Differential protection, the good old days
This morning I was explaining how differential protection works to a junior engineer. To give him something to read I opened up the NPAG (Network Protection...
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...
Questions - Reputation and Privilege
Our question and answer system while letting you do exactly what it says, is much more. It is a dynamic user driven system, where our users not only ask...
Operational Amplifier
The fundamental component of any analogue computer is the operational amplifier, or op amp. An operational amplifier (often called an op-amp,) is a high...
Capacitors - Energy Storage Application
Capacitors have numerous applications in electrical and electronic applications. This note examines the use of capacitors to store electrical energy....
Why a Sine Wave?
I received this question by email a few weeks. First thoughts was that it is a product of the mathematics of rotating a straight conductor in a magnetic...
Motor Starting - Introduction
Motor starting and its associated problems are well-known to many people who have worked on large industrial processes. However, these things are, of course...
Cable Sizing Software
When sizing cables nearly, everyone uses some form of software. This ranges from homespun spreadsheets to complex network analyses software. Each has its...
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...
DC Component of Asymmetrical Faults
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 ...