Protection
Using earth & phase directional protection where power flow direction might change
Directional protection relay is often used in all network parts in which the direction of flow of power might change, notably in the instance of a short circuit between phases or of an earthing fault (single phase fault). Directional protection… Read more
Jun 17, 2019 | By Edvard Csanyi
Energy and Power
The essentials of MV/HV magnetic voltage transformers
Magnetic voltage transformers are used to provide a secondary signal that is proportional to the actual prevailing primary value. These signals are used to supply measuring instruments, meters, relays and other similar apparatuses. The primary values measured are system currents… Read more
Aug 14, 2017 | By Edvard Csanyi
Testing and Commissioning
Testing of power transformer – Measurement of impedance voltage and load loss
The measurement is carried out to determine the load-losses of the transformer and the impedanse voltage at rated frequency and rated current. On Figure 1 above (Circuit for the impedance and load-loss measurement) there are following figures: G1 – Supply… Read more
Mar 12, 2014 | By Edvard Csanyi
Testing and Commissioning
Transformer Routine Test – Measurement of Voltage Ratio and Check of Phase Displacement
The no-load voltage ratio between two windings of a transformer is called turn ratio. The aim of measurement is: Confirming the no-load voltage ratio given in the customer order specifications, determining the conditions of both the windings and the connections… Read more
Mar 02, 2013 | By Edvard Csanyi
Energy and Power
Principles of Transformers in Parallel Connection
For supplying a load in excess of the rating of an existing transformer, two or more transformers may be connected in parallel with the existing transformer. The transformers are connected in parallel when load on one of the transformers is… Read more
Aug 06, 2012 | By Jignesh Parmar
Electrical Lectures
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. The vector group of the transformer is determined by the connection between the windings… Read more
Jun 03, 2012 | By Jignesh Parmar
