Characteristics Of Dry-type Transformers

Compared to oil-filled transformers,dry transformer have no oil, thus eliminating problems such as fire, explosion, and pollution. Therefore, electrical codes and regulations do not require dry type transformer manufacturers to be placed in a separate room. In particular, the new series has reduced losses and noise to a new level, creating conditions for placing the transformer and low-voltage switchgear in the same distribution room.

(1) 750 kva dry type transformer temperature control system. The safe operation and service life of 75 kva dry type transformer largely depend on the safety and reliability of the transformer winding insulation. Winding temperature exceeding the insulation's withstand temperature causes insulation damage, which is one of the main reasons why transformers fail to operate normally. Therefore, monitoring and alarm control of the transformer's operating temperature are extremely important.

(2) dry type distribution transformer protection methods. Depending on the characteristics of the operating environment and protection requirements, dry cell transformer can be equipped with different enclosures. Typically, an IP23 protective enclosure is used, which prevents solid foreign objects larger than 12mm in diameter and small animals such as rats, snakes, cats, and birds from entering, preventing short circuits and other serious faults, and providing a safety barrier for live parts. If the transformer needs to be installed outdoors, an IP23 protective enclosure can be used. In addition to the IP20 protection functions mentioned above, it also prevents water droplets from entering at an angle of less than 60° to the vertical. However, the IP23 enclosure will reduce the transformer's cooling capacity, so attention should be paid to the reduction in operating capacity when selecting it.

(3) 1000 kva dry type transformer cooling methods. 2500 kva dry type transformer cooling methods are divided into natural air cooling (AN) and forced air cooling (AF). With natural air cooling, the transformer can operate continuously at its rated capacity for a long time. With forced air cooling, the transformer's output capacity can be increased by 50%. This is suitable for intermittent overload operation or emergency overload operation; however, because the load loss and impedance voltage increase significantly during overload, resulting in uneconomical operation, it should not be subjected to continuous overload operation for extended periods. (4) Overload capacity of 150kva dry type transformer. The overload capacity of dry-type transformers is related to ambient temperature, load conditions before overload (starting load), insulation and heat dissipation of the transformer, and the thermal time constant. If needed, the overload curve of the dry-type transformer can be obtained from the manufacturer. Currently, the annual production of resin-insulated dry-type transformers in my country has reached 10,000 MVA, making it one of the largest producers and consumers of dry-type transformers in the world. With the widespread application of the low-noise (noise of distribution transformers below 2500 kVA has been controlled within 50 dB) and energy-saving (no-load loss reduced by 25%) SC(B)9 series, the performance indicators and manufacturing technology of dry-type transformers in my country have reached the world's advanced level.