Protection
Delayed Auto-Reclosing On EHV Systems
On highly interconnected transmission systems, where the loss of a single line is unlikely to cause two sections of the system to drift apart significantly and lose synchronism, delayed auto-reclosing can be employed. Dead times of the order of 5s-60s are commonly used…. Read more
Aug 11, 2012 | By Edvard Csanyi
High Voltage
Primary Distribution Voltage Levels
Most distribution voltages are between 4 and 35 kV. In this article, unless otherwise specified, voltages are given as line-to-line voltages; this follows normal industry practice, but it is sometimes a source of confusion. The four major voltage classes are… Read more
Aug 10, 2012 | By Edvard Csanyi
High Voltage
The Structure Of Power System
An interconnected power system is a complex enterprise that may be subdivided into the following major subsystems: Generation Subsystem Transmission and Subtransmission Subsystem Distribution Subsystem Utilization Subsystem Generation subsystem includes generators and transformers. An essential component of power systems is… Read more
Aug 09, 2012 | By Edvard Csanyi
Energy and Power
Principles of Transformers in Parallel Connection (part 2)
In ideal parallel operating of power transformers, the current in each transformer is directly proportional to its capacity, and the arithmetic sum equals one-half of the total current. This is rarely accomplished because to minor discrepancies in transformers. Nonetheless, some… Read more
Aug 08, 2012 | By Jignesh Parmar
Electric Motor
Basics of 3-phase Induction Motor (part 4)
When a motor is expected to operate in unfavorable conditions such as: Intermittent overloading Higher ambient temperatures A restricted temperature rise as for a spinning mill, A refinery or a hazardous area Frequent starts, stops and reverses or any such… Read more
Aug 07, 2012 | By Asif Eqbal
Energy and Power
Principles of Transformers in Parallel Connection
For supplying a load in excess of the rating of an existing transformer, two or more transformers may be connected in parallel with the existing transformer. The transformers are connected in parallel when load on one of the transformers is… Read more
Aug 06, 2012 | By Jignesh Parmar
Energy and Power
Reliability of Compressed Air Energy Storage Plant
As the name implies, the compressed air energy storage (CAES) plant uses electricity to compress air which is stored in underground reservoirs. When electricity is needed, this compressed air is withdrawn, heated with gas or oil, and run through an expansion turbine… Read more
Aug 04, 2012 | By Edvard Csanyi
Electric Motor
Basics of 3-phase Induction Motor (part 3)
Continued fro second part – Basics of 3-phase Induction Motor (part 2) Technical data to be specified by purchaser before purchasing a 3 phase induction motor: No. Technical data to be specified Data 1. General data about ambient temperature and… Read more
Aug 03, 2012 | By Asif Eqbal
Electric Motor
Basics of 3-phase Induction Motor (part 2)
Continued from first part – Basics of 3-phase Induction Motor (part 1) For the purpose of standardization, the preferred rated voltages of three phase induction motor shall be in accordance with IS 12360: 1988. The voltages for three phases, 50… Read more
Aug 02, 2012 | By Asif Eqbal
Electric Motor
Basics of 3-phase Induction Motor (part 1)
This article will deal with those concepts of 3 phase induction motor which are essential prerequisite for proper selection, procurement, installation and maintenance of the same. Before any actual discussion on motor is started It will better to have a… Read more
Aug 01, 2012 | By Asif Eqbal
Cables
Sizing and protection of the neutral conductor (2)
Continued from the first part – Sizing and Protection of the Neutral Conductor (1) If the neutral conductor is correctly sized (including harmonics), no specific protection of the neutral conductor is required because it is protected by the phase protection. If… Read more
Jul 31, 2012 | By Edvard Csanyi
Cables
Sizing and protection of the neutral conductor (1)
Sizing (c.s.a.) and the protection of the neutral conductor, apart from its current-carrying requirement, depend on several factors, namely: The type of earthing system, TT, TN, etc. The harmonic currents The method of protection against indirect contact hazards according to… Read more
Jul 30, 2012 | By Edvard Csanyi
Energy and Power
Guidelines to Visual inspection of Electrical Installations
In general terms we are inspecting the installation with regard to personal safety, equpment age, deterioration, equipment corrosion and overload. Suitability and external influence to the power system should also be included. At this point it is a good idea to… Read more
Jul 28, 2012 | By Edvard Csanyi
Cables
Types of Cable Installations in Electrical Network
There are a variety of ways to install power distribution cables. Each method ensures distribution of power with a unique degree of reliability, safety, economy, and quality for any specific set of conditions. These conditions include the electrical characteristics of… Read more
Jul 27, 2012 | By Edvard Csanyi
Energy and Power
Overvoltages in the IT system
Electrical networks can be subject to overvoltages of varying origins. Some overvoltages, such as differential mode ones (between live conductors) affect all the earthing systems. This section is particularly concerned with common mode overvoltages, which mainly affect the IT system… Read more
Jul 26, 2012 | By Edvard Csanyi
