How a Digital Substation Works
Traditionally substations have used circuit breakers, current transformers (CT), voltage transformers (VT) and protection relays all wired together using...
Earth Electrode Resistance
Earthing of electrical systems is essential for the correct functioning and the protecting of life and equipment in the event of faults. The earth electrode...
IEC 61439 - The Switchgear Standard
The new standard IEC 61439 replaces the old 60439. Compared to the old standard, the new 61439 is a more clearly defined and takes into account the assembly...
E-Ink
Before the technical, some general information. E-ink display are found in a lot of e-readers, some mobile phones and similar devices and the intent is...
Sony Pocket eBook Reader
For the past few years I have reading eBooks on my HTC touch phone. On and off I have debated buying an eReader and recently purchased a Sony PRS-300 ...
3 Phase Loads
Three phase systems are derived from three separate windings, either connected in delta or star (wye). Each winding can be treated separately, leading...
Maxwell's Equations - Introduction
Maxwell's Equations are a set of fundamental relationships, which govern how electric and magnetic fields interact. The equations explain how these fields...
Tip – Latitude and Longitude on Large Scale Plans
If you are working on a large plan, get the real coordinates [latitude, longitude] for two or more points and add them to the drawing. That way you can...
Voltage Levels – Confused?
I was having a conversation the other day about voltage levels. While everyone was in agreement that low voltage was 1000 V and less, there was more confusion...
Fault Calculation - Per Unit System
Per unit fault calculations is a method whereby system impedances and quantities are normalised across different voltage levels to a common base. By removing...