Standard temperature of oil-immersed transformer

The temperature standard value of the oil-immersed transformer mainly involves the upper limit value of its winding temperature and oil temperature, which is crucial to ensure the normal operation of the transformer and extend its service life. The following is a detailed analysis of the standard temperature value of the oil-immersed transformer:
1. Winding temperature standard

Allowable temperature:

Oil-immersed transformers generally use class A insulation class, and the allowable temperature of their windings is 105 ° C. This is the temperature at which the oil-immersed transformer is allowed to operate and the temperature that its insulation material can withstand.

Temperature rise standard:

The difference between the temperature of the winding and the ambient air temperature is called the temperature rise of the winding. China’s transformer standards stipulate that the general oil-immersed power transformer winding, relative to the transformer surrounding air temperature rise internal control standard of 65 ° C. This refers to the average temperature rise of the winding, not the hottest temperature rise, and is considered in terms of Class A insulation class (105 ° C). However, in the actual design, for safety reasons, the temperature rise is usually controlled below 65 ° C.

2. Oil temperature standard

Allowable oil temperature:

The oil temperature of an oil-immersed transformer also has its upper limit. In general, the allowable temperature of transformer oil is 105 ° C (it is also said that the oil temperature should not exceed 90 ° C or 85 ° C, which may be related to the specific design and use conditions). In order to prevent the aging of the transformer insulation, the oil temperature at the top of the winding should always be maintained at a level that does not exceed this temperature.

Alarm and trip setting values:

In actual operation, in order to prevent the oil temperature from causing damage to the transformer, the oil temperature alarm and tripping device are usually set. For example, when the oil temperature reaches 80 ° C, an alarm may be triggered; When the oil temperature reaches 95 ° C, the switch of the transformer may automatically jump to cut off the power supply and prevent further accidents.

Third, comprehensive consideration

The standard temperature value of an oil-immersed transformer not only depends on its insulation grade and oil temperature limit, but also is affected by many factors such as ambient temperature, load condition, cooling condition, etc.

In actual use, it is necessary to formulate a reasonable temperature control strategy according to the specific situation of the transformer and the operating environment to ensure that the transformer runs under safe and stable conditions.

At the same time, regular maintenance and inspection of the transformer is also one of the important measures to ensure its normal operation and extend its service life.

To sum up, the temperature standard value of the oil-immersed transformer is a comprehensive indicator, which needs to be determined by considering multiple factors comprehensively. In practical applications, relevant standards and regulations should be strictly observed to ensure the safe operation of transformers.