- 2010-11-18 19:46:57
Transformer maintenance and troubleshooting solutions, power transformers in the power plant has a very important role, however, because of its structure, process and operation and maintenance, and many other reasons, failure of power transformers in the power transformer has a very important role, however, Because of its structure, process and operation and maintenance, and many other reasons, the transformer fault in the power plant occurred frequently, greatly affected the plant's normal production. Therefore, to enhance the regular maintenance of the transformer, to take effective measures to prevent transformer failure occur, to ensure safe and stable operation of the transformer has an important significance.
1 Classification of the transformer common symptoms and causes
(1) transformer factory itself, there is the problem. Such as the loose ends, loose pads, bad welding, core poor insulation, lack of resistance to short-circuit strength.
(2) Line interference. Line interference in all the factors that caused the accident in the transformer are the most important. Include: over-voltage generated when the closing, in low load periods, peak voltage, line fault, as well as other aspects of the flashover abnormal phenomena. Such failures in the transformer failures account for a large proportion. Therefore, the impact must be regularly transformer protection test, testing the strength of the transformer inrush current resistance.
(3) The improper use of the transformer insulation aging faster. The average life expectancy is only general transformer 17.8 years, significantly lower than the expected life of 35 to 40 years.
(4) over-voltage caused by lightning.
(5) overload. Overload is the nameplate power transformer work over a long period of state of the transformer. Overload often occurs slowly and continuously improve plant load conditions, the cooling device is not running properly, the transformer internal fault, etc., eventually leading to the transformer overload operation. The resulting high temperature can lead to premature aging of insulation, when the transformer insulation aging cardboard, paper strength decreased. Therefore, the impact of external fault can lead to insulation damage, and then fail.
(6) moisture: If the flood, plumbing leak, roof leaks, water intrusion along the pipe or fittings in the fuel tank and the existence of water and other insulating oil.
(7) did not carry out proper maintenance.
2 Transformer Operation fault analysis and treatment measures
(1) the primary winding insulation and turn insulation failure. The main transformer winding insulation and turn insulation failure of the site is easy. Main reason is: overload due to the long run, or heat conditions are poor, or a long service life, so that the transformer winding insulation aging embrittlement, electric strength greatly reduced; transformer short-circuit many times by the impact of the winding force deformation, hidden insulation defect, once the case of voltage fluctuation is likely to insulation breakdown; transformer oil dielectric strength of water that can not afford to allow greatly reduced voltage, resulting in insulation breakdown; in the high or low voltage winding at the winding section to strengthen parts of the insulation expansion of the oil duct obstruction, affecting the heat, to make the winding insulation aging due to overheating, short circuit breakdown occurs; the mine facilities inadequate, over-voltage effects in the atmosphere, the occurrence of insulation breakdown.
(2) transformer bushing failure. Flashover main casing and explosion, the general use of the transformer high voltage side capacitor casing, the casing and the porcelain cracks bad or have trachoma, casing Mifengbuyan have oil leakage; tube fouling too much and others have and may result in flashover explosion.
(3) core insulation failure. Stacked transformer core formed by the silicon steel, silicon steel sheet between the insulating film. Fastening the silicon is not good, so that eddy current coating damage local overheating occurs. Similarly, the core of the mandrel clamping screws,? R iron and other components, insulation damage can occur if overheated. In addition, if the residual iron in the transformer or welding slag, the iron core ground two or more points will result in core failure.
(4) Tap failure. Transformer transformer tap is one of common faults. As a long time by the pressure switch contact spring pressure appears insufficient to switch connection part of the effective contact area decreases, and the contact part of the silver coating wear off, causing the tap running in the heat damage. Tap is bad, unable to withstand the impact of short-circuit current caused by the tap-burn failure; at OLTC transformer tap transformer tank and the tank is generally mutually unintelligible. If you tap a serious lack of oil tank, then tap the switch in the short-circuit fault occurs, the tap-burn.
(5) gas protection fault. Gas protection is the main transformer protection, the role of the signal light gas, heavy gas acting on the trip. The following causes of action and the gas protection approach: first, the light signal when gas protection. The reason: there are minor faults within the transformer; transformer that exist within the air; secondary circuit failure and so on. Operating personnel should immediately check, if no abnormal phenomenon should be carried out sampling of the gas. Second, the gas protection Tripping may have serious faults within the transformer, causing decomposition of large amounts of gas oil, etc. may also be secondary circuit fault. Gas protection Tripping occurs, should be cast spare change, then the external examination. Check the oil pillow blast doors, the welding seam is split, whether the deformation of the transformer casing; final inspection of the combustible gases.
(6) handling of automatic tripping the transformer. When each side of the transformer circuit breaker automatically trip, the first trip the circuit breaker to trip after the control switch operating position, and quickly put into standby transformer, adjusting the operation mode and load distribution, operating systems and equipment to maintain a normal state. Protection of action and then check the conditions for external inspection. The inspection is not an internal failure but because of the external fault (through failure) or other persons caused by malfunction, you can not get through internal examination can be put into power. In the case of differential, heavy gas, such as the main protection action quick break to address the protection of all equipment within the scope of inspection. Without further investigation before the ban will be put into operation the transformer.
(7) transformer fire is a dangerous accident. The transformer casing damage or flashover, the hydraulic oil in the oil under the action of pillow out and burn in the transformer on the roof; transformer internal fault, the oil burning and to shell rupture. There are many flammable substances because of the transformer, not in time could cause an explosion or the fire to expand. Occurrence of such incidents, the transformer should move off the breaker. If for any reason without disconnecting circuit breaker should immediately disconnect the circuit breaker manually, pull the power transformer may lead to the isolation switch, and quickly put spare change, restore power to stop the operation of cooling equipment, put out the fire. Transformer fire, it is best to use foam or dry powder fire extinguisher fire extinguishers, fire fighting when necessary, the sand can be used.
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Contact Person:Lu Jianxin