Insulating oil is mainly used in the power industry, such as transformers, circuit breakers, oil-filled cables, transformers, power capacitors and bushings and other high-voltage power equipment. According to the different application equipment, it can be divided into transformer oil, capacitor oil, switch oil , cable oil, etc. The main functions of insulating oil are: 1. Insulation; 2. Cooling; 3. Arc extinguishing.
Insulating oil breakdown voltage:
Definition: Under the specified test conditions, the voltage at which the insulating oil breaks down is called the breakdown voltage. The value obtained by dividing the breakdown voltage by the distance between the two electrodes to which the voltage is applied is called the dielectric strength, also known as insulation strength.
1. There will always be some initial free electrons in pure transformer oil;
2. These electrons move under the action of the electric field, resulting in impact ionization and breakdown;
3. The density of liquid is greater than that of gaseous medium, in which the free path of these electrons is very short, and it is not easy to accumulate enough electric energy to produce the required impact ionization.
Why measure the breakdown voltage of insulating oil?
Breakdown voltage energy of insulating oil
(a) It reflects the condition that the insulating oil is dirty, damp, aging, etc., which reduces the insulation level.
(b) a measure of its ability to withstand voltage inside electrical equipment without being damaged
(c) It is one of the main means to test the performance of transformer oil
The reason why insulating oil is always not very pure is:
1. Even in the process of injecting electrical equipment with extremely pure insulating oil, it is inevitable that impurities will be mixed;
2. When the insulating oil is in contact with the atmosphere, it will absorb gas and moisture from the atmosphere, and will be gradually oxidized;
3. Various fibers, debris, etc. fall off the solid insulating material into the liquid medium.
4. During the operation of the equipment, the insulating oil itself will also age and decompose gas, moisture, polymers, etc.
The more fibers shed from the solid insulation, the easier it is for impurity bridges to form, and the lower the breakdown voltage. (Impurity bridge: A local strong electric field is caused near the impurities. Under the action of the electric field force, these impurities will gradually arrange into impurity bridges along the electric force line.)
Therefore, it is necessary to regularly filter the insulating oil with a vacuum Transformer Oil Filter machine to filter out impurities such as moisture, gas, fiber, and debris in the insulating oil, thereby slowing down the oxidation and aging of the oil, and ensuring the excellent performance of insulation, cooling and arc extinguishing.
PureTech manufactures and supplys double stage vacuum Transformer Oil Purification machine, single stage vacuum Transformer Oil Filtration Machine, ultra high voltage transformer oil filter machine, etc. which can meet various demands of power industry. Welcome to contact us for more details.
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