Transformers
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 depend on the application, the size of the unit, and… Read more
Nov 28, 2010 | By Edvard Csanyi
Solar Power
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 be the preferred source of energy worldwide. Most modern nations… Read more
Nov 27, 2010 | By Edvard Csanyi
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 major consideration when designing coordinated power system protection. In order… Read more
Nov 27, 2010 | By Edvard Csanyi
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 this test is that its operating voltage of 500 to… Read more
Nov 26, 2010 | By Edvard Csanyi
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 this concept by the case of a sinusoidal voltage applied… Read more
Nov 23, 2010 | By Edvard Csanyi
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 important, and what parameters must be monitored. A brief explanation… Read more
Nov 21, 2010 | By Edvard Csanyi
Electrical Lectures
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 the necessity of reactive power that needs to be supplied… Read more
Nov 19, 2010 | By Edvard Csanyi
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 and reliability for the customer. As a complement to the… Read more
Nov 15, 2010 | By Edvard Csanyi
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 the relay location and the fault location. As the power… Read more
Nov 12, 2010 | By Edvard Csanyi
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 transformers are in SF6 gas inside grounded metal enclosures. The… Read more
Nov 10, 2010 | By Edvard Csanyi
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 1838, BS 5266–7: Lighting applications. Emergency lighting are the codes… Read more
Nov 10, 2010 | By Edvard Csanyi
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 gas space above the oil is provided with a pressure… Read more
Nov 08, 2010 | By Edvard Csanyi
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, the computers, the health-care systems, and the entertainment of modern… Read more
Nov 02, 2010 | By Edvard Csanyi
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: Short circuit disturbs the system environment around the fault point by causing a sudden drop in voltage, It requires a… Read more
Oct 28, 2010 | By Edvard Csanyi
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 winding material. The primary reason for choosing aluminum windings is… Read more
Oct 27, 2010 | By Edvard Csanyi
