Why does dry type transformers get fire
The safety and operation of dry-type transformers is an important operation mode of dry-type transformers and it directly determines the operation effect of dry-type transformers. Dry transformer fires often occur during the main operation of dry transformers. In fact, fires often occur in dry-type transformers. The main reason is the short-circuit and aging of dry-type transformer lines.
In general speaking, the temperature of a certain part of the dry-type transformer has risen, reaching the ignition point of the dry-type transformer oil, igniting the dry-type transformer oil, and burning it. During normal operation of the dry-type transformer, the temperature will not rise to the ignition point. It is only possible to rise to the ignition point in the event of a fault. Such failures are generally caused by increased current or (and) increased resistance. There are generally two reasons for the increase in current.One is severe overload (including external short circuit). The other is that the dry transformer itself has insulation damage and an internal short circuit occurs. If the internal short circuit is severe, the dry type transformer will explode. Dry-type transformers have a variety of perfect protection measures when they work. If an increased current fault occurs, the protection measures will generally act, thereby protecting the safety of the dry-type transformer. Therefore, the fire failure of dry-type transformers is relatively rare in practice. The reason for the increased resistance is poor contact and high temperatures can also occur in poor contact areas, causing fire. For this kind of failure, general protection measures are difficult to obtain.
Most of the causes of dry-type transformer fire are caused by insulation aging. The dry-type transformer in operation must withstand the heat generated by the applied electric field and no-load loss, load loss, etc. In addition, the environment (temperature in the air) affects the insulation. Insulation materials under the influence of electric field strength, heat and other factors cause insulation aging, and gradually lead to insulation breakdown and insulation loss of electrical performance.
1. Initial breakdown: May be a manufacturing error, caused by a weak point in the insulation
2. Sudden breakdown: This is due to the nature of the product
3.Aging breakdown: long-term operation, the result of insulation aging.