Understanding Vector Group of Transformer (2)
Continued from first part Understanding Vector Group of Transformer (part 1) Vector Groups are the IEC method of categorizing the primary and secondary winding configurations of 3-phase transformers. Windings can… Read more
Jun 04, 2012 | By jiguparmar
Understanding Vector Group of Transformer (Part 1)
Three phase transformer consists of three sets of primary windings, one for each phase, and three sets of secondary windings wound on the same iron core. Separate single-phase transformers can… Read more
Jun 03, 2012 | By jiguparmar
Transformer Connection Star-Star
The windings of three phase transformers may be connected in by Y or Δ in the same manner as for three single phase transformer. Since the secondary’s may be connected either… Read more
May 23, 2012 | By jiguparmar
Special considerations when selecting transformer protection
Current transformer ratio selection and performance require special attention when applying transformer protection. Unique factors associated with transformers, including its winding ratios, magnetizing inrush current, and the presence of winding… Read more
May 19, 2012 | By Edvard Csanyi
Introduction to instrument transformers
Instrument transformers (ITs) are designed to transform voltage of current from the high values in the transmission and distribution systems to the low values that can be utilized by low… Read more
May 14, 2012 | By Edvard Csanyi
What is the best transformer coolant?
One of the main sources of losses and reasons for temperature rise in various parts of a transformer are the magnetic circuit and windings. So what are the actually reasons… Read more
Apr 20, 2012 | By Edvard Csanyi
Difference between step-up transformer and voltage amplifier
A step up transformer basically increases the magnitude of primary applied voltage that is increases the amplitude of voltage wave form. A voltage amplifier does exactly the same. Than a… Read more
Mar 17, 2012 | By Asif Eqbal
Sudden pressure relay in oil-filled power transformer
Internal arcing in an oil-filled power transformer can instantly vaporize surrounding oil, generating gas pressures that can cause catastrophic failure, rupture the tank, and spread flaming oil over a large… Read more
Mar 08, 2012 | By Edvard Csanyi
Voltage Instrument Transformer (VT) – Introduction
Instrument transformers are primarily used to provide isolation between the main primary circuit and the secondary control and measuring devices. This isolation is achieved by magnetically coupling the two circuits…. Read more
Feb 20, 2012 | By Edvard Csanyi
Purpose and maintenance of transformer bushings
The two most common types of bushings used on transformers as main lead entrances are solid porcelain bushings on smaller transformers and oil-filled condenser bushings on larger transformers. Solid porcelain… Read more
Feb 05, 2012 | By Edvard Csanyi
12 Main Classes Of Power Transformer
Transformers are used for a wide variety of purposes, with the complete range of voltage and power ratings as well as many special features for particular applications. The following covers… Read more
Jan 08, 2012 | By Edvard Csanyi
Using Core-Balance Current Transformer For Earth Fault Protection
The core-balance current transformer (or CBCT) is normally of the ring type, through the centre of which is passed cable that forms the primary winding. An earth fault relay, connected… Read more
Dec 28, 2011 | By Edvard Csanyi
Transformer Protection – Abstract from NEC
According to NEC 450.4, “each transformer 600 volts, nominal, or less shall be protected by an individual overcurrent device installed in series with each ungrounded input conductor.” Such overcurrent device… Read more
Dec 26, 2011 | By jiguparmar
Why and how much for fire protection of power plant?
Fire protection measures can be subdivided into life-safety and investment categories. Life-safety measures are considered to be mandatory by fire codes, building codes, or safety codes. As such, the codes… Read more
Dec 07, 2011 | By Edvard Csanyi
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… Read more
Nov 30, 2011 | By Edvard Csanyi