Przemysław

Filtration removes moisture, gases, and particles accumulated during operation. This restores dielectric strength, improves cooling, and prevents insulation degradation, ensuring continued safe and reliable transformer performance.

Topics include gas generation mechanisms, fault interpretation, key gas ratios, IEEE and IEC limits, case studies, trending analysis, and maintenance decision-making based on DGA results.

A mobile transformer oil purifier is used on-site during maintenance, commissioning, or emergency recovery. It treats oil without draining the transformer or transporting oil offsite, making it ideal for substations, remote locations, and large power transformers.

BDV testing indicates the oil’s ability to withstand electric stress without forming a conductive path. Moisture, particles, and oxidation products can sharply reduce BDV, increasing risk of partial discharge, internal arcing, and insulation breakdown under switching or lightning impulses. While BDV alone does not diagnose fault type, it is a fast indicator of contamination and handling quality. It is especially important after oil filling, filtration, or repairs, because poor cleanliness or water ingress can create immediate reliability risk in high voltage assets.

Transformer oil is designed to operate far below its boiling point, but boiling point still matters as a safety margin indicator under abnormal thermal stress. If localized hot spots approach temperatures where lighter fractions volatilize, gas bubbles can form and reduce dielectric strength, increasing partial discharge risk. A higher effective boiling range also supports stable cooling performance, reduces vapor formation in faults, and improves reliability of pressure and gas based monitoring in sealed or conservator systems.

Oil cleaning removes water, gases, and particles that degrade dielectric strength and cooling performance. Moisture lowers BDV and accelerates paper aging, while particles can create local electric stress and trigger partial discharge. Dissolved gases and oxidation byproducts can indicate active faults or ongoing chemical degradation. Cleaning, typically via dehydration and fine filtration, restores BDV and reduces the risk of insulation failure. In many cases it is a cost effective way to extend service life without oil replacement, especially if the base oil is still chemically stable and acidity remains within acceptable limits.

A testing machine may perform breakdown voltage measurement, moisture analysis, dielectric dissipation factor or power factor, resistivity, and sometimes basic acidity screening depending on the instrument. Dedicated laboratory systems also perform dissolved gas analysis and furan analysis. Field kits focus on rapid screening to decide whether filtration, regeneration, or laboratory testing is required. The function is to quantify oil condition, detect contamination, and support maintenance decisions before defects progress to insulation failure. Proper calibration, clean sample handling, and adherence to test standards are essential for meaningful results.

Transformer oil leakage is detected through routine visual inspections, oil level monitoring, and condition indicators. Technicians look for wet spots on tanks, radiators, gaskets, bushings, and valves, as well as oil stains on foundations or containment pits. Oil level gauges and conservator indicators help identify gradual losses. Infrared thermography may reveal cooling inefficiencies caused by low oil levels. Sudden pressure relay alarms or Buchholz relay activation can also signal internal oil loss. Early detection is critical to prevent insulation exposure and moisture ingress.