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 | Edvard
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 | Edvard
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 | Edvard
Economic advantages of power factor correction
Power supply authorities apply a tariff system which imposes penalties on the drawing of energy with a monthly average power factor lower than 0.9. The contracts applied are different from… Read more
Dec 04, 2010 | Edvard
Electrical Certificates
There is often confusion about what is commonly referred to as an “Electrical Certificate”. There are essentially 3 types of documents or certificates. Each imply different type of certification. “Electrical… Read more
Dec 02, 2010 | Edvard
Electrical Power System Overcurrents
Electrical power systems must be designed to serve a variety of loads safely and reliably. Effective control of short-circuit current, or fault current as it is commonly called, is a… Read more
Nov 27, 2010 | Edvard
Harmonic Distortion
Harmonic distortion is caused by nonlinear devices in the power system. A nonlinear device is one in which the current is not proportional to the applied voltage. Figure 1 illustrates… Read more
Nov 23, 2010 | Edvard
Battery monitoring and maintenance guidelines
Battery monitoring has become a very popular topic, and many companies have either purchased equipment or are in the process of evaluating these systems. This article discusses why monitoring is… Read more
Nov 21, 2010 | Edvard
The Need for Reactive Power Compensation
Except in a very few special situations, electrical energy is generated, transmitted, distributed, and utilized as alternating current (AC). However, alternating current has several distinct disadvantages. One of these is… Read more
Nov 19, 2010 | Edvard
What is the cost of electricity?
Electrification in the early 20th century dramatically improved productivity and increased the well-being of the industrialized world. No longer a luxury – now a necessity – electricity powers the machinery,… Read more
Nov 02, 2010 | Edvard
Short-Circuit Electrical Currents
A short circuit is one of the major incidents affecting electrical systems. The consequences are often serious, if not dramatic: Although short circuits are less and less likely to occur… Read more
Oct 28, 2010 | Edvard
Power System Stability
Power system stability is the ability of the system, for a given initial operating condition, to regain a normal state of equilibrium after being subjected to a disturbance. Stability is… Read more
Oct 23, 2010 | Edvard
