Wind Variability
One of the most critical features of wind generation is the variability of wind. Wind speeds vary with time of day, time of year, height above ground, and location on… Read more
Nov 30, 2010 | By Edvard Csanyi
Danfoss – Max uptime for wind turbines
Located on top of towers that can extend 80 to 110 meters into the air, wind turbines are subjected to powerful operating forces. And because wind turbines are difficult to… Read more
Nov 29, 2010 | By Edvard Csanyi
ABB invests in renewable energy company
Zurich, Switzerland, November 24, 2010 – ABB, the global power and automation technology group, announced today it has invested about $13 million in Aquamarine Power, a Scottish company that has… Read more
Nov 29, 2010 | By Edvard Csanyi
Transformer Cooling Classes
Since no transformer is truly an “ideal” transformer, each will incur a certain amount of energy loss, mainly that which is converted to heat. Methods of removing this heat can… Read more
Nov 28, 2010 | By Edvard Csanyi
Should You Invest in Solar Power?
Solar power is quickly gaining popularity all over the globe. It is growing at a rate of 2% per year, and if the figures continue to grow, solar energy will… Read more
Nov 27, 2010 | By Edvard Csanyi
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 Csanyi
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 Csanyi
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 Csanyi
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 Csanyi
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 Csanyi
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 Csanyi
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 Csanyi
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 Csanyi
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 Csanyi
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 Csanyi