Per unit fault calculations is a method whereby system impedances and quantities are normalised across different voltage levels to a common base.  By removing...

Following on from my post on railway electrification voltages, I thought an introduction to traction substations would be a good idea. Traction substations...

IEC 62305 'Protection against lightning' requires a risk assessment be carried out to determine the characteristics of any lightning protection system...

Years ago I was told that you should always try to write the best report you can.  Many years later I still think on this as one of the better pieces of...

Resistors are electronic components that oppose the flow of current.  Manufactured in various types and ranges they have a wide application to electronics...

If you at all familiar with programs like office and outlook, then adding and editing posts is pretty straightforward and intuitive.  However, there are...

In three phase systems, the use of transformers with three windings (or legs) per side is common.  These three windings are often connected in delta or...

At the beginning of the year China put the world's first 1,000 kV UHV transmission system into operation. Transmitting power at over a million volts is...

The image (reproduced from IEC 60909) shows a typical fault in an ac system.  From the illustration it can seen that there is an initial dc component ...

The following tables provide quick order of magnitude fault levels for a a range of typical low voltage situations.