High Voltage
GIS vs AIS – Substation Earthing
Compressed SF6 gas used in MV and HV switchgears as an insulating medium has led to the development of compact gas-insulated substation (CIS) technology (figure 1). GIS , having many advantages over often used and conventional air-insulated substations (AIS), have… Read more
Sep 12, 2011 | By Edvard Csanyi
Lighting
Illuminance recommendations
Recommended minimum illuminances (E) for typical interior lighting tasks. The illuminances are aimed at a lighting level appropriate to the specific visual tasks to be performed in the space or in a part of the space. They do not include… Read more
Sep 10, 2011 | By Edvard Csanyi
High Voltage
What Is a Load Break Switch?
A load break switch is a disconnect switch that has been designed to provide making or breaking of specified currents. This is accomplished by addition of equipment that increases the operating speed of the disconnect switch blade and the addition… Read more
Sep 08, 2011 | By Edvard Csanyi
High Voltage
Oil-Filled Equipment in Substation – IEEE 980-1994 (R2001)
A number of electrical apparatus installed in substations are filled with oil that provides the necessary insulation characteristics and assures their required performance. Electrical faults in this power equipment can produce arcing and excessive temperatures that may vaporize insulating oil,… Read more
Sep 07, 2011 | By Edvard Csanyi
High Voltage
AIS – Air insulated substations
In large, modern AC power systems, the transmission and distribution systems function to deliver bulk power from generating sources to users at the load centers. Transmission systems generally include generation switchyards, interconnecting transmission lines, autotransformers, switching stations, and step-down transformers…. Read more
Sep 06, 2011 | By Edvard Csanyi
Power Substation
Animal deterrents and security in substation
The vast majority of electrical utility substations designed to transform transmission voltages to distribution class voltages employ an open-air design. The configurations may vary, but usually consist of equipment that utilizes polymer or porcelain insulators or bushings to create electrically… Read more
Sep 05, 2011 | By Edvard Csanyi
Energy and Power
Ohm’s Law – The Resistance
It is intuitive that voltage and current would be somehow related. For example, if the potential difference between two ends of a wire is increased, we would expect a greater current to flow, just like the flow rate of gas… Read more
Sep 02, 2011 | By Edvard Csanyi
Protection
Bus protection – Overcurrent differential
When selecting relays for bus protection, a major concern is the ability of the protective relaying scheme to restrain from tripping for close-in line faults. Tripping for bus faults, the reason for installing bus differential relaying, is less of a… Read more
Aug 31, 2011 | By Edvard Csanyi
Energy and Power
How reactive power is helpful to maintain a healthy system
We always tend to reduce reactive power to improve system efficiency. This is acceptable at some level. If the system is purely resistive or capacitance, it may cause problems in the Electrical system. AC systems supply or consume two kinds… Read more
Aug 29, 2011 | By Jignesh Parmar
Energy and Power
Difference between Power Transformer and Distribution Transformer
Power transformers are used in transmission network of higher voltages for step-up and step down application (400 kV, 200 kV, 110 kV, 66 kV, 33kV) and are generally rated above 200MVA. On the other hand, distribution transformers are used for… Read more
Aug 27, 2011 | By Jignesh Parmar
Energy and Power
Surge arrester types and auxiliary equipment
Nearly 100 years ago, electrode gaps (rod, sphere, or pipe) were used to limit overvoltages on equipment (Sakshaug, 1991). Some of these systems, particularly pipe gaps, may still be in service today. However, the characteristic of gap sparkover voltage vs…. Read more
Aug 25, 2011 | By Edvard Csanyi
Energy and Power
How to save electrical energy at home
In our home we use lot of electrical equipment like TV, Freeze, Washing machine, Mp3 player, music system, computer laptop. But we have not adequate knowledge for how to use this electrical equipment in proper way. Due to this ignorance… Read more
Aug 23, 2011 | By Jignesh Parmar
High Voltage
Capacitor protection by surge arresters – ABB
Generally speaking, capacitor protection by surge arresters has been a difficult task before ZnO arresters became available. The high discharge currents and possible energies associated with an arrester operation at a capacitor bank heavily stressed the spark gaps in a… Read more
Aug 22, 2011 | By Edvard Csanyi
Energy and Power
Autotransformers in few words
It is possible to obtain transformer action by means of a single coil, provided that there is a “tap connection” somewhere along the winding. Transformers having only one winding are called autotransformers, shown schematically in figure 1. An autotransformer has… Read more
Aug 19, 2011 | By Edvard Csanyi
Industrial Automation
How Stuxnet (PLC virus) spreads – Part 4
Continued from How Stuxnet (PLC virus) spreads – Part 3 » Read here Once the worm has a foothold in the Perimeter Network, it would attempt to infect any print servers and file servers it could discover. Next, the worm… Read more
Aug 18, 2011 | By Edvard Csanyi
