformer can continuously run for a long time at the rated capacity. With forced air cooling, the output capacity of the transformer can be increased by 50%. It is suitable for intermittent overload operation or emergency accident overload operation; due to the large increase in load loss and impedance voltage during overload, it is in a non-economic operating state, so it should not be subjected to long-term continuous overload operation.