Konstantinos Kopsidas - Academia.edu (original) (raw)

Papers by Konstantinos Kopsidas

Research paper thumbnail of Evaluating Aeolian Vibration Performance of High-Temperature Low-Sag OHL Conductors

IEEE Transactions on Power Delivery

High-Temperature Low-Sag (HTLS) conductor technologies are often implemented, among many approach... more High-Temperature Low-Sag (HTLS) conductor technologies are often implemented, among many approaches, for optimizing the overhead lines utilization. The advancements of HTLS conductors are based on the differences in core and aluminum properties and installation procedures. This non-linear conductor behavior, although considered in the sag-tension calculations, by implementing the knee-point temperature, is often omitted from the aeolian vibration calculations. To understand the implications of the complex HTLS conductor structure on vibrations, a new calculation approach is proposed in this paper to quantify the effect of installation and operating conditions on the performance of any HTLS conductor. The proposed method conceives a prediction lay area that estimates where the actual field data are expected to lay, and is validated with good accuracy against the field data from ACSR, ACCC, and GZTACSR. The developed model enables the prediction of non-homogeneous (composite) conductors and should be implemented at above knee-point operating temperatures with zero aluminum tensions

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Research paper thumbnail of Study of the Flow Around a Heated Cylinder in Mixed Convection Regime

Direct and Large-Eddy Simulation XI, 2019

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Research paper thumbnail of Evaluating the effectiveness of a “With Industrial Experience” programme in Electrical and Electronic Engineering

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Research paper thumbnail of Finite element modelling of aeolian vibrations on stranded high-voltage OHL conductors

The problem of Aeolian vibrations has been studied in indoor test-spans for many years. Its relev... more The problem of Aeolian vibrations has been studied in indoor test-spans for many years. Its relevant standard experimentations have resulted in introducing the Energy Balance Method (EBM) which is the most commonly implemented method in the industry. Besides conductor properties, aerodynamic forces (Lift and Drag forces) acting on the conductor are the main input data for the EBM. The existing models frequently use experimental data of Lift and Drag forces for a cylinder. To further investigate the capabilities of windconductor interaction numerical modelling, it is useful to take advantage of Finite Element Modelling techniques. This paper simulates the wind flow around single OHL conductors with different outer layer stranding shapes and sizes utilizing COMSOL Multiphysics software. The simulations are based on solving the Navier-Stokes equation to compute the aerodynamic forces by integration of the pressure and shear forces within the boundaries of the conductor geometry. The numerical model computes the aerodynamic forces for three conductor geometries including smooth-surface, round-stranded, and trapezoidal stranding shapes. The numerically obtained solutions show that less aerodynamic forces are experienced by rounds and trapezoids compared to the cylinder geometry. This observation is true for high Reynolds numbers.

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Research paper thumbnail of Reliability evaluation framework incorporating energy storage systems

2017 Nineteenth International Middle East Power Systems Conference (MEPCON), 2017

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Research paper thumbnail of Modeling Multi-Layer OHL Conductors Undergoing Wind-Induced Motion

IEEE Access, 2020

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Research paper thumbnail of Evaluation of Demand Response on System Reliability and Cable Aging

International Journal on Advanced Science, Engineering and Information Technology, 2018

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Research paper thumbnail of Power Network Reliability Framework for Integrating Cable Design and Ageing

IEEE Transactions on Power Systems, 2017

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Research paper thumbnail of Impact of thermal uprating and emergency loading of OHL networks on interconnection flexibility

2016 18th Mediterranean Electrotechnical Conference (MELECON), 2016

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Research paper thumbnail of Optimal Demand Response Scheduling With Real-Time Thermal Ratings of Overhead Lines for Improved Network Reliability

IEEE Transactions on Smart Grid, 2016

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Research paper thumbnail of Overhead line design considerations for conductor creep mitigation

IET Generation, Transmission & Distribution, 2016

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Research paper thumbnail of A probabilistic indicator of the optimal operator action time under short-time emergency line loadings

2015 IEEE Eindhoven PowerTech, 2015

This paper introduces the concept of a probabilistic indicator to aid power system operator decis... more This paper introduces the concept of a probabilistic indicator to aid power system operator decision making during short-time emergency loadings stemming from operational uncertainty. It is based on a state based Monte Carlo sampling method and is thus able to capture the stochastic nature of power system operation. The methodology developed within this paper also incorporates conductor properties and operation by integrating dynamic thermal rating (DTR) data on the premise that DTR will be a key component of the smart grid in enabling smarter rating of power lines. The DTR weather is modeled as a Markovian process to account for the transitions between weather states. This methodology is tested and validated on the 24 bus IEEE-RTS in order to demonstrate the indicator's ability to evaluate areas of risk as well as opportunity in regard to the increase of overloading durations for a given maximum operating temperature and system operation state.

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Research paper thumbnail of Students' Perceptions of the ‘With Industrial Experience’ Degree Pathway in Electrical and Electronic Engineering

The International Journal of Electrical Engineering & Education, 2013

This paper presents the ‘With Industrial Experience’ programme offered as an option to undergradu... more This paper presents the ‘With Industrial Experience’ programme offered as an option to undergraduate students in the School of Electrical and Electronic Engineering at the University of Manchester, usually between their second and third year of study. Our focus is on the students' perceptions of the programme drawing on eight interviews with students who had already completed the course. By highlighting students' view of the benefits and also limitations of the programme we hope to inform our immediate plans for improvement of the course as well as the practice of others with similar programmes, globally.

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Research paper thumbnail of MOPSO using probabilistic and deterministic criteria based on OHL's thermal ratings

2014 Power Systems Computation Conference, 2014

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Research paper thumbnail of Reliability evaluation of demand response and TVTR considering the cost of interruptions

IEEE PES Innovative Smart Grid Technologies, Europe, 2014

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Research paper thumbnail of Risk assessment of smart energy transfer in distribution networks

IEEE PES Innovative Smart Grid Technologies, Europe, 2014

ABSTRACT Dynamic (or real-time) thermal rating (which utilizes actual weather conditions in order... more ABSTRACT Dynamic (or real-time) thermal rating (which utilizes actual weather conditions in order to more accurately model electro-thermal coordination behaviour of high voltage conductors) promises to play a vital role in the planning of energy transmission of future smart power systems. This paper investigates the adequacy impacts of real-time line thermal ratings (of different underground distribution network cabling systems), accounting for the following system risk issues: line losses and the risk of aging. The aim is to propose a new technique of assessing the reliability of distribution systems when cable-based line time varying thermal rating (TVTR) is implemented. This technique is illustrated through the reliability performance evaluation of a distribution system under a variety of cabling system configurations: XLPE; EPR and Solid paper insulated power cables; and the nine Standard Duct installation conditions. Concomitantly, the risk of aging the cable assets (RCAI) is evaluated in order to enhance planning decisions. Consequently, these probabilistic assessments reveal that oil pressure pipe-type cable ducting for an XLPE cable type has the lowest risk of aging the asset on the network; while Solid paper type cable installed in a fibre duct will experience the highest aging risk.

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Research paper thumbnail of Assessing optimal conductor utilization under N-1 overload security studies

2013 IEEE Grenoble Conference, 2013

ABSTRACT Elevated temperature operation (ETO) is as an attractive way of enabling better utilizat... more ABSTRACT Elevated temperature operation (ETO) is as an attractive way of enabling better utilization of existing transmission conductor assets especially during power system contingencies. However, due to the lack of Overhead Line conductor (OHLC) condition data, the present ETO ratings, short-term emergency (STE) and long-term emergency (LTE) ratings, are extremely conservative and inflexible. Furthermore, due to lack of sufficient historical operational data and algorithms, planners are unable to develop tools that enable increased and smarter utilization of the OHLC. The proliferation of modern real-time rating and other smart grid instrumentation allows for the use of historical data for planning purposes. On this basis, this paper presents how, in combination with OHL planning information, historical data can be utilized to develop improved operation guidance that accounts for the actual condition (ageing) of the OHLC. Therefore, it can be asserted that by knowing the OHLC condition, operators can flexibly make reliable cost effective decisions and thus be able to manage their OHL assets. Results are presented on a modified IEEE 24-bus RTS, implementing OHL properties into the analysis.

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Research paper thumbnail of Probabilistic assessment of impacts of real-time line ratings on distribution networks

2014 International Conference on Probabilistic Methods Applied to Power Systems (PMAPS), 2014

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Research paper thumbnail of Assessing the power transfer performance of a lattice tower overhead line system

IET Generation, Transmission & Distribution, 2013

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Research paper thumbnail of Evaluating opportunities for increasing power capacity of existing overhead line systems

IET Generation, Transmission & Distribution, 2011

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Research paper thumbnail of Evaluating Aeolian Vibration Performance of High-Temperature Low-Sag OHL Conductors

IEEE Transactions on Power Delivery

High-Temperature Low-Sag (HTLS) conductor technologies are often implemented, among many approach... more High-Temperature Low-Sag (HTLS) conductor technologies are often implemented, among many approaches, for optimizing the overhead lines utilization. The advancements of HTLS conductors are based on the differences in core and aluminum properties and installation procedures. This non-linear conductor behavior, although considered in the sag-tension calculations, by implementing the knee-point temperature, is often omitted from the aeolian vibration calculations. To understand the implications of the complex HTLS conductor structure on vibrations, a new calculation approach is proposed in this paper to quantify the effect of installation and operating conditions on the performance of any HTLS conductor. The proposed method conceives a prediction lay area that estimates where the actual field data are expected to lay, and is validated with good accuracy against the field data from ACSR, ACCC, and GZTACSR. The developed model enables the prediction of non-homogeneous (composite) conductors and should be implemented at above knee-point operating temperatures with zero aluminum tensions

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Study of the Flow Around a Heated Cylinder in Mixed Convection Regime

Direct and Large-Eddy Simulation XI, 2019

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Evaluating the effectiveness of a “With Industrial Experience” programme in Electrical and Electronic Engineering

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Finite element modelling of aeolian vibrations on stranded high-voltage OHL conductors

The problem of Aeolian vibrations has been studied in indoor test-spans for many years. Its relev... more The problem of Aeolian vibrations has been studied in indoor test-spans for many years. Its relevant standard experimentations have resulted in introducing the Energy Balance Method (EBM) which is the most commonly implemented method in the industry. Besides conductor properties, aerodynamic forces (Lift and Drag forces) acting on the conductor are the main input data for the EBM. The existing models frequently use experimental data of Lift and Drag forces for a cylinder. To further investigate the capabilities of windconductor interaction numerical modelling, it is useful to take advantage of Finite Element Modelling techniques. This paper simulates the wind flow around single OHL conductors with different outer layer stranding shapes and sizes utilizing COMSOL Multiphysics software. The simulations are based on solving the Navier-Stokes equation to compute the aerodynamic forces by integration of the pressure and shear forces within the boundaries of the conductor geometry. The numerical model computes the aerodynamic forces for three conductor geometries including smooth-surface, round-stranded, and trapezoidal stranding shapes. The numerically obtained solutions show that less aerodynamic forces are experienced by rounds and trapezoids compared to the cylinder geometry. This observation is true for high Reynolds numbers.

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Reliability evaluation framework incorporating energy storage systems

2017 Nineteenth International Middle East Power Systems Conference (MEPCON), 2017

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Modeling Multi-Layer OHL Conductors Undergoing Wind-Induced Motion

IEEE Access, 2020

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Evaluation of Demand Response on System Reliability and Cable Aging

International Journal on Advanced Science, Engineering and Information Technology, 2018

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Power Network Reliability Framework for Integrating Cable Design and Ageing

IEEE Transactions on Power Systems, 2017

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Impact of thermal uprating and emergency loading of OHL networks on interconnection flexibility

2016 18th Mediterranean Electrotechnical Conference (MELECON), 2016

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Optimal Demand Response Scheduling With Real-Time Thermal Ratings of Overhead Lines for Improved Network Reliability

IEEE Transactions on Smart Grid, 2016

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Overhead line design considerations for conductor creep mitigation

IET Generation, Transmission & Distribution, 2016

Bookmarks Related papers MentionsView impact

Research paper thumbnail of A probabilistic indicator of the optimal operator action time under short-time emergency line loadings

2015 IEEE Eindhoven PowerTech, 2015

This paper introduces the concept of a probabilistic indicator to aid power system operator decis... more This paper introduces the concept of a probabilistic indicator to aid power system operator decision making during short-time emergency loadings stemming from operational uncertainty. It is based on a state based Monte Carlo sampling method and is thus able to capture the stochastic nature of power system operation. The methodology developed within this paper also incorporates conductor properties and operation by integrating dynamic thermal rating (DTR) data on the premise that DTR will be a key component of the smart grid in enabling smarter rating of power lines. The DTR weather is modeled as a Markovian process to account for the transitions between weather states. This methodology is tested and validated on the 24 bus IEEE-RTS in order to demonstrate the indicator's ability to evaluate areas of risk as well as opportunity in regard to the increase of overloading durations for a given maximum operating temperature and system operation state.

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Students' Perceptions of the ‘With Industrial Experience’ Degree Pathway in Electrical and Electronic Engineering

The International Journal of Electrical Engineering & Education, 2013

This paper presents the ‘With Industrial Experience’ programme offered as an option to undergradu... more This paper presents the ‘With Industrial Experience’ programme offered as an option to undergraduate students in the School of Electrical and Electronic Engineering at the University of Manchester, usually between their second and third year of study. Our focus is on the students' perceptions of the programme drawing on eight interviews with students who had already completed the course. By highlighting students' view of the benefits and also limitations of the programme we hope to inform our immediate plans for improvement of the course as well as the practice of others with similar programmes, globally.

Bookmarks Related papers MentionsView impact

Research paper thumbnail of MOPSO using probabilistic and deterministic criteria based on OHL's thermal ratings

2014 Power Systems Computation Conference, 2014

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Reliability evaluation of demand response and TVTR considering the cost of interruptions

IEEE PES Innovative Smart Grid Technologies, Europe, 2014

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Risk assessment of smart energy transfer in distribution networks

IEEE PES Innovative Smart Grid Technologies, Europe, 2014

ABSTRACT Dynamic (or real-time) thermal rating (which utilizes actual weather conditions in order... more ABSTRACT Dynamic (or real-time) thermal rating (which utilizes actual weather conditions in order to more accurately model electro-thermal coordination behaviour of high voltage conductors) promises to play a vital role in the planning of energy transmission of future smart power systems. This paper investigates the adequacy impacts of real-time line thermal ratings (of different underground distribution network cabling systems), accounting for the following system risk issues: line losses and the risk of aging. The aim is to propose a new technique of assessing the reliability of distribution systems when cable-based line time varying thermal rating (TVTR) is implemented. This technique is illustrated through the reliability performance evaluation of a distribution system under a variety of cabling system configurations: XLPE; EPR and Solid paper insulated power cables; and the nine Standard Duct installation conditions. Concomitantly, the risk of aging the cable assets (RCAI) is evaluated in order to enhance planning decisions. Consequently, these probabilistic assessments reveal that oil pressure pipe-type cable ducting for an XLPE cable type has the lowest risk of aging the asset on the network; while Solid paper type cable installed in a fibre duct will experience the highest aging risk.

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Assessing optimal conductor utilization under N-1 overload security studies

2013 IEEE Grenoble Conference, 2013

ABSTRACT Elevated temperature operation (ETO) is as an attractive way of enabling better utilizat... more ABSTRACT Elevated temperature operation (ETO) is as an attractive way of enabling better utilization of existing transmission conductor assets especially during power system contingencies. However, due to the lack of Overhead Line conductor (OHLC) condition data, the present ETO ratings, short-term emergency (STE) and long-term emergency (LTE) ratings, are extremely conservative and inflexible. Furthermore, due to lack of sufficient historical operational data and algorithms, planners are unable to develop tools that enable increased and smarter utilization of the OHLC. The proliferation of modern real-time rating and other smart grid instrumentation allows for the use of historical data for planning purposes. On this basis, this paper presents how, in combination with OHL planning information, historical data can be utilized to develop improved operation guidance that accounts for the actual condition (ageing) of the OHLC. Therefore, it can be asserted that by knowing the OHLC condition, operators can flexibly make reliable cost effective decisions and thus be able to manage their OHL assets. Results are presented on a modified IEEE 24-bus RTS, implementing OHL properties into the analysis.

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Probabilistic assessment of impacts of real-time line ratings on distribution networks

2014 International Conference on Probabilistic Methods Applied to Power Systems (PMAPS), 2014

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Assessing the power transfer performance of a lattice tower overhead line system

IET Generation, Transmission & Distribution, 2013

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Evaluating opportunities for increasing power capacity of existing overhead line systems

IET Generation, Transmission & Distribution, 2011

Bookmarks Related papers MentionsView impact