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Full-Text Articles in Engineering

Three-Dimensional Velocity Distribution In Straight Smooth Channels Modeled By Modified Log-Law, Shu-Qing Yang, Muhammad Zain Bin Riaz, Muttucumaru Sivakumar, Keith Enever, Nadeeka Miguntanna Jan 2020

Three-Dimensional Velocity Distribution In Straight Smooth Channels Modeled By Modified Log-Law, Shu-Qing Yang, Muhammad Zain Bin Riaz, Muttucumaru Sivakumar, Keith Enever, Nadeeka Miguntanna

Faculty of Engineering and Information Sciences - Papers: Part B

Time-average velocity distribution in steady and uniform channel flows is important for fundamental research and practical application as it is always three-dimensional (3D), regardless of channel geometry. However, its determination has predominantly been carried out by using complex numerical software, even for the simplest geometry such as rectangular channels. The log-law was developed initially for circular pipe flows, where a single shear velocity is used to normalize the velocity (u+) and its distance (y+). Tracy and Lester found that the performance of the log-law can be extended to express velocity profiles in rectangular channels when the global shear velocities (gRS)0.5 …


A Noise Study Of The Psw Signature Family: Patching Drs With Uniform Distribution, Arnaud Sipasseuth, Thomas Plantard, Willy Susilo Jan 2020

A Noise Study Of The Psw Signature Family: Patching Drs With Uniform Distribution, Arnaud Sipasseuth, Thomas Plantard, Willy Susilo

Faculty of Engineering and Information Sciences - Papers: Part B

At PKC 2008, Plantard et al. published a theoretical framework for a lattice-based signature scheme, namely Plantard-Susilo-Win (PSW). Recently, after ten years, a new signature scheme dubbed the Diagonal Reduction Signature (DRS) scheme was presented in the National Institute of Standards and Technology (NIST) PQC Standardization as a concrete instantiation of the initial work. Unfortunately, the initial submission was challenged by Yu and Ducas using the structure that is present on the secret key noise. In this paper, we are proposing a new method to generate random noise in the DRS scheme to eliminate the aforementioned attack, and all subsequent …


Thermal Comfort Evaluation Of A Mixed-Mode Ventilated Office Building With Advanced Natural Ventilation And Underfloor Air Distribution Systems, Xiang Deng, Georgios Kokogiannakis, Zhenjun Ma, Paul Cooper Jan 2017

Thermal Comfort Evaluation Of A Mixed-Mode Ventilated Office Building With Advanced Natural Ventilation And Underfloor Air Distribution Systems, Xiang Deng, Georgios Kokogiannakis, Zhenjun Ma, Paul Cooper

Faculty of Engineering and Information Sciences - Papers: Part A

This study uses field monitoring and post occupancy evaluation (POE) surveys to investigate the indoor thermal comfort of an office building that is located in subtropical zone. The building is special as it combines advanced natural ventilation (ANV) strategies and underfloor air distribution (UFAD) systems. A comparison between a static thermal comfort model and a dynamic thermal comfort model is also conducted. The results show that the thermal comfort conditions in the case study building are satisfactory in summer while in winter there is evidence of thermal discomfort. For the case study building, the static thermal comfort model gives outputs …


Online Coordinated Voltage Control In Distribution Systems Subjected To Structural Changes And Dg Availability, Dothinka Ranamuka Rallage, Ashish P. Agalgaonkar, Kashem M. Muttaqi Jan 2016

Online Coordinated Voltage Control In Distribution Systems Subjected To Structural Changes And Dg Availability, Dothinka Ranamuka Rallage, Ashish P. Agalgaonkar, Kashem M. Muttaqi

Faculty of Engineering and Information Sciences - Papers: Part A

The responses of multiple DG units and voltage regulating devices such as tap changers and capacitor banks for correcting the voltage may lead to operational conflicts and oscillatory transients, where distribution systems are subjected to network reconfiguration and changes in availability of the DG units. Therefore, coordinated voltage control is required to minimize control interactions while accounting for the impact of structural changes associated with the network. This paper proposes a strategy for coordinating the operation of multiple voltage regulating devices and DG units in medium voltage (MV) distribution systems, under structural changes and DG availability, for effective voltage control. …


A Review Of Protection Systems For Distribution Networks Embedded With Renewable Generation, Joel Kennedy, Philip Ciufo, Ashish P. Agalgaonkar Jan 2016

A Review Of Protection Systems For Distribution Networks Embedded With Renewable Generation, Joel Kennedy, Philip Ciufo, Ashish P. Agalgaonkar

Faculty of Engineering and Information Sciences - Papers: Part A

The rapid growth of grid-connected embedded generation is changing the operational characteristics of power distribution networks. Amongst a range of issues being reported in the research, the effect of these changes on so-called 'traditional protection systems' has not gone without attention. Looking to the future, the possibility of microgrid systems and deliberate islanding of sections of the network will require highly flexible distribution management systems and a re-design of protection strategies. This paper explores the envisaged protection issues concerned with large penetrations of embedded generation in distribution networks extending into auto-reclosure and protection device coordination. A critical review of recently …


Power Sharing Among Multiple Solar Photovoltaic (Pv) Systems In A Radial Distribution Feeder, Brian K. Perera, Philip Ciufo Apr 2015

Power Sharing Among Multiple Solar Photovoltaic (Pv) Systems In A Radial Distribution Feeder, Brian K. Perera, Philip Ciufo

Dr Philip Ciufo

With an increasing penetration of solar photovoltaic (PV) systems, power distribution grids are becoming more susceptible to network voltage rise. As per applicable standards for grid-integrated PV systems, a PV system must be automatically disconnected from the grid when the terminal voltage of the PV system exceeds a defined maximum voltage. With this directive, in certain situations, PV systems connected at nodes at which the voltage sensitivity is high, may be disconnected from the grid while PV systems connected at less sensitive nodes are continuing to operate. In such a situation, owners whose PV systems are connected at nodes at …


A Sensitivity Analysis Toolkit For The Simplification Of Mv Distribution Network Voltage Management, Fabian Tamp, Philip Ciufo Apr 2015

A Sensitivity Analysis Toolkit For The Simplification Of Mv Distribution Network Voltage Management, Fabian Tamp, Philip Ciufo

Dr Philip Ciufo

As distribution networks become increasingly variable and generation becomes increasingly decentralised, voltage standards are becoming more liable to violation. Accordingly, intelligent voltage management strategies are required to enable standards compliance without unduly increasing network maintenance or infrastructure costs. The relationship between network power and voltages, however, is complex, non-linear and interdependent, and thus is difficult to conceptualise and use for decision-making and control purposes. This paper introduces a software toolkit that simplifies the development of voltage management strategies by the application of sensitivity analysis. Sensitivity analysis reduces complex network relationships to simple linear equations, and thus enables easy and comprehensive …


Over-Voltage Mitigation Within Distribution Networks With A High Renewable Distributed Generation Penetration, Joel Kennedy, Philip Ciufo, Ashish Agalgaonkar Apr 2015

Over-Voltage Mitigation Within Distribution Networks With A High Renewable Distributed Generation Penetration, Joel Kennedy, Philip Ciufo, Ashish Agalgaonkar

Dr Philip Ciufo

The rapid growth of grid-connected distributed generation has increased the likelihood of over-voltage occurrences in distribution networks. In recent times, much research has taken place in order to develop a control strategy to mitigate the voltage rise problem. However, most of the published strategies require re-tuning when additional resources are connected, or have a strong dependence on network parameters, such as fault level. This paper proposes a novel over-voltage mitigation scheme that has many advantages not observed in literature. Firstly, the control scheme can integrate with an existing feeder in a plug-and-play fashion. No prior analysis is necessary to configure …


Simulink Model For Examining Dynamic Interactions Involving Electro-Mechanical Oscillations In Distribution Systems, Dothinka Ranamuka Rallage, Ashish P. Agalgaonkar, Kashem M. Muttaqi Jan 2015

Simulink Model For Examining Dynamic Interactions Involving Electro-Mechanical Oscillations In Distribution Systems, Dothinka Ranamuka Rallage, Ashish P. Agalgaonkar, Kashem M. Muttaqi

Faculty of Engineering and Information Sciences - Papers: Part A

In Australian medium voltage (MV) distribution networks, the majority of embedded local generation (LG) uses synchronous machine based technology. LG units with a synchronous generator can easily be dispatched and controlled to provide or absorb reactive power and thereby locally supporting the system voltage and increasing the voltage stability margin. The fast response from a synchronous machine based LG unit exciter will ensure fast voltage recovery. This will significantly improve the transient voltage stability. Also, the synchronous machine based LG units can provide inertial support to the system. Furthermore, some of these LG technologies work as standby power supplies all …


Application Of Saturated Core Fault Current Limiters To Interconnected Distribution Networks, Sasareka Gunawardana Mudalige, Sarath Perera, Jeffrey W. Moscrop Jan 2015

Application Of Saturated Core Fault Current Limiters To Interconnected Distribution Networks, Sasareka Gunawardana Mudalige, Sarath Perera, Jeffrey W. Moscrop

Faculty of Engineering and Information Sciences - Papers: Part A

There is an increasing need for electricity utilities to limit fault levels in critical locations in power systems so that existing switchgear can continue to function as expected. This is particularly true in electrical distribution systems, where the increased penetration of renewable and decentralised generation is forcing the network to be highly interconnected in order to allow for higher integration capacity and reliable operation. Consequently, the short-circuit currents in distribution systems have increased significantly. In this background, application of fault current limiting devices is one of the solutions that is being considered by the Distribution Network Service Providers (DNSPs). A …


Attenuation And Propagation Of Voltage Unbalance In Radial Distribution Networks, Devinda Perera, Philip Ciufo, Lasantha G. Meegahapola, Sarath Perera Jan 2015

Attenuation And Propagation Of Voltage Unbalance In Radial Distribution Networks, Devinda Perera, Philip Ciufo, Lasantha G. Meegahapola, Sarath Perera

Faculty of Engineering and Information Sciences - Papers: Part A

Recently published International Electrotechnical Committee (IEC) technical reports IEC 61000-3-13 provides detailed methodologies for managing voltage unbalance (VU) in electric power systems. A key aspect in the VU emission allocation process is the estimation of VU propagation in different parts of the network. Although the VU propagation from upstream networks to downstream networks is adequately addressed, the attenuation of VU when propagating from downstream to upstream networks at the same voltage level has not been properly taken into account in the aforementioned methodologies. Furthermore, mains connected three-phase induction motors are known to attenuate VU, and there is no methodology currently …


Optimal Distribution Control Of Non‐Linear Tire Force Of Electric Vehicles With In‐Wheel Motors, Boyuan Li, Haiping Du, Weihua Li Jan 2015

Optimal Distribution Control Of Non‐Linear Tire Force Of Electric Vehicles With In‐Wheel Motors, Boyuan Li, Haiping Du, Weihua Li

Faculty of Engineering and Information Sciences - Papers: Part A

An over-actuated control system has the advantage of being able to use redundant actuators to reconfigure the control system and it can realize fault tolerant control. In order to achieve improved vehicle stability and handling performance for electric vehicles with in-wheel steering and driving motors, the control of the vehicle body slip angle and yaw rate is actually an over-actuated control problem. To obtain the optimal solution for this control problem, this study proposes a two-level tire force distribution control method, where the upper level controller calculates the desired lateral and longitudinal forces generated by friction on the tire of …


The Optimisation Of The Secondary Cooling Water Distribution With Improved Genetic Algorithm In Continuous Casting Of Steels, Yu-Chun Zhai, Ying Li, Beiyue Ma, C Yan, Zhengyi Jiang Jan 2015

The Optimisation Of The Secondary Cooling Water Distribution With Improved Genetic Algorithm In Continuous Casting Of Steels, Yu-Chun Zhai, Ying Li, Beiyue Ma, C Yan, Zhengyi Jiang

Faculty of Engineering and Information Sciences - Papers: Part A

An improved genetic algorithm is presented for the water consumption of the secondary cooling zone based on the heat transfer model of the off-line bloom caster. This study is to control the existing cooling systems and the steel casting practises in order to produce steel with best possible quality. The fitness function of improved genetic algorithm is founded according to the metallurgical criteria. This algorithm coupled with heat transfer model and metallurgical criteria, added dynamic coding method and self-adapting mutation on the original genetic algorithm can increase water distribution adaptively and improve the process efficiency. The simulation results of T91 …


Over-Voltage Mitigation Within Distribution Networks With A High Renewable Distributed Generation Penetration, Joel Kennedy, Philip Ciufo, Ashish Agalgaonkar Jan 2014

Over-Voltage Mitigation Within Distribution Networks With A High Renewable Distributed Generation Penetration, Joel Kennedy, Philip Ciufo, Ashish Agalgaonkar

Faculty of Engineering and Information Sciences - Papers: Part A

The rapid growth of grid-connected distributed generation has increased the likelihood of over-voltage occurrences in distribution networks. In recent times, much research has taken place in order to develop a control strategy to mitigate the voltage rise problem. However, most of the published strategies require re-tuning when additional resources are connected, or have a strong dependence on network parameters, such as fault level. This paper proposes a novel over-voltage mitigation scheme that has many advantages not observed in literature. Firstly, the control scheme can integrate with an existing feeder in a plug-and-play fashion. No prior analysis is necessary to configure …


Voltage Unbalance Emission Allocation Using Constrained Bus Voltage Method In Radial Distribution Networks, Devinda Perera, Philip Ciufo, Sarath Perera, Lasantha Meegahapola Jan 2014

Voltage Unbalance Emission Allocation Using Constrained Bus Voltage Method In Radial Distribution Networks, Devinda Perera, Philip Ciufo, Sarath Perera, Lasantha Meegahapola

Faculty of Engineering and Information Sciences - Papers: Part A

The International Electrotechnical Committee Technical Report IEC 61000-3-13 is focused on the coordination of voltage unbalance (VU) in power systems by prescribing a methodology to determine individual VU emission allocation limits to installations. This paper provides an alternative VU emission allocation process to that of the IEC Technical Report, which is based on the concept of constrained bus voltage (CBV) method. The proposed methodology can be used in relation to radial distribution networks with symmetrical distribution lines. Several application examples of the proposed methodology are presented. It is shown that the proposed methodology is superior in comparison to the VU …


An Algebraic Approach For Determination Of Dg Parameters To Support Voltage Profiles In Radial Distribution Networks, Kashem M. Muttaqi, An D. T Le, Michael Negnevitsky, Gerard Ledwich Jan 2014

An Algebraic Approach For Determination Of Dg Parameters To Support Voltage Profiles In Radial Distribution Networks, Kashem M. Muttaqi, An D. T Le, Michael Negnevitsky, Gerard Ledwich

Faculty of Engineering and Information Sciences - Papers: Part A

Rapidly increasing electricity demands and capacity shortage of transmission and distribution facilities are the main driving forces for the growth of Distributed Generation (DG) integration in power grids. One of the reasons for choosing a DG is its ability to support voltage in a distribution system. Selection of effective DG characteristics and DG parameters is a significant concern of distribution system planners to obtain maximum potential benefits from the DG unit. This paper addresses the issue of improving the network voltage profile in distribution systems by installing a DG of the most suitable size, at a suitable location. An analytical …


Distribution Expansion Planning Considering Reliability And Security Of Energy Using Modified Pso (Particle Swarm Optimization) Algorithm, Jamshid Aghaei, Kashem M. Muttaqi, Ali Azizivahed, Mohsen Gitizadeh Jan 2014

Distribution Expansion Planning Considering Reliability And Security Of Energy Using Modified Pso (Particle Swarm Optimization) Algorithm, Jamshid Aghaei, Kashem M. Muttaqi, Ali Azizivahed, Mohsen Gitizadeh

Faculty of Engineering and Information Sciences - Papers: Part A

Distribution feeders and substations need to provide additional capacity to serve the growing electrical demand of customers without compromising the reliability of the electrical networks. Also, more control devices, such as DG (Distributed Generation) units are being integrated into distribution feeders. Distribution networks were not planned to host these intermittent generation units before construction of the systems. Therefore, additional distribution facilities are needed to be planned and prepared for the future growth of the electrical demand as well as the increase of network hosting capacity by DG units. This paper presents a multiobjective optimization algorithm for the MDEP (Multi-Stage Distribution …


Control Issues Of Distribution System Automation In Smart Grids, Kashem M. Muttaqi, Ali Esmaeel Nezhad, Jamshid Aghaei, Velappa Ganapathy Jan 2014

Control Issues Of Distribution System Automation In Smart Grids, Kashem M. Muttaqi, Ali Esmaeel Nezhad, Jamshid Aghaei, Velappa Ganapathy

Faculty of Engineering and Information Sciences - Papers: Part A

In recent years, the world has been exposed to many developments in different areas esp. computer technology, resulting in computers with high power of processing to be built. Among these devices, intelligent electronic devices (IEDs) have the capability to process considerable volume of data at high speed. Since, real-time data processing is vital in distribution networks as the largest users during their operation, IEDs would be applicable in such systems. In addition to IEDS, communication systems have improved during recent decades, providing the desired conditions for a concept known as distribution system automation (DSA) which has been discussed in this …


Characterisation Of Flicker Emission And Propagation In Distribution Networks With Bi-Directional Power Flows, D Perera, L Meegahapola, S Perera, P Ciufo Jan 2014

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

Faculty of Engineering and Information Sciences - Papers: Part A

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. …


Molecular Weight Distribution Of Network Strands In Double Network Hydrogels Estimated By Mechanical Testing, Hai Xin, Hugh Ralph Brown, Geoffrey M. Spinks Jan 2014

Molecular Weight Distribution Of Network Strands In Double Network Hydrogels Estimated By Mechanical Testing, Hai Xin, Hugh Ralph Brown, Geoffrey M. Spinks

Faculty of Engineering and Information Sciences - Papers: Part A

The remarkably high toughness of double network (DN) hydrogels is related to the energy dissipation that occurs due to the scission of network strands in the most tightly crosslinked of its two interpenetrating networks. The loading curve during tensile testing of DN hydrogels usually takes a complex shape and sometimes shows yielding. Wang and Hong recently proposed a model [1] based on the successive scission of the shortest remaining elastically active strands during tensile loading that predicts the shape of the loading curve of one DN hydrogel reasonably well. In the present study, the model was modified slightly and applied …


A Sensitivity Analysis Toolkit For The Simplification Of Mv Distribution Network Voltage Management, Fabian Tamp, Philip Ciufo Jan 2014

A Sensitivity Analysis Toolkit For The Simplification Of Mv Distribution Network Voltage Management, Fabian Tamp, Philip Ciufo

Faculty of Engineering and Information Sciences - Papers: Part A

As distribution networks become increasingly variable and generation becomes increasingly decentralised, voltage standards are becoming more liable to violation. Accordingly, intelligent voltage management strategies are required to enable standards compliance without unduly increasing network maintenance or infrastructure costs. The relationship between network power and voltages, however, is complex, non-linear and interdependent, and thus is difficult to conceptualise and use for decision-making and control purposes. This paper introduces a software toolkit that simplifies the development of voltage management strategies by the application of sensitivity analysis. Sensitivity analysis reduces complex network relationships to simple linear equations, and thus enables easy and comprehensive …


An Approach For Online Assessment Of Rooftop Solar Pv Impacts On Low-Voltage Distribution Networks, Md Jan-E- Alam, Kashem Muttaqi, Darmawan Sutanto Jan 2014

An Approach For Online Assessment Of Rooftop Solar Pv Impacts On Low-Voltage Distribution Networks, Md Jan-E- Alam, Kashem Muttaqi, Darmawan Sutanto

Faculty of Engineering and Information Sciences - Papers: Part A

Assumption-based offline analysis tools may not be able to provide sufficient and accurate information for the corrective decision making to mitigate solar photovoltaic (PV) impacts in the future distribution grids. This is mainly due to the increasing penetration level of intermittent power generation resources and also the fluctuating behavior of consumer demand. Online assessment tools can assist to manage PV impacts and aid to mitigate those on a real-time basis. This paper proposes an approach for online assessment of rooftop PV impacts on low-voltage (LV) networks using real-time network data. A variable-width sliding window will be used to provide the …


Online Voltage Control In Distribution Systems With Multiple Voltage Regulating Devices, Dothinka Ranamuka Rallage, Ashish Agalgaonkar, Kashem Muttaqi Jan 2014

Online Voltage Control In Distribution Systems With Multiple Voltage Regulating Devices, Dothinka Ranamuka Rallage, Ashish Agalgaonkar, Kashem Muttaqi

Faculty of Engineering and Information Sciences - Papers: Part A

Voltage regulation in distribution systems is typically performed with the aid of multiple voltage regulating devices, such as on-load tap changer and step voltage regulators. These devices are conventionally tuned and locally coordinated using Volt/VAR optimization strategies in accordance with the time-graded operation. However, in case of distribution systems with distributed generation (DG), there could be a possibility of simultaneous responses of DG and multiple voltage regulators for correcting the target bus voltage, thereby resulting in operational conflicts. This paper proposes an online voltage control strategy for a realistic distribution system containing a synchronous machine-based renewable DG unit and other …


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. …


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 …


Velocity Distribution In Non-Uniform/Unsteady Flows And The Validity Of Log Law, Ishraq Alfadhli, Shu-Qing Yang, Muttucumaru Sivakumar Dec 2013

Velocity Distribution In Non-Uniform/Unsteady Flows And The Validity Of Log Law, Ishraq Alfadhli, Shu-Qing Yang, Muttucumaru Sivakumar

Ishraq Hamdan Alfadhli

This study investigates the longitudinal velocity profiles in steady and unsteady non-uniform open channel flows by analyzing the data available in the literature. It was found that for steady/unsteady flow in the Log law is applicable only in the inner region where y/hg


Distribution Of Reynolds Shear Stress In Steady And Unsteady Flows, Ishraq Alfadhli, Shu-Qing Yang, Muttucumaru Sivakumar Dec 2013

Distribution Of Reynolds Shear Stress In Steady And Unsteady Flows, Ishraq Alfadhli, Shu-Qing Yang, Muttucumaru Sivakumar

Ishraq Hamdan Alfadhli

This study investigates the Reynolds shear stress distribution in steady and unsteady non-uniform flows. Specifically, it deals with how to express the deviation of this turbulence characteristic from that of uniform flow line; it is found that flow acceleration can well represent the deviation of Reynolds shear stress from its standard linear distribution. By connecting the flow acceleration with Reynolds shear stress, the study demonstrates empirically that the linear distrubiton of Reynolds shear stress can be observed when the flow acceleration is zero; the concave distribution of Reynolds shear stress can be observed when the flow acceleration is negative or …


A Multiagent Approach For Decentralized Voltage Regulation In Power Distribution Networks Within Dgs, Fenghui Ren, Minjie Zhang, Danny Sutanto Oct 2013

A Multiagent Approach For Decentralized Voltage Regulation In Power Distribution Networks Within Dgs, Fenghui Ren, Minjie Zhang, Danny Sutanto

Dr Fenghui Ren

Voltage regulation (VR) is a procedure to keep voltages in a distribution network (DN) within normal limits. Conven- tionally, a voltage regulator can read voltage levels from pre- dened measures, and regulate the voltages. However, due to lacking of a distributed generator's (DG) information, the unexpected electricity from a DG will mislead readings on voltages levels, so as to disturb the VR in a DN. Adjust- ing a DG's reactive power output is an alternative way for VR. However, because of limited penetration levels, DGs need to collaborate with other devices in order to provide an eective voltage regulation. Therefore, …


A Multi-Agent Solution To Distribution System Management By Considering Distributed Generators, Fenghui Ren, Minjie Zhang, Darmawan Sutanto Oct 2013

A Multi-Agent Solution To Distribution System Management By Considering Distributed Generators, Fenghui Ren, Minjie Zhang, Darmawan Sutanto

Dr Fenghui Ren

A traditional distribution network carries electricity from a central power resource to consumers, and the power dispatch is controlled centrally. Distributed generators (DGs) emerge as an alternative power resource to distribution networks at a smaller and distributed scale, which will bring benefits such as reduced voltage drop and loss. However, because most of high penetration DGs are not utility owned and characterized by high degree of uncertainty such as solar and wind, the distribution network may perform differently from the conventionally expected behaviors. How to dynamically and efficiently manage the power dispatch in a distribution network to balance the supply …