power systems loss

Completed and Authored by: Chetan C. Adalja M.L. Jain, Technology Department, EMCO Limited, Thane India INTRODUCTION The stray losses in a transformer comprise winding stray losses, viz. eddy loss and circulating current loss; the loss in the edge stack (smallest packet of the core limb); and the loss in structural parts, viz. frame, flitch plate and tank. Core loss at the impedance voltage being insignificantly low, is not considered in the present analysis. In case of large generator transformers, stray losses due to high current carrying leads also become significant.

LOADING POWER TRANSFORMERS BEYOND NAMEPLATE RATING:SIMULATION SOFTWARE VIDEO Power transsformers are one of the most critical asset in any power system network. Transformers undergoe different load cycles that vary depending the time of day and year in power system conditions. For example, the daily load cycle tends to increase during the early hours of the morning before people leave for work and in the evning after they arrive home. Similarly, a yearly load cycle during the hot summer months when high ambient temperature cause consumers to ramp up their air conditioners and use more electrical power. During contingecy conditions, single or variuos network elemaents such as transsmission lines, generators or transformers might be isolated from the power system. As a consequence,transformers can become overloaded by reaching magnitudes above its maximum nameplate capability affecting and possible reducing the overall life of the transformer.During transformer overloads, theextra pow

IEEE STD C57.93-1995: GUIDE FOR INSTALLATION OF LIQUID-IMMERSED POWER TRANSFORMERS This IEEE standard aims to show the appropriate way of shipping, handling, inspecting, installing, and maintaining liquid-immersed power transformers. Power transformers are defined in this guide to be above 501kVA and which its secondary voltage should be equal or above 1000V. Two sizes of transformers are basically discussed in this guide, those which are 10MVA and above with a primary voltage winding of 69kV and above and transformers which are 501kVA to 10MVA (oil or ail cooled) having a primary voltage winding of 69kV and below. 501kVA TO 10 MVA (OA) LIQUID-IMMERSED POWER TRANSFORMERS This type of transformers are said to be usually a station or pad-mount installed transformers. Its tanks are tightly sealed to preserve the liquid or inert gas used as insulation. Radiators which are usually provided by manufacturer for cooling can be welded directly to the tank. Transformers with lower capacity ar

K-FACTOR TRANSFORMER K factor has been a basis for measuring the capability of a transformer to carry nonlinear loads. It is the factor to determine whether the transformer can withstand transformer heating due to harmonic load currents. ANSI/IEEE Std.C57-110 is the primary reference when it comes to the discussion of k-factor in a transformer. Below are selected articles discussing the k-factor and the k-rated transformers. FAQs are also available for your reference to make yourself familiar with the nature of use of this k-factor for transformer. K-Factor Definition K-factor is a weighting of the harmonic load currents according to their effects on transformer heating, as derived from ANSI/IEEE C57.110. A K-factor of 1.0 indicates a linear load (no harmonics). The higher the K-factor, the greater the harmonic heating effects. When a non-linear load is supplied from a transformer, it is sometimes necessary to derate the transformer capacity to avoid overheating and subsequent ins

(From npsc2010.uceou.edu ) The performance of transformer, the most ancient power system static element, is affected due to presence of distortion in the input supply voltage and non-linearity in the load current. Due to extensive use of modern power electronics controlled devices, the degree of non-linearity in the load current has increased in recent years. 

(From http://www.metglas.com/ ) Metal alloys typically possess crystalline atomic structures in which individual atoms are arranged in ordered, repeating patterns. Amorphous-metal alloys differ from their crystalline counterparts in that they consist of atoms arranged in near random configurations devoid of long-range order.

Generally, two main types of losses exist during an electrical power transformation and are also inherent in every transformer. We have the load loss also known as the winding loss where this type of loss depends on the loading of the transformer, the higher the load, the higher the loss that it can generate. Also, we have the no-load loss also known as the core loss where this is type of loss is constant in every transformer regardless it is fully loaded or no-load at all.