Power systems theory - generation, transmissions and distribution
Fault calculations are one of the most common types of calculation carried out during the design and analysis of electrical systems. These calculations involve determining the current flowing through... read more..
The following tables provide quick order of magnitude fault levels for a a range of typical low voltage situations.
Our cable sizing tool is one of the more popular tools on the site. The tool enables cables to be sized in compliance with BS 7671 (the IEE Wiring Regulations) and by implication IEC 60364.
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 are plugged in to. For larger amounts of power,... read more..
A fundamental concept behind the operation of alternating current systems is that voltage and current waveforms will be sinusoidal – a Sine Wave. This is best explained by considering how a coil of wire... read more..
Circuit breakers are switching devices whose primary function is to isolate parts of an electrical distribution system in the even of abnormal conditions. Abnormal conditions are generally caused ... read more..
This article gives an introduction to IEEE 485 method for the selection and calculation of battery capacity.
Variable frequency drives are widely used to control the speed of ac motors. This note looks at the mechanisms which enable d... read more..
Insulation on a motor prevents interconnection of windings and the winding to earth. When looking at motors, it is important to understand how the insulation functions and its practical applicatio... read more..
Coils of wire on the rotor carry a d.c. current which generates a magnetic field. A stator magnetic field is created using either permanent mag... read more..
The windings of many medium and small sized transformers are protected by restricted earth fault (REF) systems. The illustration shows the principal of REF protection. read more..
The widely used United Sates standard ANSI/IEEE C37.2 'Electrical Power System Device Function Numbers, Acronyms, and Contact Designations' deals with protective device function numbering and acronyms. ... read more..
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...
Photovoltaic (PV) cells (sometimes called solar cells) convert solar energy into electrical energy. Every year more and more PV systems are installed...
Various arguments exist around SF6 Gas Insulated (GIS) and Air Insulated (AIS) medium voltage switchgear. Recently we had to change a GIS design to AI...
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...
When sizing cables nearly, everyone uses some form of software. This ranges from homespun spreadsheets to complex network analyses software. Each has its...
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...
Just added a page to the tools, which will allow you to calculate the synchronous speed, slip and rated torque for an induction motor. Not a particularly...
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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...
The calculation of current in a three phase system has been brought up on our site feedback and is a discussion I seem to get involved in every now and...
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