Power systems theory - generation, transmissions and distribution
Photovoltaic (PV) systems are typically more efficient when connected in parallel with a main power gird. During periods when the PV system generates energy this can be utilized and the grid energy u... read more..
Per unit fault calculations is a method whereby system impedances and quantities are normalised across different voltage levels to a common base. By removing the impact of varying voltages, the... read more..
For unbalance conditions the calculation of fault currents is more complex. One method of dealing with this is symmetrical components. Using symmetrical components, the unbalance system is broken dow... read more..
In the previous note we looked at the approach taken by the standard to the sizing of cables and illustrated this with an example. We then looked at one method of applying the standard and iden... read more..
Current transformers (CTs) are used to convert high level currents to a sma... read more..
IEC 60287 "Calculation of the continuous current rating of cables (100% load factor)" is the International Standard which defines the procedures and equations to be used in determining the ... read more..
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 (id.c.). This initial dc compo... read more..
One of the fundamental requirements of an alternating current distribution systems it to have the ability to change the magnitude of voltages. It is more efficient to transmit power at high voltag... read more..
I've recently come across this question a couple times browsing the internet. Decided to give a quick answer here. A rectifier transformer is a transformer which includes diodes or thyristors in the sam... read more..
Over the past year or so I've been involved in on going discussions related to referring fault levels from the secondary of a transformer to the primary side. While this is easy for some people to... read more..
Electromagnetic compatibility (EMC) is the study of coordinating electromagnetic fields give off equipment, with the withstand (compatibility) of other equipment within the vicinity. In it's simplest... read more..
Installation of a UPS can help in reducing problems due to issues with the power supply. A lot of people relate this to nine key issues. Depending on the type of UPS installed it is possible... read more..
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Electrical engineering is a field that covers a wide variety of sub-fields, including electricity and electronics. It is a field that goes back to the...
Three phase systems are derived from three separate windings, either connected in delta or star (wye). Each winding can be treated separately, leading...
Over recent years the Lithium Ion battery has become popular in applications requiring high power densities with small weight and footprint. Today Lithium...
Collection of links to various places with useful motor information. I’ll try and return to the page every now and again to update it with any motor notes...
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...
We have a sister note to this (Robots - Interesting Video), in which I have posted some videos of interesting robots developed by commercial corporations...
How often installations are inspected is up to the owner of the installation, provided such durations do not exceed any regulatory maximums in force. ...
Lamps are the essential part of any luminaire. These are the light generating components. Since the advent of electrical lighting in the middle of the...
A single phase system is perhaps the most common type of system most people are familiar with. This is what people have in their homes and what appliances...
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