What is oil-immersed current transformer??
An oil-immersed current transformer is a type of transformer that is used to measure the current flowing in an electrical circuit. The transformer is immersed in oil to insulate and cool the windings. This type of transformer is typically used in high voltage transmission and distribution systems. In this article, we will explore the features, functions, and applications of oil-immersed current transformers.
Features of Oil-Immersed Current Transformer
The core and windings of an oil-immersed current transformer are imbedded in oil. This provides excellent insulation and cooling of the transformer. The insulation properties of the oil are superior to air, and oil-cooled transformers can operate at higher temperatures without degrading the insulation. In addition, the oil has a high heat capacity, which means it can absorb and dissipate large amounts of heat. The tank that holds the oil is made of steel and is hermetically sealed to prevent leakage.
Functions of Oil-Immersed Current Transformer
The primary function of an oil-immersed current transformer is to measure the current flowing in a high voltage electrical circuit. The transformer produces a secondary current proportional to the primary current. This secondary current is then used to measure and protect the electrical system. Oil-immersed current transformers are also used to provide insulation and protection against electrical faults such as short circuits and overloads.
Applications of Oil-Immersed Current Transformer
Oil-immersed current transformers are used in a variety of applications, including power generation, transmission and distribution. They are commonly used in high voltage power systems to measure the current flowing through the system. The transformers can be found in power plants, substations, and electrical transmission lines. In addition, oil-immersed current transformers are used in protective relaying systems to detect faults and protect the equipment.
Advantages of Oil-Immersed Current Transformer
There are several advantages of using oil-immersed current transformers. Firstly, they provide superior insulation compared to air-cooled transformers. Oil has a high dielectric strength, which makes it an effective insulator. Secondly, the oil provides excellent cooling properties for the transformer. This allows the transformer to operate at higher temperatures without degrading the insulation. Thirdly, the hermetically sealed tank prevents moisture from entering the transformer, which can cause shorts and other electrical problems.
Disadvantages of Oil-Immersed Current Transformer
Despite the advantages, there are some disadvantages of oil-immersed current transformers. Firstly, they require regular maintenance to ensure the oil is clean and free of contaminants. The oil can become contaminated with moisture, dirt, and other pollutants, which can reduce the insulation properties and cooling capacity of the transformer. Secondly, the oil can leak from the transformer, which can be a safety hazard and can cause damage to the equipment.
Care and Maintenance of Oil-Immersed Current Transformer
To ensure reliable operation of an oil-immersed current transformer, regular care and maintenance are essential. The transformer should be inspected periodically to ensure the oil level is correct and the tank is free of leaks. The oil should be tested for contamination and replaced if necessary. The transformer should also be protected from moisture and extreme temperatures to prevent damage to the insulation. It is important to follow the manufacturer's recommended maintenance schedule and procedures.
Conclusion
An oil-immersed current transformer is an essential component of high voltage electrical systems. It provides accurate measurement of the current flowing in the system while providing insulation and protection against electrical faults. The transformer requires regular maintenance to ensure its reliability and performance. By understanding the features, functions and applications of oil-immersed current transformers, we can appreciate their importance in the power generation and transmission industry.