Power transformers seldom shutdown; however, if a shutdown occurs, the effects would be immediate and devastating to utility operations. According to “An Analysis of Transformer Failures” by William H. Bartley, P.E., on behalf of the Hartford Steam Boiler Inspection and Insurance Company, the average age at the time of failure ranged from only 9.4 to 14.9 years. This revelation is enough to prompt utilities to take a second look at their policies and practices...
Introduction Fault type identification is an important step in dissolved gas analysis (DGA). When a significant amount fault gas production is detected in a transformer, we want to know what kind of physical condition could be responsible for the gassing. Knowing the type of fault can help to...
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...
ABSTRACTHere we discuss the phenomenon of transformer inrush; what it is and its significance to transformer protection design. INTRODUCTIONA couple of years ago in this Transformer Special Edition, we wrote an article that covered the most used transformer protection schemes. As was pointed out...
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. Monitoring can vary greatly from nine gas to single gas systems to best suit the customers application when considering...
IntroductionContinuous online monitoring of bushings provides real-time information which can result in the early detection of a possible failure. Challenge: A Major AlarmA prominent U.S. utility was looking for a way to improve system reliability for their 138kV assets. They researched and...
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...
A transformer relies on electromagnetic induction through coils to transfer electric energy between two or more circuits. Varying current in the transformer’s primary winding creates varying magnetic flux in the core, which produces varying electromotive force (EMF) or voltage in the...
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. Monitoring can vary greatly from nine gas to single gas systems to best suit the customers application when considering...
Introduction Fault type identification is an important step in dissolved gas analysis (DGA). When a significant amount fault gas production is detected in a transformer, we want to know what kind of physical condition could be responsible for the gassing. Knowing the type of fault can help to...
ABSTRACTHere we discuss the phenomenon of transformer inrush; what it is and its significance to transformer protection design. INTRODUCTIONA couple of years ago in this Transformer Special Edition, we wrote an article that covered the most used transformer protection schemes. As was pointed out...
