Partial discharge mainly refers to the internal insulation discharge of baoding dry-type transformer, mutual inductor and other high-voltage electrical equipment under the action of high voltage. This kind of discharge only exists in the insulation local position, will not immediately form the entire insulation penetration breakdown or flashover, so called partial discharge. The local discharge is very weak and cannot be detected by people's intuition, such as eyes, ears and hearing. Only highly sensitive partial discharge measuring instruments can detect it.
Baoding internal insulation dry type transformer under the action of long-term operation in the working voltage, especially with the increase of voltage grade, insulation on the electric field intensity value is very high, it is easy to generate partial discharge in insulation weak place, causes of partial discharge are: electric field is too focused on a certain point, or some point electric field intensity is too large, such as solid medium have bubbles, impurities not shaved; The oil contains water, gas and suspended particles; In different media combinations, there are serious electric field distortion at the interface. Marks of partial discharge often leave only a small spot, or dendritic burn, on solid insulation. In oil, small bubbles break down.
Partial discharge time is short, energy is very small, has a great harm, but its long-standing will produce greater damage to insulation materials, one is the insulation material to adjacent partial discharge, discharge by particle bombardment directly cause local damage of the insulation, the second is the heat generated by the discharge, ozone, the chemistry of the reactive gas such as nitrogen oxide, make local insulation aging from corrosion, conductivity increases, eventually leading to thermal breakdown. Baoding dry transformer in operation, internal insulation aging and damage, mostly from partial discharge.
Transformer partial discharge detection methods generally include:
1. Electric measurement. Use oscillograph or radio interferometer to find the characteristic waveform or radio interference degree of discharge.
2. Ultrasonic measurement. The sound wave appearing in the discharge is detected, and the sound wave is transformed into electrical signal, which is recorded on magnetic tape for analysis. By using the difference of transmission time between the electrical signal and acoustic signal, the distance from the detection point to the discharge point can be obtained.
3. Chemical measurement. The content, increase and decrease of dissolved gas in oil were detected. The method can detect changes in the composition, proportion and quantity of the oil to determine whether there is partial discharge (or local overheating).
In addition, in recent years, an on-line partial discharge detector has been developed, which can automatically detect partial discharge in transformer operation.
In order to prevent partial discharge, the manufacturer should design the structure of baoding dry-type transformer reasonably. Careful construction, improve the purity of materials, strictly handle the quality of each link. The operation unit should strengthen the maintenance and monitoring of baoding dry-type transformer so as to effectively prevent the partial discharge of baoding dry-type transformer.
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.
