Energy and Power
31 practical do’s and don’ts to avoid loud transformer humming
The user thinking of loud transformer humming (practically noise) should start at the conceptual stage. If he can, he must consider if he has a noise problem before he specifies his transformer. If he does, a noise survey including frequency… Read more
Jan 06, 2017 | By Edvard Csanyi
Electrical Lectures
The essentials of AC power transformers for students and beginners
AC power transformers are one of the keys to allowing widespread distribution of electric power as we see it today. Transformers efficiently convert electricity to higher voltage for long distance transmission and back down to low voltages suitable for customer… Read more
Jul 15, 2016 | By Edvard Csanyi
Electrical Lectures
Practical Considerations of Transformer Heat and Noise
In addition to unwanted electrical effects, transformers may also exhibit undesirable physical effects, the most notable being the production of heat and noise. Transformer noise is primarily a nuisance effect, but heat is a potentially serious problem because winding insulation… Read more
Jul 31, 2015 | By Edvard Csanyi
Energy and Power
Ferroresonance Occurrence In Power Transformer
Ferroresonance occurs when line capacitance resonates with the magnetizing reactance of a core while it goes in and out of saturation. Ferroresonance is usually associated with potential transformers, which are instrument transformers that are used to develop voltages used by… Read more
May 10, 2013 | By Edvard Csanyi
Transformers
Importance of Transformer Inrush Current
When a transformer is taken off-line, there will be a certain amount of residual flux that can remain in the core due to the properties of the magnetic core material. The residual flux can be as much as 50 to… Read more
Dec 28, 2012 | By Edvard Csanyi
Transformers
How Power Transformer Produces Acoustical Noise?
This technical article explains the acoustic noise generating mechanism inside power transformers. Transformer noise has two sources: winding vibrations and core vibrations. The single most effective way to reduce windings noise is by having a good quality controlled winding process when… Read more
Dec 05, 2012 | By Edvard Csanyi
Protection
Transformer Differential Protection Principles
Similar to bus protections, transformers are protected by differential relays. Inter-winding faults (short circuits) and ground faults within power transformers can be detected by this protection scheme. Failure to detect these faults and quickly isolate the transformer may cause serious… Read more
Nov 01, 2012 | By Edvard Csanyi
Transformers
Transformers Are Never Silent
Yes, we all know that transformers are never silent. This is actually quite impossible, but in an environmentally aware, highly regulated world, the issue is not the level of noise, but its nature – and it’s very important. Transformers emit… Read more
Oct 29, 2012 | By Edvard Csanyi
Power Substation
Switching Impulse Test of the Transformer
The switching impulse test is applied to confirm the withstand of the transformer’s insulation against excessive voltages occurring during switching. During the switching impulse voltage test, the insulation between windings and between winding and earth and withstand between different terminals… Read more
Oct 11, 2012 | By Edvard Csanyi
Energy and Power
Transformer Heat, Copper and Iron Losses
The thermal ratings of a transformer are determined by the following three factors: The amount of heat produced in the windings and connections. The amount of heat produced in the iron core. How effectively the heat can be removed from… Read more
Sep 06, 2012 | By Edvard Csanyi
Transformers
Power Transformer Construction – The Core
The construction of a power transformer varies throughout the industry. The basic arrangement is essentially the same and has seen little significant change in recent years, so some ofthe variations can be discussed in this article. The core, which provides… Read more
Aug 23, 2012 | By Edvard Csanyi
Transformers
ZigZag Transformer Connection Overview
The zigzag connection of tranformer is also called the interconnected star connection. This connection has some of the features of the Y and the ∆ connections, combining the advantages of both. The zigzag transformer contains six coils on three cores…. Read more
Jun 15, 2012 | By Jignesh Parmar
Protection
Transformer and Transformer-Feeder Protection
The development of modern power systems has been reflected in the advances in transformer design. This has resulted in a wide range of transformers with sizes ranging from a few kVA to several hundred MVA being available for use in… Read more
Nov 30, 2011 | By Edvard Csanyi
Transformers
Sources of Sound in Transformers
Unlike cooling-fan or pump noise, the sound radiated from a transformer is tonal in nature, consisting of even harmonics of the power frequency. It is generally recognized that the predominant source of transformer noise is the core. The low frequency,… Read more
Nov 09, 2011 | By Edvard Csanyi
Metering
D’Arsonval Meter Movement
The most commonly used sensing mechanism used in DC ammeters, voltmeters, and ohm meters is a current-sensing device called a D’Arsonval meter movement (Figure 1). The D’Arsonval movement is a DC moving coil-type movement in which an electromagnetic core is… Read more
Mar 08, 2011 | By Edvard Csanyi
