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.
Breakdown process:
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.
Name: PURETECH
Mobile:+86 17815389416
Tel:+86 17815389416
Whatsapp:+8617815389416
Email:sales@cqpuretech.com
Add:1 Xinmao Road, Beibei district, Chongqing, China