High Voltage
Use Of Vacuum As A Breaking Medium
SF6 and vacuum are the two most modern breaking techniques in the fields of Medium Voltage (from 1 to 52 kV) and High Voltage (> 72.5 kV). They appeared in… Read more
Dec 22, 2010 | By Edvard
Power Substation
Establishing New Power Substation
The construction of new substations and the expansion of existing facilities are common place projects in electric utilities. However, due to the complexity, very few utility employees are familiar with… Read more
Dec 20, 2010 | By Edvard
Energy and Power
Characteristics of Lightning Strokes
Lightning, one of Mother Nature’s most spectacular events, started to appear significantly demystified after Franklin showed its electric nature with his famous electrical kite experiment in 1752. Although a great… Read more
Dec 19, 2010 | By Edvard
High Voltage
Basics Of Subtransmission Systems
Subtransmission systems are those circuits that supply distribution substations. Several different subtransmission systems can supply distribution substations. Common subtransmission voltages include 34.5, 69, 115, and 138 kV. Higher voltage subtransmission… Read more
Dec 17, 2010 | By Edvard
Maintenance
Maintenance for UPS systems
Maintenance of the UPS consists of preventive and corrective maintenance. Preventive maintenance consists of a scheduled list of activities. Performing these activities keeps the UPS in good working order and… Read more
Dec 16, 2010 | By Edvard
Solar Power
Solar Power Tower
Solar power towers generate electric power from sunlight by focusing concentrated solar radiation on a tower mounted heat exchanger (receiver). The system uses hundreds to thousands of sun-tracking mirrors called… Read more
Dec 15, 2010 | By Edvard
Electric Motor
Keeping Motor Windings Dry
Special provision should be made to protect motor windings which operate in a damp atmosphere or are subject to condensation of moisture when out of service for long periods. Motors… Read more
Dec 14, 2010 | By Edvard
Low Voltage
Forms of Separation (2) – Fundamentals
In accordance with the Standard, separation of the various elements of an Assembly: busbars, functional units, terminals, can be claimed providing one or more of the following criteria are met:… Read more
Dec 13, 2010 | By Edvard
Cables
Shielding Of Power Cables
Medium and high-voltage power cables, in circuits over 2000 volts, usually have a shield layer of copper or aluminum tape or conducting polymer. If an unshielded insulated cable is in… Read more
Dec 12, 2010 | By Edvard
Hydropower
Hydro vs. Wind vs. Solar Power?
Matthew Stein, author of When Technology Fails: A Manual for Self-Reliance, Sustainability, and Surviving the Long Emergency wrestles with that very question in his book. Here’s an excerpt: No single… Read more
Dec 11, 2010 | By Edvard
Energy and Power
Sources Of The Electric Energy – Generation
There are a number of ways to produce electricity, the most common commercial way being the use of a synchronous generator driven by a rotating turbine. The combination is called… Read more
Dec 10, 2010 | By Edvard
High Voltage
IEC 62271-200 – HV Switchgear And Controlgear
Part 200: AC metal-enclosed switchgear and controlgear for rated voltages above 1 kV and up to and including 52 kV Switchgears are important nodal points in modern power distribution. Correspondingly… Read more
Dec 09, 2010 | By Edvard
Energy and Power
Historical Review of Power System Stability Problems
As electric power systems have evolved over the last century, different forms of instability have emerged as being important during different periods. The methods of analysis and resolution of stability… Read more
Dec 08, 2010 | By Edvard
Energy and Power
Time-Current Curves explained in details
Time-current curves are used to show how fast a breaker will trip at any magnitude of current. The following illustration shows how a time-current curve works. The figures along the… Read more
Dec 07, 2010 | By Edvard
Wind Power
Aerodynamics of Horizontal-Axis Wind Turbines
A wind turbine is a device for extracting kinetic energy from the wind. By removing some of its kinetic energy the wind must slow down but only that mass of… Read more
Dec 06, 2010 | By Edvard
