Photovoltaic (PV) - Electrical Calculations
Photovoltaic (PV) cells (sometimes called solar cells) convert solar energy into electrical energy. Every year more and more PV systems are installed...
1,000 kV UHV First for China
At the beginning of the year China put the world's first 1,000 kV UHV transmission system into operation. Transmitting power at over a million volts is...
Random Numbers
Using laser optical pulses the random number generator utilizes the time between arrival of random photos to generate the numbers, ensuring true accuracy...
How a Digital Substation Works
Traditionally substations have used circuit breakers, current transformers (CT), voltage transformers (VT) and protection relays all wired together using...
Power Transformers - An Introduction
One of the fundamental requirements of an alternating current distribution systems it to have the ability to change the magnitude of voltages. It is more...
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.
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...
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...
Introduction to Current Transformers
Current transformers (CTs) are used to convert high level currents to a smaller more reasonable level for use as inputs to protection relays and metering...
Voltage Levels to IEC 60038
The standard aims to consolidate AC and traction voltages within the industry and defines the following bands:
band 1 - A.C. systems 100 V to 1...