Using symmetrical components for fault discrimination in differential protection
BY IMRAN RIZVI, ABB Inc.
Classical differential protection schemes are subject to ghost differential currents due to current transformer (CT) saturation and magnetization currents. Several methods are used to counter the impact of these unwanted differential currents. Electricity Today Magazine and ABB will focus on how to improve transformer protection by using the symmetrical component techniques to stabilize differential protection schemes without sacrificing the speed and...
Insulation Resistance (IR) test, often called Megger test, is more than 100 years old and assumed to be a very straightforward test. During my inspection and testing work in the past 15 years in Canada, US, and internationally, I have seen different practices of performing and interpretation of IR...
In today’s society we are faced with many obstacles, one of these obstacles is the high cost of electricity around the world. Electricity prices for commercial, industrial and institutional have increased a considerable amount. There are many reasons why this is occurring, including the lack...
As a philosophy and English major who has spent the last 20+ years working in the utility industry,I often come across topics that challenge me because I don’t have a science or engineering background. This article is an exploration of the basics around online DGA monitors, to better...
FLIR Systems, Inc. (NASDAQ: FLIR) on September 3, 2019 in Arlingon, Va. announced the FLIR T860, the latest addition to the high-performance T-Series family. This new thermal camera is the first to feature onboard Inspection Route software, ideal for streamlining inspections of critical assets,...
Critical infrastructure security is in the national spotlight. In 2020, the power grid and energy sector was the third most targeted sector for cyber-attacks, up from ninth place in 2019, and the threats are growing more sophisticated. The Biden administration recently issued a national security...
There are two standard methods from ASTM International: D877, Standard Test Method for Dielectric Breakdown Voltage of Insulating Liquids Using Disk Electrodes, and D1816, Standard Test Method for Dielectric Breakdown Voltage of Insulating Oils of Petroleum Origin Using VDE Electrodes. VDE stands...
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By Chris Rutledge, Product Manager, Dynamic Ratings, Inc. Introduction The utilization of online dissolved gas analysis monitoring has proven to be one of the most effective predictors of overall transformer health and condition. A wide range of monitoring systems are available, offering multiple...
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By R. W. Hurst, Editor Grounding transformers are used to provide a path to ground for unbalanced load current and for fault currents on systems where a suitable ground is otherwise not available. Grounding transformers are normally constructed with one of the two configurations: Zig-Zag (Zn) with...
