Power systems theory - generation, transmissions and distribution
The following tables provide quick order of magnitude fault levels for a a range of typical low voltage situations.
Per unit fault calculations is a method whereby system impedances and quantities are normalised across different voltage levels to a common base. By removing...
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...
Working in the vicinity of electrical equipment poses an hazard. In addition to electric shock hazard, fault currents passing through air causes Arc Flash...
Many questions sent in to the site are in connection with motor starting and in particular star-delta. For all but the simplest application, there is...
When current flows within a wire, a magnetic field is created. The potion of this magnetic field perpendicular to the wire is called the magnetic flux...
If you at all familiar with programs like office and outlook, then adding and editing posts is pretty straightforward and intuitive. However, there are...
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...
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...
If you want to check a circuit is dead (not live), you should always use the three point method. First check a known live circuit, then check the dead...
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