How to maintain dry-type transformer

Dry-type transformer is widely used in urban distribution network, high-rise buildings, underground facilities, factory workshops and other places because of its advantages of environmental protection, fire prevention and convenient maintenance. However, in order to ensure its long-term stable operation and prolong its service life, scientific and reasonable maintenance is very important. This paper will introduce the maintenance methods of dry-type transformer in detail from the aspects of daily inspection, cleaning and maintenance, temperature monitoring and environmental management.

A, daily inspection and operation monitoring

Regular inspection is an important means to find potential faults and prevent accidents. Operators should patrol the dry-type transformer every day to check whether its operating state is normal, including whether there is abnormal noise, vibration, odor or local overheating. At the same time, the change of voltage and current should be monitored to ensure that it runs within the rated range. If abnormal conditions such as abnormal sound, overheating or tripping are found, stop the machine for inspection in time, and notify professionals to handle them.

Second, keep the equipment clean

Dust and sundries are easy to accumulate on the surface and ventilation channel of dry-type transformer, which affects the heat dissipation effect and may even cause short circuit or fire. Therefore, dry cloth or soft brush should be used regularly to clean the dust on the transformer surface and vents, and vacuum cleaner can be used if necessary. It is especially important to note that water or wet cloth should not be used for cleaning to prevent the insulation performance from decreasing.

Third, temperature monitoring and heat dissipation management

Because the dry-type transformer relies on air natural cooling or forced air cooling to dissipate heat, it is particularly important to monitor the temperature. During operation, the temperature of key parts such as windings and iron cores should be detected regularly to ensure that it does not exceed the specified value. If the temperature rises abnormally, it is necessary to check whether the ventilation is smooth and whether the fan works normally, and troubleshoot in time. At the same time, the installation site should be well ventilated to avoid the influence of direct sunlight or other heat sources.

Fourth, check the insulation performance

Insulation system of dry-type transformer is directly related to its safe operation. Insulation resistance test should be carried out regularly to judge the insulation status of windings to ground and phase. If the insulation resistance drops, it may mean that it is damp or aging, so it is necessary to take drying measures or replace parts. In addition, it is suggested to install dehumidification equipment for transformers operating in high humidity environment to prevent the insulation performance from decreasing.

Five, check the connection parts and fasteners

During the operation of the transformer, the current passing through the terminals and connectors will generate heat, and long-term operation may lead to loose bolts, resulting in poor contact or even ignition. Therefore, it is necessary to regularly check whether the connection parts are well fastened and whether the terminal has overheating marks. If necessary, re-fasten and apply conductive paste to enhance the conductivity.

Six, reasonable arrangement of load

Dry-type transformers should not be overloaded for a long time, which will not only accelerate the aging of equipment, but also cause safety accidents. The load should be arranged reasonably according to the actual electricity demand to avoid sudden load fluctuation and reduce the impact on the equipment.

Seven, establish and maintain files

Establishing a detailed operation and maintenance file for each dry-type transformer and recording the time and results of each inspection, test and maintenance are helpful to grasp the changing trend of equipment state, find potential problems in advance and make a scientific maintenance plan.

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In a word, the maintenance of dry-type transformer should adhere to the principle of "prevention first, combining prevention with control". Only through scientific management, regular maintenance and timely investigation of hidden dangers can its service life be effectively extended and the safe and stable operation of power system be guaranteed. Enterprises or units should formulate specific maintenance plans according to the equipment model and operating environment, and be implemented by professionals to ensure the quality and effect of maintenance work.