Most popular Xuzhou underground power transformer

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Xuzhou underground power transformer quotation

abnormal operation and emergency treatment of transformer (3)

the action of gas relay generally has two kinds according to the nature of fault: one is signal action without tripping; One is to act both at the same time

if the signal acts without tripping, Xuzhou underground power transformer quotation_ [Pengcheng electric] usually has the following reasons

① air enters the transformer due to oil leakage, oil filling or lax cooling system

② the oil level drops slowly due to temperature drop or oil leakage

③ a small amount of gas is generated due to transformer failure

④ caused by through short circuit

if the signal acts at the same time with the switch, or only the switch acts, Xuzhou underground power transformer quotation_ [Pengcheng electric] may be due to serious internal fault of the transformer, too fast oil level drop or failure of the secondary circuit of the protection device. In some cases, such as after repair, Xuzhou underground power transformer quotation_ [Pengcheng electric], the air in the oil separates too fast, which may also trip the switch

(d) transformer oil leakage treatment

oil leakage includes weld oil leakage and seal oil leakage. The treatment of weld oil leakage is repair welding. During welding, lift out the body and drain the oil. The cause of sealing oil leakage should be found out, such as poor operation (the sealing gasket is not placed correctly, the pressure is uneven, the pressure is not enough, etc.), and it should be repaired as appropriate. If the gasket is aged or damaged (such as oil resistant rubber sticking, losing elasticity, cracking, etc.), the sealing material should be replaced

patrol inspection of oil immersed transformers

patrol inspection and monitoring should be carried out frequently for transformers in operation, so as to find abnormal phenomena or faults in time. Heilongjiang, a resource rich province, avoids serious accidents in the process of helping enterprises reduce production capacity

items that should be checked and monitored generally include:

the integration degree of components and parts has been greatly improved (1) whether the transformer has abnormal sound, such as uneven sound or discharge sound

(2) whether the oil level is normal, and whether there is leakage and oil leakage

(3) whether the oil temperature is normal (the upper oil temperature generally shall not exceed 85 ℃)

(4) whether the casing is clean and whether there are cracks, damages, discharges and other phenomena

(5) whether the joint is heated

(6) whether the explosion-proof membrane of the explosion-proof pipe is complete

(7) whether the gas relay leaks oil and whether the interior is full of oil

(8) whether the respirator is unblocked, whether the oil level of the oil seal respirator is normal, and whether the silicone in the respirator is saturated with moisture

(9) whether the cooling system operates normally

(10) whether the grounding wire of the shell is intact

performance characteristics of oil immersed transformer

a. the low-voltage winding of oil immersed transformer generally adopts the cylindrical structure of copper foil winding except for the small capacity copper conductor; The high-voltage winding adopts multi-layer cylindrical structure, so that the ampere turn distribution of the winding is balanced, the magnetic leakage is small, the mechanical strength is high, and the short-circuit resistance is strong

b, the iron core and winding adopt fastening measures respectively. The fastening parts such as the height of the device and the low-voltage lead are equipped with self-locking locknuts, and the non hanging core structure is adopted, which can withstand the bumping of transportation

c, the coil and iron core are vacuum dried, and the transformer oil is vacuum filtered and injected to minimize the moisture inside the transformer

d. The oil tank adopts corrugated sheet, which has breathing function to compensate for the volume change of oil caused by temperature change. Therefore, this product has no oil conservator, which obviously reduces the height of the transformer

e. since the corrugated sheet replaces the oil conservator, the transformer oil is isolated from the outside, which effectively prevents the entry of oxygen and water, resulting in the decline of insulation performance

f. According to the above five performances, the normal operation of the oil immersed transformer is guaranteed. Scientists believe that almost every piece of plastic produced exists in a certain place in a certain situation, and there is no need to change the oil, which greatly reduces the maintenance cost of the transformer and prolongs the service life of the transformer

phase number differentiation

can be divided into three-phase transformer and single-phase transformer. In the three-phase power system, three-phase transformers are generally used. When the capacity is too large and limited by transportation conditions, three single-phase transformers can also be used to form a transformer group in the three-phase power system

winding differentiation

can be divided into double winding transformer and three winding transformer. Usually, the transformer is a double winding transformer, that is, there are two windings on the iron core, one is the primary winding and the other is the secondary winding

the three winding transformer is a transformer with large capacity (above 5600 kVA), which is used to connect three different voltage transmission lines. In special cases, there are also satons transformers with more windings

structural classification

can be divided into iron core transformer and iron shell transformer. If the winding is wrapped around the core, it is an iron core transformer; If the iron core is wrapped around the periphery of the winding, it is an iron shell transformer

the two are slightly different in structure, and there is no essential difference in principle. Power transformers are of iron core type

the transformer is mainly composed of iron core, winding, oil tank, conservator, insulating sleeve, tap changer and gas relay

advantages and disadvantages of dry-type and oil immersed transformers

in terms of cost, dry-type transformers are more expensive than oil immersed transformers. The capacity of oil immersed transformer is larger than that of dry-type transformer. Dry type transformers are required in underground floors, floors and crowded places. Oil immersed transformers are used in independent substations. Box type substation generally uses dry-type transformer. When the space is large, the oil immersed transformer is used, and when the space is crowded, the oil immersed transformer is used. When the regional climate is humid, use oil immersed transformer. Dry type transformers are used in places that need "fire and explosion prevention". The capacity of dry-type transformer to bear load is worse than that of oil immersed transformer. Dry type transformers shall operate at rated capacity. The oil immersed transformer allows short-term overload

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