DGA-Assessment of measuring accuracy. As all of us know the DGA test for transformer oil, is an important test for the assessment of the transformer health. There are a lot of papers and methods guiding to do the thing in the right way. Rogers Ratio method, Duval Triangle Method, Key Gas Method are some of the leading names. However, the aim of today's article is not about discussing these methods but here I will put some fundamentals which will be useful for understanding the basics only.
Busbar Protection and CT Knee Point Voltage Whenever there is mal-operation or non-operation of busbar protection there is debate about CT saturation and CT knee point voltage. In this article, we check this fact mathematically and will also check the importance of busbar stabilizing resistance. It is true that nowadays most of the busbar protection schemes are replaced by numerical one; where stabilizing resistance is not required. However, the REF circuit is also just like the bus-bar protection circuit where still stabilizing resistance is required. This discussion is equally applicable to REF protection too
The Role of Zero Sequence Current Have you wondered ever that in spite of the simple Yyn connection of transformer; why it is necessary to provide zero-sequence filtration for differential protection or for radial feeders; why receiving end line CB trips on distance protection? The cause of such things is the formation of zero sequence currents during faults. How they are formed, the detailed calculations were done by one of our members Er. J. R. Kulkarni. In addition to great insight into the power system, it is a very tedious and time-consuming job. Letus go through the excel sheet to maintain this enthusiasm