The overload capacity evaluation of the Dry type transformer is a relatively complex but crucial process, which requires comprehensive consideration of multiple factors.
First, the overload capacity of the transformer is closely related to its design parameters. Including the core material, winding material and specifications, and the heat resistance of the insulation material. High-quality core materials and windings of appropriate specifications can improve the transformer's ability to withstand overload to a certain extent. For example, the use of high-permeability core materials can reduce the hysteresis loss and eddy current loss of the core, so that the transformer generates relatively less heat when overloaded.
Secondly, heat dissipation conditions are also a key factor in evaluating overload capacity. A good heat dissipation system can effectively dissipate the heat generated by the transformer during operation, reduce the temperature inside the transformer, and thus improve its overload capacity. The heat dissipation effects of air-cooled and self-cooled Dry type transformers are different, and air-cooled can provide stronger heat dissipation when overloaded.
Furthermore, the load characteristics of the transformer will also affect the evaluation of overload capacity. If the load is stable and continuous, the overload capacity of the transformer is relatively low; if the load is intermittent and fluctuating, the transformer can withstand higher overloads in a short time.
In actual evaluation, the technical specifications of the transformer and the overload curves provided by the manufacturer are usually referenced. These curves show the proportion of load that the transformer can withstand in excess of the rated capacity at different time intervals. For example, some Dry type transformers may be able to withstand 120% of the rated load for a short period of time (such as 1 hour), but only 110% of the rated load for a longer period of time (such as 24 hours).
In addition, the ambient temperature needs to be considered. High temperature environments reduce the heat dissipation effect of the transformer, thereby weakening its overload capacity. Therefore, the overload capacity of Dry type transformers operating in high temperature environments should be reduced accordingly.
In order to accurately evaluate the overload capacity of the Dry type transformer, actual load tests can also be performed. By monitoring the temperature, voltage, current and other parameters of the transformer under different load conditions, it is possible to determine whether it can operate stably and determine its actual overload capacity upper limit.
It should also be noted that although the Dry type transformer has a certain overload capacity, excessively frequent or long-term overload operation will accelerate the aging of the transformer, shorten its service life, and may even cause failures. Therefore, in practical applications, the load should be planned reasonably to avoid unnecessary overload operation as much as possible.
In short, evaluating the overload capacity of the Dry type transformer requires comprehensive consideration of multiple factors such as design parameters, heat dissipation conditions, load characteristics, ambient temperature, etc., and referring to the technical information provided by the manufacturer and conducting necessary tests to ensure that the transformer performs at its best under the premise of safety and reliability.
