Abstracts of Papers Published by Other Researchers and Scientists Using SES Software
Measurement and Prediction of Microshock Currents and Voltages in an HV Laboratory
Presented at the 8th International Power Engineering Conference – IPEC2007, 3-6 December 2007, Singapore, IEEE Catalogue Number: 07EX1686C, pp. 223-228
Y. Ahmed, Graduate Student Member, IEEE, and S.M Rowland, Senior Member, IEEE
Abstract:
Microshocks are the low current, continuous discharges experienced by people capacitively coupled to high voltage equipment. The situations in which these discharges occur are complicated by the size and complexity of the high voltage equipment and the sensitivity of the person concerned. A simple model has been constructed in the commercial software package CDEGS. This has been used to model a geometrically simple object designed to represent a person adjacent to a high voltage tower. The predictions of the model are compared to experiments in a high voltage laboratory. The predictions are shown to be extremely accurate and suggest that CDEGS is capable of providing useful predictions in a more realistic scenario.
A simulation tool to predict the impact of soil topologies on coupling between a light rail system and buried third party infrastructure
Accepted to IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY
C. Charalambous, Member, IEEE, I. Cotton, Member, IEEE, P Aylott
Abstract:
The production of stray currents by DC Light Rail Systems leads to the corrosion of the supporting and third party infrastructure in close proximity to the rail system. This work simulates two parallel tracks that are occupied by two trains; one on each track. This type of modeling constitutes a realistic case study that is utilized to investigate the effect of soil topologies on the corrosion performance of a floating DC Light Rail System focusing on the supporting and third party infrastructure. The modeling technique used involves the accurate computation of the shunt and series parameters for use in a resistive type model using a commercially available software package. The results demonstrate the importance that soil resistivity has on the corrosion risk to traction system and third party infrastructure. Such information could ultimately be used to vary the level of stray current protection across a light rail system to ensure an consistent lifetime across the whole system.
Induced Voltages On Long Aerial And Buried Pipelines Due To Transmission Line Transients
Accepted to IEEE TRANSACTIONS ON POWER DELIVERY
Konstantinos Kopsidas , Ian Cotton, Member IEEE
Abstract:
In a previous paper, the voltage induced onto a 1km above ground pipeline by transmission line transients was shown to be significant in comparison to the induced voltage resulting from power system currents. This paper enhances the previous work in three distinct areas. Firstly, both aerial and buried pipelines are considered. Above ground pipelines are shown to be more at risk from transient induced voltages. Secondly, parallelisms of up to 10km are simulated. The results show that increasing parallelisms do not result in higher induced voltages once a critical distance has been reached. Thirdly, a backflashover from a tower in the vicinity to a pipeline is modeled. This allows conductive coupling to take place at the same time as inductive and capacitive coupling. Backflashovers are shown to be an important consideration in determining the maximum voltages observed on a nearby pipeline.
Modeling of Currents on Long Span, Dielectric Cables on HV Overhead Lines
IEEE TRANSACTIONS ON POWER DELIVERY, VOL. 22, NO. 2, APRIL 2007
Simon M. Rowland , Member, IEEE, Konstantinos Kopsidas, and Ian Cotton , Member, IEEE
Abstract:
It is well established that all-dielectric self-supporting cables on high-voltage overhead power lines can suffer from damage through the mechanism of dry-band arcing. A number of heuristics have evolved over the past 20 years and these are used to determine whether such cables are capable of reliable performance. A key element to planning is modeling the installation conditions. In addition to the geometry of the high-voltage line, such a model needs to consider the climatic environment and potential pollutants on the cable. In this paper, a model is built based on the commercial software current distribution, electromagnetic fields, grounding and soil structure analysis which is widely used in the power industry. The model developed is shown to be consistent with a number of previously published models. It is demonstrated that the relative sags of all-dielectric self-supporting cable and conductors are key to the severity of the installed situation. It is also shown that the towers do not need to be modeled for the most severe cases of high pollution, but are required for accuracy in medium and low pollution cases.
Comparison Of Transient And Power Frequency Induced Voltages On A Pipeline Parallel To An Overhead Transmission Line
IEEE TRANSACTIONS ON POWER DELIVERY, VOL. 22, NO. 3, JULY 2007
Ian Cotton, Member, IEEE, Konstantinos Kopsidas and Yang Zhang
Abstract:
An analysis of the voltages induced on a 1km pipeline by a parallel overhead transmission line has been carried out when the transmission line is carrying power frequency (50Hz) current and when it is subject to the propagation of a lightning or switching transient. A frequency based circuit modeling technique coupled with forward and inverse Fourier transforms is used to carry out this analysis. The relative severity of the induced voltages from power frequency current or transient (lightning/switching) overvoltages is illustrated using the simulation results. The results demonstrate the high relative magnitude of induced pipeline voltages that result from the propagation of lightning transients down overhead lines. The need to model the full overhead line for such an analysis is investigated as is the variation of the level of transmission line / pipeline coupling as a function of the local soil resistivity. Analysis of the level of induced voltage as a function of length of parallelism is also carried out.
Influence of soil structures on corrosion performance of floating-DC transit systems
IET Electr. Power Appl., Vol. 1, No. 1, January 2007
C. Charalambous and I. Cotton
Abstract:
The production of stray currents by DC-transit systems leads to the corrosion of nearby buried metallic structures, such as pipelines and cable sheaths. The paper details the corrosion performance of a DC transit system with a floating return rail, for a number of different soil resistivity structures: uniform, horizontal and vertical-layer models. This builds on previous work carried out in homogenous soils. It is shown that a variation in soil type along the route of a transit system can lead to high local leakage-current densities on buried metallic structures, increasing their vulnerability to corrosion damage.
Stray Current Control in DC Mass Transit Systems
IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY, VOL. 54, NO. 2, MARCH 2005
Ian Cotton , Member, IEEE, Charalambos Charalambous, Pete Aylott, and Petra Ernst
Abstract:
Stray current control is essential in direct current (DC) mass transit systems where the rail insulation is not of sufficient quality to prevent a corrosion risk to the rails, supporting and third-party infrastructure. This paper details the principles behind the need for stray current control and examines the relationship between the stray current collection system design and its efficiency. The use of floating return rails is shown to provide a reduction in stray current level in comparison to a grounded system, significantly reducing the corrosion level of the traction system running rails. An increase in conductivity of the stray current collection system or a reduction in the soil resistivity surrounding the traction system is shown to decrease the corrosion risk to the supporting and third party infrastructure.
|
