High Voltage
HV Instrument Current Transformers in T&D
Electrical measurements on a high-voltage transmission and distribution systems cannot be made practically or safely with direct contact to the power carrying conductors. Instead, the voltages and currents must be brought down to a safe and usable level that can… Read more
Nov 23, 2012 | By Edvard Csanyi
Electric Motor
Stator Overheating Protection
All motors need protection against overheating resulting from overload, stalled rotor, or unbalanced stator currents. For complete protection, three-phase motors should have an overload element in each phase. This is because an open circuit in the supply to the power… Read more
Nov 19, 2012 | By Edvard Csanyi
Protection
Principles and Characteristics of Distance Protection
Distance relays are one of the most important protection elements in a transmission line. These relays may sometimes be set based in percentages of the line impedances, for example a typical setting for zone 1 is 80% of the impedance… Read more
Nov 13, 2012 | By Edvard Csanyi
Power Substation
Steps to Ensure Effective Substation Grounding (Part 2)
Continued from previous article: Steps to Ensure Effective Substation Grounding (1) In previous technical article (part 1) was explained first five steps that will ensure a reliable, safe and trouble-free substation grounding system. Here we will explain the last six steps:… Read more
Nov 10, 2012 | By Edvard Csanyi
Power Substation
Steps to ensure effective substation grounding (Part 1)
An electrical substation is a critical resource in a power system. Safe operation of a substation calls for a properly designed and installed grounding system. A well-designed grounding system will ensure reliable performance of the substation over its entire service life. How does… Read more
Nov 09, 2012 | By Edvard Csanyi
Energy and Power
Application of Circuit Breakers in IT Networks
IT supplies are used to prevent that a ground fault leads to immediate disconnection of the affected circuit like in a grounded system. Although a first ground fault results in a displacement of the potential of the entire supply, continued… Read more
Nov 03, 2012 | By Edvard Csanyi
Protection
Transformer Differential Protection Principles
Similar to bus protections, transformers are protected by differential relays. Inter-winding faults (short circuits) and ground faults within power transformers can be detected by this protection scheme. Failure to detect these faults and quickly isolate the transformer may cause serious… Read more
Nov 01, 2012 | By Edvard Csanyi
Energy and Power
Smart and safe protective shutdown of LV system with selectivity
From the point of view of the operational safety and reliability of an entire low-voltage installation, it is usually desirable to specifically isolate the part of a system affected by a short-circuit in order to prevent spreading of the fault. Selectivity… Read more
Oct 30, 2012 | By Edvard Csanyi
Protection
Overcurrent protection of transformer (NEC 450.3)
The overcurrent protection required for transformers is consider for Protection of Transformer only. Such overcurrent protection will not necessarily protect the primary or secondary conductors or equipment connected on the secondary side of the transformer. Introduction Overcurrent protection of transformers… Read more
Oct 08, 2012 | By Jignesh Parmar
Energy and Power
Disturbances In LV Networks Due To Surges
There are two types of surge: those generated by a lightning impact and those resulting from electrical switchgear switching operations. Surges resulting from lightning strokes (see figure below) can affect all electrical installations. Consequently, they are without doubt the main… Read more
Oct 06, 2012 | By Edvard Csanyi
Energy and Power
How to Protect Capacitor Banks?
Capacitor banks are used to compensate for reactive energy absorbed by electrical system loads, and sometimes to make up filters to reduce harmonic voltage. Their role is to improve the quality of the electrical system. They may be connected in… Read more
Oct 05, 2012 | By Edvard Csanyi
Energy and Power
Definitions of Abnormal Voltage Conditions
A sag is a temporary reduction in the normal AC voltage. A momentary sag is a variation, which lasts for a period of 0.5 cycle to about 2 s usually the result of a short circuit somewhere in the power system. Instances… Read more
Oct 02, 2012 | By Edvard Csanyi
Energy and Power
What is the difference between Bonding, Grounding and Earthing?
One of the most misunderstood and confused concept is difference between Bonding, Grounding and Earthing. Bonding is more clear word compare to Grounding and Earthing, but there is a micro difference between Grounding and Earthing. Earthing and Grounding are actually… Read more
Sep 27, 2012 | By Jignesh Parmar
Energy and Power
Inspection of Ground-Fault Protection Systems
This type of protection is defined by the NEC (National Electrical Code) to ensure protection against fire on electrical power installations. To ensure protection against fire: The NEC defines the use of an RCD with very low sensitivity called GFP IEC… Read more
Sep 25, 2012 | By Edvard Csanyi
Energy and Power
Surge Protection of Electronic Equipment
Generally, power circuits have components that have large thermal capacities, which make it impossible for them to attain very high temperatures quickly except during very large or long disturbances. This requires correspondingly large surge energies. Also, the materials that constitute… Read more
Sep 22, 2012 | By Edvard Csanyi
