Power systems theory - generation, transmissions and distribution
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 merit in performing a more detailed study.&... read more..
Traditionally substations have used circuit breakers, current transformers (CT), voltage transformers (VT) and protection relays all wired together using copper cables. With advances in digital... read more..
Modelica is an open source (free) software language for modelling complex systems. Having never used it before, I thought I would download a development platform and see how it stacked up. This... read more..
Within Europe the European Committee for Electrotechnical Standardization (CENELEC) has standardised the both the designation and colour of cables. These are published in CENELEC document... read more..
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 mains (utility) supply. A UPS is inst... read more..
Power cables can basically be classified into earthed and unearthed cables, where earthed and unearthed refer to the application for which the cable is used. Earthed system refers to a three phase syste... read more..
Photovoltaic (PV) cells (sometimes called solar cells) convert solar energy into electrical energy. Every year more and more PV systems are installed. With this growing application, it's ... read more..
Fire resistant and fire retardant cable sheaths are design to resist combustion and limit the propagation of flames. Low smokes cables have a sheath designed to limit the amount of smoke and toxic ha... read more..
Capacitors have numerous applications in electrical and electronic applications. This note examines the use of capacitors to store electrical energy. The sidebar shows details of a typical c... read more..
If two dissimilar metals are touching and an external conducting path exists, corrosion of one the metals can take place. Moisture or other materials acting as an electrolyte between the metals... read more..
While not as popular as it once was, frame leakage protection does still have some use in some circumstances. In essence frame leakage is an earth fault type protection. A current transfo... read more..
Ever wondered what kind of power an aircraft uses when parked at the airport stand.
Normally the aircraft generates it own power, but when parked with the engines switched off power provided ... read more..
Multimeters are undoubtedly the most common item of electrical test equipment in use. Often it is the first piece of equipment people will turn to when...
I've been considering a blog on the 110 or 230 Volt issue for a while. While browsing the Internet I came across a great summary by Borat over at engineering...
Gauss's Electrical law defines the relation between charge ("Positive" & "Negative") and electric field. The law was initially formulated by Carl Friedrich...
A frequent problem in fault calculations is the obtaining of equipment parameters. While it is always preferable to use the actual parameters of the equipment...
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...
Battery powered cars are a hot topic and widely debated. The pros, cons, issues and time frames can be talked about endlessly. An article by the Telegraph...
Electric motors are one of the most widely used items of electrical equipment. Improving motor efficiency benefits include, reduced power demand, lower...
Estimating maximum demand is a topic frequently discussed. Working out how much power to allow for a building can be very subjective . Allowing too much...
Tapping your forearm or hand with a finger could soon be the way you interact with gadgets. A new technology created by Microsoft and Carnegie Mellon ...
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 ...
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