The fault of baoding oil-immersed transformer is a very common type, especially the short-circuit phenomenon of baoding oil-immersed transformer accounts for more than 80% of all fault types, most of the faults are related to short-circuit. How many short-circuit faults are there in baoding oil-immersed transformer?
Because baoding oil is immersed transformer outlet short circuit brings about oil to be immersed type transformer interior defect and the reason of incident are very much, more complex also, it and structure depict, the quality of original data, craft level, the factor such as working condition is concerned, but of electromagnetism line choose is crucial. According to the static theory of baoding oil-immersed transformer, the electromagnetic line selected in recent years is different from the stress acting on the electromagnetic line in practical operation.
1. The winding system is relatively loose, with improper transposition disposal and too thin, forming a suspended electromagnetic line. From the perspective of the end damage azimuth, deformation is often seen at the transposition, especially the transposition of the transposed conductor.
2, in the current accounting sequence of each manufacturer is spread evenly on leakage magnetic field, the line circle diameter is same, on the basis of the force of phase such as idealized model and compiled, and the fact of baoding oil-immersed transformer leakage magnetic field is not evenly distributed, the local relative converged on iron yoke, the area of electromagnetic wire by mechanical force is bigger also. When the transposition conductor climbs the slope at the transposition position, it will change the direction of power transmission and cause torque. Due to the factor of the elastic modulus of the pad block, the axial pad block is not evenly distributed, which will make the alternating force delayed resonance caused by alternating leakage magnetic field, which is also the fundamental reason why the line cake in the yoke of the core, transposition, the corresponding part of the pressure regulating tap is the primary deformation of the line cake.
3. Improper control of pretension force of windings leads to dislocation of common transposition wires.
4. The influence of temperature on bending resistance and tensile strength of electromagnetic wires is not considered when calculating the resistance to short circuit. Can the short-circuit resistance described at room temperature not reflect the actual operating conditions, according to the experimental results, the temperature of the electromagnetic line to its limit? 0.2, followed by the temperature of the electromagnetic wire progress, the bending, tensile strength and elongation are falling, bending tensile strength under 250 ℃ than at 50 ℃ whereabouts, elongation is down more than 40%. And practical operation of baoding oil-immersed transformer, under the additional load, the average winding temperature is 105 ℃, the hottest temperatures up to 118 ℃. Ordinary baoding oil-immersed transformer are reclosing when working process, so if you can't see, short-circuit point at that time will be in a very short period of time (0.8 s) and then to accept the second short circuit impact, but due to the short circuit current shock for the first time, after winding temperature increased sharply, the winding anti-short circuit ability drops sharply, which is why oil-immersed transformer short-circuit trouble after reclosing attack in the majority.
Baoding oil immersed transformer short circuit phenomenon is very common, but the occurrence of short circuit phenomenon is not terrible, terrible is the occurrence of short circuit do not know what reason, do not know how to solve is the most terrible, so baoding oil immersed transformer solution process must be carefully to understand!
Baoding zhongyi electric material manufacturing co., ltd. is a professional transformer manufacturer in baoding transformer factory, with professional production equipment, lifting, tooling and testing equipment, established a perfect quality management system, product performance indicators have reached the standard.
The company's main products: baoding dry transformer, baoding box transformer, baoding oil-immersed transformer, baoding high and low voltage complete sets of equipment. I companies to follow "detail decides success or failure, honesty molded the future" of the enterprise purpose, adhere to "quality measuring market, seek development by innovation, to management for efficiency" business philosophy, to make my company's products are widely used in power plant, chemical, construction, mining, metallurgy, rail transportation and other industries, to meet the needs of various users, my company rely on superior product quality, thoughtful service, won the trust of our customers.
