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...
How to Size Current Transformers
The correct sizing of current transformers is required to ensure satisfactory operation of measuring instruments and protection relays. Several methods...
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...
What is an Open Delta Transformer
In three phase systems, the use of transformers with three windings (or legs) per side is common. These three windings are often connected in delta or...
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...
Lead us, Warleader
Delum, who had watched all in silence, his face empty of expression, now spoke in turn. ' "Lead us, Warleader, into glory."'
Reading is something I do...
IEC Document Designation
Often document control is dictated by project requirements, for example a particular organisation may have an existing numbering system. Existing company...
Voltage Drop in Installations - Concepts
Problems on achieving maximum voltage drop within an installation come up often. Depending where you live, local regulations will have different limits...
How to refer fault levels across a transformer
Over the past year or so I've been involved in on going discussions related to referring fault levels from the secondary of a transformer to the primary...
Generation of a Sine Wave
A fundamental concept behind the operation of alternating current systems is that voltage and current waveforms will be sinusoidal – a Sine Wave. This...