Emilio

The breakdown voltage of transformer oil is a critical parameter that indicates the oil’s insulating strength. Typically, the breakdown voltage of transformer oil should be above 30 kV for effective performance in power transformers. This value can vary based on the oil’s purity, moisture content, and presence of contaminants. Regular testing of the breakdown voltage is essential to ensure the reliability and safety of power transformers in operation.

The transformer oil price in Bangladesh can vary based on market conditions, supplier, and quality. As of the latest data, the price typically ranges from BDT 100 to BDT 150 per liter. Factors influencing the transformer oil price in Bangladesh include import costs, demand for power transformers, and fluctuations in crude oil prices. Regular monitoring of the market is essential for accurate pricing.

The procedure for filling oil in a transformer tank involves several key steps. First, ensure the transformer is de-energized and properly grounded. Next, connect the oil filling apparatus to the designated filling port. Carefully monitor the oil level during the filling process to avoid overfilling. It is crucial to filter the oil to remove impurities before filling. Finally, check for leaks and ensure all connections are secure after the filling is complete.

The usage of oil in a transformer is primarily for insulation and cooling. Transformer oil provides electrical insulation between live components and helps dissipate heat generated during operation. This oil circulates within the transformer, absorbing heat and transferring it to the radiator or cooling system, thereby maintaining optimal operating temperatures and ensuring the reliability and efficiency of the power transformer.

Paraffinic oils have higher wax content, higher pour points, and better oxidation stability, while naphthenic oils have naturally low pour points and better low-temperature fluidity. Naphthenic oils are widely used in transformers because they flow well in cold conditions without dewaxing. Paraffinic oils may require additives or processing to achieve similar low-temperature performance.

The BDV test is performed by placing an oil sample between two standardized electrodes and gradually increasing voltage until electrical breakdown occurs. The breakdown voltage indicates oil dielectric strength. Multiple tests are averaged to assess oil condition, with low values indicating moisture, contamination, or aging.

Gas analysis, typically DGA, detects dissolved gases produced by overheating, partial discharge, and arcing. Different fault types generate characteristic gas patterns. For example, hydrogen can indicate partial discharge, acetylene strongly points to arcing, and ethylene or methane suggests thermal faults at different temperatures. By trending gas levels and their growth rates, engineers can identify early fault development before it becomes catastrophic. Interpretation uses ratio methods and limits, but the most reliable approach combines DGA trends with operating history, load, temperature, and any electrical test results.

A typical procedure aims to keep oil dry and avoid introducing air. Common steps include draining or isolating old oil as required, evacuating the tank under vacuum, filtering and degassing new or processed oil, and filling under vacuum or with a sealed system to prevent moisture pickup. During filling, technicians monitor oil level, temperature, and leak points, then allow settling and de aeration. After filling, they sample oil for BDV, moisture, and sometimes DGA baseline, verify conservator and breather operation if present, and confirm protection devices and gauges function correctly.