Power systems theory - generation, transmissions and distribution
There are a lot of interesting two page type notes on various medium voltage topics – switchgear, circuit breakers, bus systems etc. It is on the Siemens US site, so many of he note are IEEE/ANSI ... read more..
Following on from my post on railway electrification voltages, I thought an introduction to traction substation... read more..
This post is quick introduction and overview to different railway electrification voltages used in answer to a question sent in via email. While there are numerous voltages in use through out the w... read more..
This is the first of two posts on the resistance of conductors. In the next post I will look at the ac resistance, including skin effect and we deal with this. To get started, this post will look at the... read more..
A quick post in connection with an email question:
Live Tank - the circuit breaker the switching unit is located in an insulator bushing which is live at line voltage (or some voltage above g... read more..
The correct sizing of current transformers is required to ensure satisfactory operation of measuring instruments and protection relays. Several methods exist to size current transformers. This note will... read more..
Electrical engineering has a multitude of laws and theorems. It is fair to say the Ohm's Law is one of the more widely known; it not the most known. Developed in 1827 by Georg Ohm the law defines the re... read more..
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 and Automation Guide, by Areva) and turned to... read more..
While there are a vast array of cable insulation materials, these are often divided into two general types; Thermoplastic or Thermosetting. For example the current capacity determination of a cable in a... read more..
When selecting a generator, there are inherent limits on the active and reactive power which can be delivered. Generators are normally sized for a certain kW at a power factor of 0.8. However, to unders... read more..
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 field. While I guess this is the primary issue... read more..
One of the requirements to ensuring that everything works is to have equipment selected, manufactured and verified [tested] to IEC standards. Not all equipment...
American inventor Thomas Alva Edison was born in Milan, Ohio on February 11, 1847. He was the youngest of seven children and received little formal schooling...
I was reminded of Occam's Razor while reading a book. It's quite a simple principal of logic which has stood the test of time and is accepted as central...
Photovoltaic (PV) cells (sometimes called solar cells) convert solar energy into electrical energy. Every year more and more PV systems are installed...
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...
These lifts were first built in 1884 by J. E. Hall and called a paternoster ("Our Father", the first two words of the Lord's Prayer in Latin) due to its...
This is the first of two posts on the resistance of conductors. In the next post I will look at the ac resistance, including skin effect and we deal with...
If your are ever called out to troubleshoot something on your electrical system, one of the first things consider is the supply voltage. You want to ensure...
Various techniques exist to enable the correct selection of batteries for UPS applications. The procedure described below is one of the more common. ...
The mobile phone was born in 1973. They were the size of a brick and weighed a couple of kg, making them difficult to fit into your pocket. At a few thousand...
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