Products

750kv Power Transformer Bushing

China 750kv Power Transformer Bushing, Find details about China Transformer Bushing, Transformer from 750kv Power Transformer Bushing

Model NO.
750kV power transformer bushing
Size of Bearing Capacity
550KN
Certification
CCC, CE, ISO9001
Color
Red
Brand
Jingcheng
Trademark
Jingcheng
Transport Package
Wooden Box
Specification
10-1100kV
Origin
Hangzhou
HS Code
8546201000
Model NO.
750kV power transformer bushing
Size of Bearing Capacity
550KN
Certification
CCC, CE, ISO9001
Color
Red
Brand
Jingcheng
Trademark
Jingcheng
Transport Package
Wooden Box
Specification
10-1100kV
Origin
Hangzhou
HS Code
8546201000
Transformer bushing
The transformer bushing is the main insulation device outside the transformer box. The outgoing line of the transformer winding must pass through the insulation bushing to insulate the outgoing line and between the outgoing line and the transformer shell, and at the same time, it plays the role of fixing the outgoing line. Due to the different voltage levels, insulating bushing has pure porcelain bushing, oil filled bushing and capacitance bushing. Pure porcelain bushing is mostly used for 10kV and below transformers, it is used to wear a conductive copper rod in the porcelain bushing, and the air insulation is used in the porcelain bushing; oil filled bushing is mostly used for 35kV transformers, it is used to fill oil in the porcelain bushing, and wear a conductive copper rod in the porcelain bushing, and the copper rod is wrapped with insulating paper; capacitive bushing is used for high voltage transformers above 100kV, and the main insulating capacitor core is used for external insulation It is composed of porcelain parts, connecting sleeve, conservator, spring assembly, base, equalizing ball, measuring terminal, wiring terminal, rubber washer, insulating oil, etc.
Transformer bushing is an insulating bushing that leads the high and low voltage leads inside the transformer to the outside of the oil tank. It not only insulates the leads to the ground, but also plays the role of fixing the leads. Transformer bushing is one of the current carrying elements of the transformer. During the operation of the transformer, it passes the load current for a long time, and passes the short-circuit current when the short-circuit occurs outside the transformer. Therefore, the transformer bushing has the following requirements:
(1) It must have the specified electrical strength and sufficient mechanical strength.
(2) It must have good thermal stability and be able to withstand instantaneous overheating in case of short circuit.
(3) Small shape, small quality, good sealing performance, strong versatility and easy maintenance.
structure
The bushing is mainly composed of capacitor core, conservator, flange and upper and lower porcelain bushing. The main insulation is capacitor core, which is made of concentric capacitors in series. It is sealed in a sealed container composed of upper and lower porcelain bushing, conservator, flange and base. The container is filled with treated transformer oil, so that the internal main insulation becomes oil paper structure. The contact surface between the main components of the casing is lined with oil resistant rubber gasket, and each component is under the action of the central pressing force exerted by a group of strong springs in the oil conservator, so that the interior of the casing is in a fully sealed state. The flange is provided with a vent plug, an oil taking device, and a device for measuring the dielectric loss (Tan δ) and partial discharge (PD) of the bushing. During operation, the outer cover of the measuring device must be covered to ensure that the end screen is grounded and no open circuit is allowed.
There are two ways of connection between bushing and transformer high voltage lead: cable threading and current carrying by guide rod.
Inspection items
The inspection items of transformer bushing before installation are as follows:
(1) Whether there are cracks and scars on the surface of porcelain sleeve.
(2) Whether the neck of casing flange and inner wall of equalizing ball are clean.
(3) Whether the casing is qualified after test.
(4) Whether the oil level indication of oil filled casing is normal and whether there is oil leakage.
Operation and maintenance
Casing should be used according to its model under the specified conditions, and the following matters should be paid attention to.
(1) Ensuring casing seal is the key to obtain durable life. The position of the sealing structure moved by the user during installation and maintenance should be carefully restored to the original sealing state.
(2) Oil level control and adjustment. During operation, the change of oil level in casing can be observed regularly. If the oil level is too high or too low, it needs to be adjusted. When the oil level is too high, appropriate amount of oil can be discharged from the flange oil plug; when the oil level is too low, the transformer oil with the same brand and qualified treatment as that marked on the nameplate should be added from the oil filling port of the oil conservator. For the products with normal oil performance in preventive test over the years, the period of preventive test can be appropriately extended to reduce the oil intake. If you have any questions, please contact the manufacturer. It is strictly forbidden to disassemble the casing by yourself.
The correct oil extraction steps are as follows: clean up the dirt at the flange oil plug, open the oil plug, slowly screw in along the central screw hole of the oil plug with a special oil nozzle, hold the plug inside and screw it tightly, and press the sealing ring of the oil nozzle tightly. At this time, the transformer oil in the bushing flows out along the inner hole of the oil nozzle; after the oil is extracted, operate and recover according to the reverse sequence of the above process.
Note: do not loosen the oil plug when screwing off the oil nozzle. If it is found to be loose, tighten the oil plug with 19mm socket wrench on the opposite side in time.
(3) The measuring terminal must be reliably grounded. When measuring the dielectric loss and partial discharge of bushing, screw down the terminal cover and insulate the terminal from the flange. The terminal cover must be covered to ensure reliable grounding. Do not open circuit during operation.
(4) The measured dielectric loss at 10kV may be inconsistent with the factory test data due to the influence of measuring instruments, product location and measuring environment. It is recommended to use the data measured by high voltage Xilin bridge test factory, and the data measured under high voltage shall prevail.

You Might Also Like