From the monthly archives: April 2013

We are pleased to present below all posts archived in 'April 2013'. If you still can't find what you are looking for, try using the search box.

Fault Calculation - Per Unit System

By Steven McFadyen on 3/27/2013 12:54 PM

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..


Fault Calculation - Symmetrical Components

By Steven McFadyen on 3/27/2013 12:52 PM

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..


Robotics - Home Innovations

By Steven McFadyen on 3/10/2013 11:50 AM

We have a sister note to this (Robots - Interesting Video), in which I have posted some videos of interesting robots developed by commercial corporations and institutions.  While these are great... read more..




Restricted Earth Fault Protection

The windings of many medium and small sized transformers are protected by restricted earth fault (REF) systems. The illustration shows the principal of...

Dielectric loss in cables

Dielectrics (insulating materials for example) when subjected to a varying electric field, will have some energy loss.   The varying electric field causes...

Induction Motor Equivalent Circuit

Induction motors are frequently used in both industrial and domestic applications.  Within the induction motor, an electrical current in the rotor is induced...

Photovoltaic (PV) Panel - Performance Modelling

In an earlier note on the site [Photovoltaic (PV) - Electrical Calculations], the theory of solar (PV) cell calculations was introduced.  In particular...

Inductance

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...

Fire Resistant and Fire Retardant Cables

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...

Aluminium Windings - Dry Type Transformers

The other day I was talking to a colleague who is a building services consultant.  Despite regularly specifying dry-type/cast resin transformers he was...

Fault Calculation - Symmetrical Components

For unbalance conditions the calculation of fault currents is more complex. One method of dealing with this is symmetrical components. Using symmetrical...

Cable Sizing Software

When sizing cables nearly, everyone uses some form of software. This ranges from homespun spreadsheets to complex network analyses software. Each has its...

Autonomous Vehicle Challenge

Two driverless and solar power vans have departed from Italy on their way to China via the silk road. During the 13,000 kM trip the vans will drive themselves...

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