Energy and Power
Introduction to Static Protection Relays
The term ‘static’ implies that the relay has no moving parts. This is not strictly the case for a static relay, as the output contacts are still generally attracted armature relays. In a protection relay, the term ‘static’ refers to… Read more
Sep 21, 2012 | By Edvard Csanyi
Energy and Power
What is the purpose of equipotential bonding?
Equipotential bonding is essentially an electrical connection maintaining various exposed conductive parts and extraneous conductive parts at substantially the same potential. An earthed equipotential zone is one within which exposed conductive parts and extraneous conductive parts are maintained at substantially… Read more
Sep 20, 2012 | By Edvard Csanyi
High Voltage
Design of Overhead Transmission Line Foundation
The foundation is the name given to the system which transfers to the ground the various steady state (dead) and variable (live) loads developed by the transmission tower and conductors. Foundations may be variously subjected to compressive or bearing forces,… Read more
Sep 19, 2012 | By Edvard Csanyi
Transformers
Differences between Shunt Reactor and Power Transformer
Shunt Reactor and Transformer both appear similar in construction. Reactors are also often equipped with Fans for cooling similar to Power Transformers. However, there are major differences between the two. While a Power Transformer is designed for efficient power transfer… Read more
Sep 18, 2012 | By Edvard Csanyi
Energy and Power
Definition of Harmonics and Their Origin
The Fourier theorem states that all non-sinusoidal periodic functions can be represented as the sum of terms (i.e. a series) made up of: A sinusoidal term at the fundamental frequency, Definition of Harmonics and Their Origin Sinusoidal terms (harmonics) whose… Read more
Sep 17, 2012 | By Edvard Csanyi
Transmission and Distribution
Qatar General Electricity and Water Corporation – Recommendations for Safety Clearance
Service Vertical Clearance (Min) Water Line (to cross below EHV cable level) 0.5 Meter Sewerage Mains (to cross below EHV cable level) 1.0 Meter Drainage Mains (to cross below EHV cable level) 0.5 Meter Gas pipes 0.6 Meter Telephone lines… Read more
Sep 15, 2012 | By Jignesh Parmar
Energy and Power
Functions Performed by Electrical Switchgear
National and international standards define the method for making electrical distribution circuits as well as the purpose and functions of switchgear. There are three main functions, namely: Circuit protection takes three main fault types into account: Overloads, Short-circuits (Both of which… Read more
Sep 14, 2012 | By Edvard Csanyi
Metering
Analog signals in measurement and control of physical processes
Instrumentation is a field of study and work centering on measurement and control of physical processes. These physical processes include pressure, temperature, flow rate, and chemical consistency. An instrument is a device that measures and/or acts to control any kind… Read more
Sep 13, 2012 | By Edvard Csanyi
Energy and Power
Nikola Tesla – Everything is the Light
Once, in 1899, Nikola Tesla had an interview with certain journalist John Smith, when Tesla said “Everything is the Light“. In one of its rays is the fate of nations, each nation has its own ray in that great light source,… Read more
Sep 12, 2012 | By Edvard Csanyi
Electric Motor
LT / Medium / HT VFD Used In the Industry (part 2)
Consider the application of a drive to a cane milling unit where the speed is to be variable from full to half rated speed. The drive is to be capable of producing full rated torque over the entire speed range…. Read more
Sep 11, 2012 | By sprabakar22
Electric Motor
LT / Medium / HT VFD Used In the Industry (1)
In modern plants, there are number of drives like Milling Plant Drive, Hydraulic Drive, DC Motor Drive and AC Motor Drive of adequate capacities are available. There is lot of scope for improving the overall efficiency and saving the energy… Read more
Sep 10, 2012 | By sprabakar22
Electronics
Under the Hood of LEDs (Light Emitting Diodes)
LED lamps, or Light Emitting Diodes, are becoming more and more common. Having been used for some time in products such as digital watches, remote controls and brake lights, they are now being seen in many more applications such as… Read more
Sep 08, 2012 | By Paul Blythe
Hydropower
Things You Should Know Before Planning of Hydroelectric Facilities
Hydroelectric plants are located in geographic areas where they will make economic use of hydraulic energy sources. Hydraulic energy is available wherever there is a flow of liquid and head. Head represents potential energy and is the vertical distance through… Read more
Sep 07, 2012 | By Edvard Csanyi
Energy and Power
Transformer Heat, Copper and Iron Losses
The thermal ratings of a transformer are determined by the following three factors: The amount of heat produced in the windings and connections. The amount of heat produced in the iron core. How effectively the heat can be removed from… Read more
Sep 06, 2012 | By Edvard Csanyi
Protection
Transformer differential protection (ANSI 87T)
Transformer differential protection protects against short-circuits between turns of a winding and between windings that correspond to phase-to-phase or three-phase type short-circuits. If there is no earthing connection at the transformer location point, this protection can also be used to… Read more
Sep 05, 2012 | By Edvard Csanyi
