Energy and Power
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 | By Edvard
Metering
Megger Tests
The insulation resistance meter test method for determining the condition of electrical insulation has been widely used for many years as a general nondestructive test method. A serious limitation of… Read more
Nov 26, 2010 | By Edvard
Energy and Power
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 | By Edvard
Energy and Power
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 | By Edvard
Energy and Power
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 | By Edvard
High Voltage
ABB – 145kV Compact indoor substation with Disconnecting CB
Turnkey 145 kV S/S project for Borlänge Energi, Sweden, emphasizing the advantages of ABB Disconnecting Circuit Breakers. Small footprint enables indoor air insulated Switchgear solutions, increasing the power substation availability… Read more
Nov 15, 2010 | By Edvard
Protection
Distance Relays
Distance relays respond to the voltage and current, i.e., the impedance, at the relay location. The impedance per mile is fairly constant so these relays respond to the distance between… Read more
Nov 12, 2010 | By Edvard
High Voltage
Gas-Insulated Substations – GIS
A gas-insulated substation (GIS) uses a superior dielectric gas, SF6, at moderate pressure for phase-tophase and phase-to-ground insulation. The high voltage conductors, circuit breaker interrupters, switches, current transformers, and voltage… Read more
Nov 10, 2010 | By Edvard
Lighting
Emergency lights
Indepandant emergency supply Many buildings must have some form of emergency lighting to come on if the electric supply to the ordinary lights fails. BS 5266: Emergency lighting, BS EN… Read more
Nov 10, 2010 | By Edvard
Transformers
Oil-Filled, Inert-Gas System
A positive seal of the transformer oil may be provided by an inert-gas system. Here, the tank is slightly pressurized by an inert gas such as nitrogen. The main tank… Read more
Nov 08, 2010 | By Edvard
Energy and Power
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 | By Edvard
Energy and Power
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 | By Edvard
Medium Voltage
Aluminum vs. Copper: Conductors in Low Voltage Dry Type Transformers
In North America, aluminum is the predominant choice of winding material for low-voltage, dry-type transformers larger than 15 kilovolt-amperes(kVA). In most other areas of the world, copper is the predominant… Read more
Oct 27, 2010 | By Edvard
Solar Power
Generating Power In The Future – Solar Wind Power
As the world discovers new ways to meet its growing energy needs, energy generated from Sun, which is better known as solar power and energy generated from wind called the… Read more
Oct 24, 2010 | By Edvard
Energy and Power
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 | By Edvard
