Views: 0 Author: Site Editor Publish Time: 2024-12-30 Origin: Site
Transformer insulation oil is mainly used in all kinds of equipment in the process of power transmission - such as transformers, transformers, switchgear, rectifiers, cables and capacitors in the role of electrical insulation of the liquid insulation medium and the role of heat dissipation of the fluid heat transfer medium.
Transformer oil is a liquid medium specifically used to insulate and cool transformers. It has excellent insulation, thermal stability, oxidation stability and electrical properties, can withstand the role of high voltage electric field for a long time, and effectively prevent the internal components of the transformer from arc, discharge and explosion and other failures to ensure the normal operation of the transformer. With the development and utilization of China's electric power resources, transformer as a key equipment for power transmission, the installed amount is also increasing, and the demand for transformer oil is also rising year by year.
Transformer oil according to the source of base oil, can be divided into mineral oil transformer oil, vegetable oil transformer oil, silicone oil transformer oil and synthetic ester transformer oil four categories.
Mineral oil transformer oil, with its excellent electrical performance and excellent thermal performance, has been used in the field of oil-immersed transformers for nearly 100 years. After a long time of testing, it still steadily occupies the throne of the ideal transformer oil for ultra-high voltage and UHV power transformers, and is an indispensable key factor to ensure the safe and stable operation of such large power equipment. In UHV and UHV transmission scenarios, its excellent electrical performance can provide solid insulation guarantee for reliable transmission of power and effectively resist the risk of current leakage; The excellent thermal performance is like a precise temperature control engine, which timely dissipates the large amount of heat generated during the operation of the transformer and ensures that the internal temperature of the equipment is in a reasonable range.
Vegetable oil transformer oil originated from natural oil crops, is a new type of transformer oil prepared after rigorous pressing process, fine refining process and targeted modification treatment. It has many significant advantages: first, the ignition point is higher, compared with the traditional mineral oil transformer oil, in the face of high temperature or electrical failure caused by the potential fire source, has a stronger fire resistance, greatly improving the safety of power equipment operation; Second, the electrical performance is good, can provide a reliable insulation barrier for the live parts inside the transformer, and effectively reduce the probability of electrical accidents such as short circuit; Third, the source of raw materials is very broad, thanks to nature's rich oil crop resources, such as soybean, rapeseed, etc. can be used as raw materials, which not only ensures a stable supply, but also makes it with renewable characteristics, which is highly consistent with the current concept of sustainable development; Fourth, it has the ability of biodegradation, even if it is accidentally leaked into the environment after use, it can be gradually decomposed under natural conditions, and will not cause long-term and difficult to repair pollution to the ecological environment such as soil and water, and contribute to the cause of environmental protection.
In addition to excellent electrical insulation properties, silicone oil transformer oil also has the advantages of high ignition point, low pour point, small viscosity change with temperature, etc., which is usually used to replace traditional transformer oil in small-capacity transformers below 35KV. However, silicone oil transformer oil is sensitive to partial discharge or breakdown decomposition, the stability of resistance to electrical spark is low, and the insulation stability is reduced under repeated electric shock, so silicone oil transformer oil is generally used for transformers with a capacity below 35KV, and the operating temperature should not be too high.
Synthetic ester transformer oil is mainly made of polyol ester base oil, the most prominent feature is that it has good biodegradability, can be degraded into carbon dioxide and water by active microorganisms (bacteria) in a short period of time, no harm to the environment, especially suitable for occasions with high environmental protection requirements, such as offshore wind farms. Synthetic ester transformer oil has comprehensive performance, in addition to good biodegradability, but also has good fire safety performance, electrical insulation performance, oxidation resistance and aging resistance, while the synthetic ester transformer oil has strong polarity, has a strong affinity for water molecules, even in the case of high water content, it still maintains a high breakdown voltage. The moisture resistance is stronger than mineral oil transformer oil and silicone oil transformer oil.
The main function of transformer oil is to act as an electrical insulating medium to prevent the current from flowing in the part that should not flow, thus ensuring the normal operation of electrical equipment. It is filled in the insulating structure of the transformer and other equipment, effectively isolating the conductive part of different potentials, preventing the direct passage of current, and greatly improving the safety and reliability of the equipment.
The transformer will generate a lot of heat during operation, if the heat can not be dissipated in time, it may lead to overheating or even damage to the equipment. Transformer oil has a good heat dissipation effect, in operation, close to the winding and iron core part of the transformer oil after heating, the temperature rises, volume expansion, due to its specific gravity decreases and rises, after cooling by the cooling device, and then into the bottom of the transformer tank, thus forming a cycle of oil. The oil circulation cools the winding and core and improves the operating conditions of the transformer.
Transformer oil also contains some anti-oxidation and anti-corrosion additives, which can effectively prevent the metal parts inside the equipment from being corroded and oxidized, further extending the service life of the equipment. In addition, the insulating oil is usually isolated from the air to protect the body material from moisture.
