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...

ANSI (IEEE) Protective Device Numbering

The widely used United Sates standard ANSI/IEEE C37.2 'Electrical Power System Device Function Numbers, Acronyms, and Contact Designations' deals with...

Variable Frequency Drive

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...

Generator Sizing & Operation Limits

When selecting a generator, there are inherent limits on the active and reactive power which can be delivered. Generators are normally sized for a certain...

Wiki Depreciation

We have had the Wiki with us for a long time now, but at last I have decided to say bye bye – more details on why below.

Capacitors - Energy Storage Application

Capacitors have numerous applications in electrical and electronic applications.  This note examines the use of capacitors to store electrical energy....

Control Theory

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...

Differential protection, the good old days

This morning I was explaining how differential protection works to a junior engineer. To give him something to read I opened up the NPAG (Network Protection...

Fault Calculations - Typical Equipment Parameters

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...

Difference Between Live and Dead Tank Circuit Breakers

A quick post in connection with an email question: Live Tank - the circuit breaker the switching unit is located in an insulator bushing which is live...

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