Substation AC Auxiliary Supply For Inessential Loads

The purpose of auxiliary power supply systems is to cater for the necessary energy for the operation of primary and secondary devices at the substation. The auxiliary power systems are… Read more

Sep 30, 2015 | Edvard

FACTS Devices To Enhance Power System Performance

Flexible Alternating Current Transmission System (FACTS) simply refers to a combination of power electronics components with traditional power system components. They are intended to improve our power system reliability, power… Read more

Sep 28, 2015 | sajna soman

Acceptable levels of distortion in the mains supply system

In the mains supply system, harmonic voltage distortion is the consequence of the flow of harmonic currents through the impedances in the power supply circuit connected to the converter. A… Read more

Sep 26, 2015 | Edvard

Surge Protective Devices In TN Systems (Guide For Low Voltage Electricians)

For “protection against electric shock under fault conditions“ in TN systems, overcurrent and residual current devices have been approved. For the use of surge protective devices (SPDs) this means that… Read more

Sep 25, 2015 | Edvard

Analysis of pole-mounted MV/LV transformer grounding

Let’s discuss in some detail the reasons for the grounding philosophy adopted for pole-mounted MV/LV transformer substations illustrated in Figure 0. Contents: LV grounding MV grounding Combined MV/LV grounding Separate… Read more

Sep 23, 2015 | Edvard

Substation DC Auxiliary Supply – Battery And Charger Applications

Power substation can have one or several DC systems. Factors affecting the number of systems are the need of more than one voltage level and the need of duplicating systems…. Read more

Sep 21, 2015 | Edvard

Voltage Drop Calculations For Engineers – Beginners

Voltage drop calculations using the DC-resistance formula are not always accurate for AC circuits, especially for those with a less-than-unity power factor or for those that use conductors larger than 2… Read more

Sep 19, 2015 | Edvard

Guidelines To Residential Room Lighting

Architects of development houses usually select the locations for switches, receptacles, and luminaires at a quality and price level determined by the builder. However, purchasers of architect-designed, custom-built homes usually… Read more

Sep 18, 2015 | Edvard

4 Factors To Consider When Selecting a Sectionalizer

Sectionalizers are (beside overcurrent relays, reclosers and fuses) one of the most used for distribution system protection. A sectionalizer is a device that automatically isolates faulted sections of a distribution… Read more

Sep 16, 2015 | Edvard

SF6 or Vacuum MV Circuit Breaker In Specific Switching Applications

Many years of experience in developing both SF6 and vacuum medium-voltage circuit breakers has yielded up ample evidence that neither of the two technologies is generally better than the other,… Read more

Sep 14, 2015 | Edvard

6 Customer Requirements For a Generator Regarding Power Demand

To select an on-site engine/generator sets (gensets), you’ll need to determine the power demand requirements which must be met under operating conditions, of course. Let’s talk about six recognized customer genset… Read more

Sep 12, 2015 | Edvard

5 Steps To Safely Shutdown a Large Generator

Normally, units are removed from service through operator initiation of distributed control system (DCS) commands or turbine trip buttons that shutdown the prime mover. Closure of steam or fuel valves… Read more

Sep 11, 2015 | Edvard

Modernizing An Old Hardwired Relay Logic With Modern PLC System

This technical article presents the modernization of a machine control system that will be changed from an old hardwired relay logic to PLC programmed logic. The field devices to be… Read more

Sep 09, 2015 | Edvard

Selection of a suitable softstarter for application with conveyor belts

Conveyor belts can have a lot of different looks and directions of use. It is a typical constant torque load with low to high braking torque depending on how heavy… Read more

Sep 07, 2015 | Edvard

The Basics of Electrical Bus Protections

When we examine electrical protection schemes, the best place to start is with electrical bus protections, as they are the easiest to protect. They utilize the fundamental concept of the overcurrent relay (Figure 1)…. Read more

Sep 05, 2015 | Edvard