Extending the effective life of a transformer

  Power transformers are key components in any electrical network and to ensure the safe, reliable and optimum working life of the transformer, care is required to limit insulation moisture as one of the most important parameters that cause insulation degradation and reduction in service life [1]. There are also safe limits of moisture content […]

Live-line techniques in high voltage overhead transmission line repair

  by Patrick O’Halloran, City Power This short paper covers how live-line (energised) techniques can be utilised to restore supply as quickly as possible in the event that high voltage transmission towers have collapsed. Download the PDF

Electromagnetic environment around HVDC transmission lines

by Matthew Sibanda and Robert van Zyl, Cape Peninsula University of Technology and Nishanth Parus, Eskom The purpose of this paper is twofold. Firstly, an overview of the interaction between high voltage direct current (HVDC) transmission lines and the environment they are operated in is presented. Secondly, the equipment required to characterise this environment is […]

Protecting pole mounted MV transformers

by M du Preez and WJD van Schalkwyk, Eskom Unplanned outages often occur as a result of transformers, drop-out fuses and surge arresters which fail during lightning storms. MV drop-out fuses with upstream feeder protection need to be properly graded to ensure correct protection during both lightning and power frequency faults. Download the PDF

The influence of HVDC transmission on AC networks

Information from Cigré The use of HVDC links between regions within an AC network is becoming increasing important because of the growing challenge of network development. The lack of public acceptance of new overhead lines delays the process. Therefore, more and more underground connections are considered inside AC networks to replace traditional overhead lines, operating […]

Substation upgrading and refurbishment project

by Rui Marques, Roshqott Mogale City local municipality (MCLM) has awarded a R100-million project comprising the complete rehabilitation of 25 existing 33 kV and the construction of 13 new 33 kV feeders as well as grid reinforcement at the Condale main intake substation in Mogale City to a local company. Download the PDF

Smart grid: Global impact report overview

by Mike Rycroft, features editor Experts have discussed theoretical smart grid models for over a decade, but until now there has been no way to  benchmark results globally. Ventyx and ABB selected VaasaETT to develop a smart grid global impact report, a global report into smart grids and their outcomes. This article summarises the report. […]

How smart can the grid really be?

by Dale Pudney, HVT Power Systems and Luo Wei, NR Electric With the improvement of electronic communications and computing technology, it becomes possible to integrate and improve the capabilities of the protection and automation systems on our power grids. Download the PDF document

Back to the beginning through smart grid

by EK Onwunta and MTE Kahn, Cape Peninsula University of Technology In the beginning generation was local  and supplied local demand. That changed because of technological advancements with improved efficiency and economies of scale. Modern society is highly dependent on the availability of cheap and reliable electricity. A revival of interest in distributed generation implies […]