What is transformer oil? Transformer oil is used to insulate high-voltage electrical infrastructure such as transformers, capacitors, switches and circuit breakers. Transformer oils are designed to operate effectively at very high temperatures, cooling, insulating, and stopping corona discharges and arcing.
Which oil is used in transformer for cooling?
Naphthenic mineral oil
Naphthenic mineral oil has long been the most preferred insulating liquid for power transformer insulation because it has a good pouring point at low temperatures, good thermal cooling capacity, low cost, high efficiency and availability on the transformers market [1, 2, 3, 7].
What is the purpose of cooling transformer?
Cooling of a transformer is the process of dissipation of heat developed in the transformer to the surroundings. The losses occurring in the transformer are converted into heat which increases the temperature of the windings and the core. In order to dissipate the heat generated cooling should be done.
Why transformer oil is used as a cooling medium?
The transformer oil play two important roles, as a cooling medium transmit the heat generated in coils and core into outer walls to dissipate it and as an electric insulator. According to the available data the heat generated in transformer in full load situation is 1000 W from each coil and 500 W from core.
What are the two major function of transformer oil?
Transformer oil’s primary functions are to insulate and cool a transformer. It must therefore have high dielectric strength, thermal conductivity, and chemical stability, and must keep these properties when held at high temperatures for extended periods.
How do oil filled transformers work?
The transformer windings dissipate waste heat, which needs to be removed. Transformer oil absorbs this heat from the windings and conducts it to the outside of the transformer, where it can be dissipated to the outside air.
What are cooling methods used to cool a transformer?
Transformer Cooling Methods
- Oil Natural Air Natural (ONAN) Cooling.
- Oil Natural Air Forced (ONAF) Cooling.
- Oil Forced Air Forced (OFAF) Cooling.
- Oil Forced Water Forced (OFWF) Cooling.
How does oil circulate in a transformer?
The oil circulates through both the transformer windings and the cooler and the heat lost is transferred either to the ambient air around the transformer or to water. Large transformers use forced oil circulation by electric pumps, aided by external fans or water-cooled heat exchangers.
What is cooling method of transformer?
By Air Natural method the generated heat in the transformer is cooled by the circulation of natural air. When the temperature of the transformer becomes higher as compared to the temperature of the surrounding air, thus by the process of natural convection, heated air is replaced by the cool air.
What properties are required of transformer oil?
The properties (or parameters) of transformer oil are:
- Electrical properties: Specific resistance, dielectric strength, dielectric dissipation factor.
- Chemical properties: Water content, acidity, sludge content.
- Physical properties: Interfacial tension, viscosity, flash point, pour point.
Which type of oil is used for transformer cooling?
KNAN is a transformer that uses less flammable non-mineral oil such as silicone oil, synthetic ester or natural ester (FR3) as the insulating fluid with natural air convection cooling. KNAF has same transformer oil as KNAN but with external forced air cooling.
How does oil work in a transformer?
Transformer oil is a mineral based oil that is commonly used in transformers for its chemical properties and dielectric strength. This oil in your transformer acts as an insulator and a cooling agent. Over time, the oil will degrade resulting in the potential for faults and costly repairs.
What is oil immersed water-cooled transformer?
Oil immersed transformer, also called oil filled transformer, is a kind of voltage transformation device utilizing oil cooling method to reduce the transformer temperature. Different from the dry type transformer, the body of oil immersed transformer is installed in the welded steel oil tank filled with insulation oil.
What is a KVA transformer?
kVA stands for Kilovolt-Ampere and is the rating normally used to rate a transformer. The size of a transformer is determined by the kVA of the load.
