Control Theory
Control theory looks at how systems work and are controlled from a mathematical view. This note gives a brief introduction to some of the concepts – more...
UPS - Uninterruptible Power Supply
A UPS is an uninterruptible power supply. It is a device which maintains a continuous supply of electrical power, even in the event of failure of the...
Wiki Depreciation
We have had the Wiki with us for a long time now, but at last I have decided to say bye bye – more details on why below.
Michael Faraday (the father of electrical engineering)
Famed English chemist and physicist Michael Faraday was born on September 22, 1791, in Newington Butts, a suburb of Surrey just south of the London Bridge...
Lighting Design - An Introduction
From the earliest times, humans have found ways to create light. Pre-historic peoples used natural materials (moss, grass, etc.) soaked in animal fat and...
How a Digital Substation Works
Traditionally substations have used circuit breakers, current transformers (CT), voltage transformers (VT) and protection relays all wired together using...
Variable Frequency Drive
Variable frequency drives are widely used to control the speed of ac motors. This note looks at the mechanisms which enable drive units to control the...
Introduction to Traction Substations
Following on from my post on railway electrification voltages, I thought an introduction to traction substations would be a good idea. Traction substations...
How to Size Current Transformers
The correct sizing of current transformers is required to ensure satisfactory operation of measuring instruments and protection relays. Several methods...
Medium Voltage Switchgear Room Design Guide
Many medium voltage (MV) indoor switchgear rooms exist worldwide. The complexity of these rooms varies considerably depending on location, function and...