After the impregnated material transformer is wound there is another process， which is to impregnate the insulation paint. It can enhance the mechanical strength， improve the insulation performance， and extend the service life of the transformer. Generally， cresol varnish or insulation paint or resin paint can be used as the impregnating material. In addition to converting AC voltage， special transformers also have various other uses， such as changing the frequency of power sources and rectifying equipment 5When the actual load borne by the transformer during operation is less than ， the small capacity transformer should be replaced. If it is greater than the rated capacity of the transformer， the large transformer should be replaced immediately. At the same time， when selecting a transformer， the voltage value of the primary winding should be determined based on the power supply of the line， and the voltage value of the secondary winding should be selected based on the electrical equipment， preferably using a low-voltage three-phase four wire power supply. This can provide both power and lighting electricity simultaneously. jLiaoningBecause in the event of a transformer short circuit， displacement may occur between the pressure plate and the clamp， causing the grounding connection piece between the pressure plate and the iron yoke on the pressure nail to break or be burned due to overcurrent. Therefore， for the winding pressure plate， it is also necessary to check whether the grounding connection between the winding， pressure nail， which can easily burst and damage the equipment when subjected to rapid cooling or uneven cooling at high temperatures， potentially causing unnecessary losses. If the casing with insulating oil bursts， the insulating oil will spread and the fire will spread further. Therefore it is better to use spray water to extinguish the fire and pay attention to evenly cooling the equipment. RFrancistownIn this way， the insulation medium can be transformer oil or high ignition point oil. After immersion in oil， the dielectric constant of Nomex paper (which is related to the density of Nomex paper) is close to that of oil， and the thermal conductivity of Nomex paper is similar to that of general fiber paper. The onboard transformer for domestic electric locomotives is an insulation system composed of Nomex paper and silicone oil， which has been in operation for many years. It should be possible to extend this insulation system to oil immersed distribution transformers (column mounted， foundation mounted， buried). The International Electrotechnical Commission is considering developing design guidelines for distribution transformers that utilize high temperature resistant insulation materials as insulation systems. FlPower transformer， but not an early transformer. The above three factors determine the service life of the transformer. Practice and research have shown that if the winding can continuously maintain a temperature of ℃， the service life of the transformer can be guaranteed. According to the relationship between temperature and lifespan a so-called ℃ rule can also be derived: based on the lifespan at the above temperature， for every ℃ increase in winding temperature， the service life of the transformer is shortened by half.
The construction and basic principles of transformers: Transformers， also known as inverters， are electrical facilities that convert high-voltage electricity produced by power plants into low-voltage electricity required by electrical appliances during long-distance transmission of electrical energy. They have multiple functions such as transformation and current conversion. According to the function of power transmission and distribution， it can be divided into step-up， step-down， and distribution transformers. According to different cold distribution media， it can also be divided into three types: air self cooling， dry-type， and oil immersed. Among them， oil immersed transformers are a widely used type， mainly composed of a main body， a cooling part， a lead out device， and a protection device. sGenerally， the coil connected to an AC power source is called a primary coil; The voltage across this coil is called the primary voltage. The induced voltage in the secondary coil may be greater or less than the primary voltage， which is determined by the turns ratio between the primary and secondary coils. Therefore， transformers are divided into two types: step-up and step-down transformers. JTransformers have various other uses besides converting AC voltage， such as changing the frequency of power sources， supplying power to rectification equipment， supplying power to electric furnaces， or serving as voltage transformers， current transformers， etc. These transformers with special purposes are commonly referred to as special transformers. Due to the different working conditions and load conditions of these transformers compared to general transformers， they cannot be calculated using the calculations of general transformers. KRecommendation and consultationThe loss of transformer core is closely related to frequency， so it should be designed and used according to the operating frequency， which is called the working frequency. lWSingle phase transformer: used for single-phase loads and three-phase transformer groups. Use high-pressure atomized water flow to extinguish the fire.
The power of the primary and secondary coils of an ideal transformer is equal， P=P. The ideal transformer itself has no power loss. The actual transformer always has losses， and its efficiency is&eta= P/P. The efficiency of power transformers is very high， reaching over %. [] The classification of commonly used transformers can be summarized as follows []: Inspection standardzRefers to the power loss measured at the primary level when the secondary of the transformer is open circuited. The main loss is iron core loss， followed by the loss caused by no-load current on the copper resistance of the primary coil (copper loss) which is very small. SThe nearby kVA distribution transformer is connected on the low voltage side with a tie line， and the load of the two distribution transformers is supplied by one of them， while the other is shut down for backup. According to the formula， I&prime= A. Indicate the insulation performance between each coil of the transformer and between each coil and the iron core. The level of insulation resistance is related to the performance of the insulation material used， the temperature， and the degree of humidity Transformer is a static electrical device used to convert a certain value of AC voltage (current) into another or several different values of voltage (current) with the same frequency. Transformer is a static electrical device used to transform AC voltage and current and transmit AC energy. It is based on the principle of electromagnetic induction to achieve the transmission of electrical energy. Transformers can be divided into power transformers， test transformers， instrument transformers， and special-purpose transformers based on their uses: power transformers are necessary equipment for power transmission and distribution， as well as power distribution for power users; Equipment for conducting voltage withstand (boost) tests on electrical equipment using test transformers; Instrument transformers are used for electrical measurement and relay protection in power distribution systems (PT， CT); Special purpose transformers include smelting electric furnace transformers， welding transformers， electrolytic rectifier transformers， small voltage regulating transformers， etc. [] uLiaoningThe casing experiences corona and flashover discharge due to contamination. Flashover discharge of casing can cause heating， aging， insulation damage and even explosions， and can also produce ozone odor. lREasy installation and demolition， with a small footprint， can be installed indoors or outdoors. Oil immersed transformer: relying on oil as the cooling medium， oil immersed self cooling， oil immersed air cooling， oil circulation， etc.
