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..
Request to look at induction motor starting time have come up a few times on the site. Hopefully in this post, I give you guys some idea on how to calculate...
This article gives an introduction to IEEE 485 method for the selection and calculation of battery capacity.
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...
If two dissimilar metals are touching and an external conducting path exists, corrosion of one the metals can take place. Moisture or other materials...
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...
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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...
In a previous article I looked at the dc resistance of conductors and in this article we turn our attention to ac resistance. If you have not read the...
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...
Exposure to time varying magnetic fields, from power frequencies to the gigahertz range can have harmful consequences. A lot of research has been conducted...
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