Jimmy Andrews

The transformer oil degassing process in power transformers involves the removal of dissolved gases, primarily hydrogen and moisture, from the insulating oil. This is typically achieved through a combination of heating and vacuum techniques, which lower the boiling point of the gases, allowing them to escape. Effective degassing enhances the dielectric strength of the transformer oil, reduces the risk of electrical breakdown, and improves the overall reliability and performance of the power transformer.

Paraffinic transformer oil is a type of insulating oil derived from paraffinic crude oil, characterized by its high dielectric strength and low viscosity. In power transformers, paraffinic transformer oil is used as an insulating medium to prevent electrical discharges and to dissipate heat generated during operation. Its chemical stability and resistance to oxidation enhance the longevity and reliability of power transformers, ensuring efficient performance in electrical systems.

The purpose of a transformer oil moisture sensor in power transformers is to monitor the moisture content in the transformer oil. High moisture levels can lead to reduced insulation effectiveness, increased risk of electrical breakdown, and accelerated aging of the oil. By continuously measuring moisture levels, the sensor helps ensure the reliability and longevity of the transformer, allowing for timely maintenance and reducing the risk of failures.

Transformer oil provides electrical insulation between energized components, removes heat from windings and core, suppresses arcing, and protects solid insulation from oxidation. These combined functions enable safe high-voltage operation, compact transformer design, and long operational life in power and distribution systems.

An oil filled current transformer uses oil as both insulation and cooling medium around the core and windings. The CT steps down primary current to a standardized secondary current for metering and protection while providing high voltage insulation to the primary conductor. The oil fills voids, improves dielectric strength, and helps dissipate heat from losses. Many designs include an expansion space, seals, and bushings to maintain insulation integrity. Periodic checks include oil level, leaks, and dielectric condition depending on design and criticality.

MIDEL branded fluids are commonly ester based insulating liquids selected when fire safety and environmental impact matter, such as urban, tunnel, or water proximity sites. Esters typically offer higher fire points and better biodegradability than mineral oil, helping reduce fire propagation risk and environmental remediation burden after a leak. Utilities still verify compatibility, moisture behavior, and aging performance against their standards and asset strategy.

A treatment machine restores oil by removing moisture, gases, and solids using heating, vacuum dehydration, and filtration. It may also include degassing columns and fine particulate filters. Some systems incorporate adsorption media to reduce acidity and polar degradation products. Treatment improves breakdown voltage, reduces dielectric losses, and restores heat transfer performance. After treatment, oil is sampled to confirm acceptance values for BDV, moisture, acidity, and dielectric dissipation factor. Proper hose sealing and dry handling prevent re contamination during transfer back into the transformer.