Open Access. Powered by Scholars. Published by Universities.®

Social and Behavioral Sciences Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 9 of 9

Full-Text Articles in Social and Behavioral Sciences

Impact Of Wind Generator Control Strategies On Flicker Emission In Distribution Networks, Lasantha Meegahapola, Sarath Perera Dec 2013

Impact Of Wind Generator Control Strategies On Flicker Emission In Distribution Networks, Lasantha Meegahapola, Sarath Perera

Dr Lasantha G Meegahapola

Renewable power generators are increasingly being integrated to electricity networks to achieve future renewable energy targets in power generation. In particular, wind power generation has already reported substantial penetration levels in electricity networks. Traditionally, flicker phenomenon is considered to be one of the power quality issues in power distribution networks due to fluctuating consumer loads connected to the network. Large-scale integration of wind power generators may create significant voltage fluctuations in distribution feeders due to stochastic and intermittent nature of the wind resources. This study aims to investigate and characterize the flicker emission under different control strategies for DFIG based …


Characterisation Of Flicker Emission And Propagation In Distribution Networks With Bi-Directional Power Flows, D Perera, L Meegahapola, S Perera, P Ciufo Dec 2013

Characterisation Of Flicker Emission And Propagation In Distribution Networks With Bi-Directional Power Flows, D Perera, L Meegahapola, S Perera, P Ciufo

Dr Lasantha G Meegahapola

With the increasing penetration levels of intermittent and fluctuating energy sources such as wind generating systems in the electricity grid, resulting voltage fluctuations and flicker can be expected to become an important power quality considerations. Due to significant bidirectional power flows resulting from large renewable power generation systems connected to downstream, voltage fluctuations may propagate from downstream to upstream. The work presented in this paper investigates and characterises flicker emission and propagation resulting from fluctuating generating sources connected to a distribution network. Mathematical models are developed for flicker emission under different generator control strategies and flicker propagation to upstream network. …


Comparative Analysis Of Dynamic Line Rating Models And Feasibility To Minimise Energy Losses In Wind Rich Power Networks, Mathew Simms, Lasantha Meegahapola Dec 2013

Comparative Analysis Of Dynamic Line Rating Models And Feasibility To Minimise Energy Losses In Wind Rich Power Networks, Mathew Simms, Lasantha Meegahapola

Dr Lasantha G Meegahapola

Wind power generation has indicated an exponential increase during last two decades and existing transmission network infrastructure is increasingly becoming inadequate to transmit remotely generated wind power to load centres in the network. The dynamic line rating (DLR) is one of the viable solutions to improve the transmission line ampacity during high wind penetration without investing on an additional transmission network. The main objective of this study is to identify the basic differences between two main line rating standards, since transmission network service providers (TNSPs) heavily depend on these two standards when developing their line rating models. Therefore, a parameter …


Flicker Mitigation Strategy For Dfigs During Variable Wind Conditions, Lasantha Meegahapola, Brendan Fox, Damian Flynn Dec 2013

Flicker Mitigation Strategy For Dfigs During Variable Wind Conditions, Lasantha Meegahapola, Brendan Fox, Damian Flynn

Dr Lasantha G Meegahapola

This paper presents a flicker mitigation scheme for the doubly-fed induction generator (DFIG) during variable wind conditions. The flicker mitigation strategy was developed based on the distribution line X/R ratio and the active power deviation from the average active power during variable wind conditions. Flicker emission was analyzed using a flicker meter based on the IEC standards. Both short-term and long-term flicker severities were analyzed during the time period of study. The flicker mitigation strategy was evaluated under different system conditions such as X/R ratio, distribution line length, shortcircuit capacity (SCC), and wind variability. It is shown that the proposed …


Multi-Objective Reactive Power Support From Wind Farms For Network Performance Enhancement, Lasantha Meegahapola, Brendan Fox, Tim Littler, Damian Flynn Dec 2013

Multi-Objective Reactive Power Support From Wind Farms For Network Performance Enhancement, Lasantha Meegahapola, Brendan Fox, Tim Littler, Damian Flynn

Dr Lasantha G Meegahapola

This paper examines the ability of the doubly fed induction generator (DFIG) to deliver multiple reactive power objectives during variable wind conditions. The reactive power requirement is decomposed based on various control objectives (e.g. power factor control, voltage control, loss minimisation, and flicker mitigation) defined around different time frames (i.e. seconds, minutes, and hourly), and the control reference is generated by aggregating the individual reactive power requirement for each control strategy. A novel coordinated controller is implemented for the rotor-side converter and the grid-side converter considering their capability curves and illustrating that it can effectively utilise the aggregated DFIG reactive …


Voltage Security Constrained Reactive Power Optimization Incorporating Wind Generation, L G. Meegahapola, E Vittal, A Keane, D Flynn Dec 2013

Voltage Security Constrained Reactive Power Optimization Incorporating Wind Generation, L G. Meegahapola, E Vittal, A Keane, D Flynn

Dr Lasantha G Meegahapola

This paper presents a comparative analysis between conventional optimal power flow (OPF) and voltage constrained OPF strategies with wind generation. The study has been performed using the New England 39 bus system with 12 doublyfed induction generator (DFIG) based wind farms installed across the network. A voltage security assessment is carried out to determine the critical wind farms for voltage stability enhancement. The power losses and individual wind farm reactive power generation have been compared with and without voltage stability constraints imposed on the OPF simulation. It is shown that voltage constrained OPF leads to much greater active power losses …


Dynamic Characteristics Of A Hybrid Microgrid With Inverter And Non- Inverter Interfaced Renewable Energy Sources: A Case Study, A V. Jayawardena, L G. Meegahapola, S Perera, D A. Robinson Dec 2013

Dynamic Characteristics Of A Hybrid Microgrid With Inverter And Non- Inverter Interfaced Renewable Energy Sources: A Case Study, A V. Jayawardena, L G. Meegahapola, S Perera, D A. Robinson

Dr Lasantha G Meegahapola

Microgrids are becoming important constituents of electric power distribution networks. Microgrids are typically comprised of both inverter interfaced (e.g. double-fed induction generator (DFIG), solar-photovoltaic (PV) system) and non-inverter interfaced (e.g. synchronous generator) renewable energy generators (REGs), hence their dynamic characteristics are significantly different from the conventional grids comprised of centralised synchronous generators. Different inherent characteristics of REGs, power dispatch levels, relative REG capacities, and external grid characteristics are some of the important features of significant interest in relation to microgrid dynamic behaviour. For this study a microgrid model was developed in DIgSILENT Power Factory based on the IEEE-13 bus system …


Capability Curve Based Enhanced Reactive Power Control Strategy For Stability Enhancement And Network Voltage Management, Lasantha Meegahapola, Tim Littler, Sarath Perera Dec 2013

Capability Curve Based Enhanced Reactive Power Control Strategy For Stability Enhancement And Network Voltage Management, Lasantha Meegahapola, Tim Littler, Sarath Perera

Dr Lasantha G Meegahapola

Reactive power has become a vital resource in modern electricity networks due to increased penetration of distributed generation. This paper examines the extended reactive power capability of DFIGs to improve network stability and capability to manage network voltage profile during transient faults and dynamic operating conditions. A coordinated reactive power controller is designed by considering the reactive power capabilities of the rotor-side converter (RSC) and the grid-side converter (GSC) of the DFIG in order to maximise the reactive power support from DFIGs. The study has illustrated that, a significant reactive power contribution can be obtained from partially loaded DFIG wind …


Flicker Propagation Analysis In Distribution Networks With Embedded Generation, D Perera, L Meegahapola, S Perera, P Ciufo Dec 2013

Flicker Propagation Analysis In Distribution Networks With Embedded Generation, D Perera, L Meegahapola, S Perera, P Ciufo

Dr Lasantha G Meegahapola

Embedded generators such as wind generators can produce observable voltage fluctuations during variable wind conditions hence flicker. The flicker produced by such intermittent and fluctuating generating sources can propagate to other parts of the distribution network while creating power quality issues in distribution feeders. This study presents a flicker emission analysis for a doubly-fed induction generator (DFIG) based wind farm and investigate the pertinent factors which influence flicker propagation and attenuation in distribution feeders. Study has shown that voltage fluctuations are significantly influenced by the attenuation characteristics of various load types (i.e. constant power, impedance and current loads) connected to …