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Learn about power transformers — construction, working, testing, protection, and maintenance for efficient voltage transformation in power systems.
In this article, we are going to discuss the theory behind a condenser bushing. We have mainly focused on how the capacitor grading improves the voltage distribution along the thickness of the insulation. We also call it a capacitor graded bushing. There are mainly two types of condenser bushings. These are the OIP bushing and … Read more
We also refer to a resin-bonded paper bushing or a synthetic resin-bonded paper bushing, respectively, as SRBP or RBP bushings, in short form. Before entering the actual discussion of resin-bonded paper bushings, let us understand the meaning of resin-bonded paper. What is the meaning of resin-bonded? We all know that paper is a cellulose material, … Read more
An OIP bushing uses concentric cylindrical capacitors in series between the central conductor and outer insulator housing of the bushing. An OIP bushing serves the same purpose as the other types of bushings do. That means it provides proper insulation between the live conductor and the grounded metallic tank of electrical equipment, such as power … Read more
RIP bushing is a kind of condenser bushing or capacitor-graded bushing. The full form of RIP bushing is Resin Impregnated Paper Bushing. The working principle of an RIP bushing is similar to that of an OIP bushing, and construction-wise, they are almost similar. The only difference is that in an OIP bushing, we use oil … Read more
What is a Transformer Breather? A transformer breather (silica gel breather) is a simple device that keeps moisture out of the transformer. We fit it to the pipe coming out from the transformer conservator tank. When the transformer heats up, the oil expands. When it cools down, the oil contracts. This creates a breathing action. … Read more
The Buchholz Relay is a gas-actuated protection relay. It is a mechanical relay. All oil-immersed transformers that have a conservator tank should be equipped with a Buchholz relay. A Buchholz relay can detect both slow-developing faults and major transient faults occurring within the transformer. It provides an early warning (alarm) for slow-developing faults and initiates … Read more
An Oil Surge Relay, or OSR, is a type of mechanical relay. It operates in response to a sudden oil surge. Need for Separate Diverter Tank Every modern power transformer includes an On-Load Tap Changer (OLTC). During tap-changing operations, some arcing always occurs at the diverter switch contacts. It is desirable to change tap positions … Read more
Transformer oil is a special type of refined petroleum oil. It provides both insulation and cooling to electrical equipment. Additionally, we utilize insulating oil in power transformers and distribution transformers. We fill the gaps between the core, windings, and interior of the transformer tank with this oil. The presence of oil in the gaps enhances … Read more
Transformer oil plays two major roles inside a transformer. It strengthens the electrical insulation between live parts and between live and dead parts inside the transformer tank. It also removes heat from the core and windings by carrying the heat to the radiators. To perform efficiently, transformer oil must possess several important properties. Each of … Read more
Breakdown Voltage (BDV) of Transformer Oil Breakdown Voltage (BDV) indicates the voltage above which an oil electrically breaks down. According to IS 335, new unfiltered transformer oil should have a breakdown voltage above 30 kV (rms) when tested with a 2.5 mm gap. For filtered new transformer oil, it is greater than 60 kV (rms) … Read more