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Full-Text Articles in Engineering

Novel Modulation And Control Strategy For Five-Level Anpc Converter With Unbalanced Dc Voltage Applied To A Single-Phase Grid Connected Pv System, Hamid R. Teymour, Danny Sutanto, Kashem M. Muttaqi, Phil Ciufo Apr 2015

Novel Modulation And Control Strategy For Five-Level Anpc Converter With Unbalanced Dc Voltage Applied To A Single-Phase Grid Connected Pv System, Hamid R. Teymour, Danny Sutanto, Kashem M. Muttaqi, Phil Ciufo

Dr Philip Ciufo

This paper proposes a new control strategy and a novel modulation technique for a grid-connected photo-voltaic (PV) system using a single-phase five-level flying capacitor (FC) based active-neutral-point-clamped (ANPC) converter. The proposed modulator can control the FC voltage to follow the requested reference value and simultaneously generate the required ac output voltage regardless of the values of the dc capacitor voltages of the converter. By implementing this method, smaller values of dc-link and flying capacitors can be used even in applications that could experience ripple or transient in the capacitors voltage. In the grid-connected single-phase five-level ANPC, where the capacitors can …


A Review Of Recent Investigations On Voltage Unbalance Management: Further Contributions To Improvement Of Iec/Tr 61000-3-13:2008, Jayatunga Vitharanage Upuli Priyadarshani Jayatunga, Sarath Perera, Philip Ciufo, Ashish Agalgaonkar Apr 2015

A Review Of Recent Investigations On Voltage Unbalance Management: Further Contributions To Improvement Of Iec/Tr 61000-3-13:2008, Jayatunga Vitharanage Upuli Priyadarshani Jayatunga, Sarath Perera, Philip Ciufo, Ashish Agalgaonkar

Dr Philip Ciufo

Voltage unbalance (VU) management in power systems essentially involves two major aspects: VU emission allocation at the pre-connection stage and compliance assessment at the post-connection stage of installations. This is a summary and a review paper on the recent investigations completed in relation to VU emission assessment techniques which provide further contributions to the improvement of IEC Technical Report IEC/TR61000-3-13:2008. Generalised approaches developed for the classification of different sources of unbalance at the point of evaluation (covering both radial and interconnected networks) and the evaluation of their individual contributions giving emphasis to the discrimination between customer and network responsibility on …


Performance Of Adjustable Speed Drives Subject To Regular Voltage Fluctuations, Kun Zhao, Philip Ciufo, Sarath Perera Apr 2015

Performance Of Adjustable Speed Drives Subject To Regular Voltage Fluctuations, Kun Zhao, Philip Ciufo, Sarath Perera

Dr Philip Ciufo

The impact of power quality disturbances on customer equipment has been a topic of interest to equipment manufacturers, electricity utilities, customers and to those involved in the development of electromagnetic compatibility standards. Recently, a new interest has developed in the possible impact of voltage fluctuations on customer equipment because of suggestions to relax voltage fluctuation limits and hence the flicker limits in power systems. With a view to contribute to this understanding, this paper investigates the performance of an adjustable speed drive (ASD) when subjected to sinusoidal regular voltage fluctuations. When the ASD is operating in open loop mode, the …


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 …


Voltage Unbalance Emission Assessment: Sources Of Contribution And Their Ranking, U Jayatunga, Sarath Perera, P Ciufo, A P. Agalgaonkar Apr 2015

Voltage Unbalance Emission Assessment: Sources Of Contribution And Their Ranking, U Jayatunga, Sarath Perera, P Ciufo, A P. Agalgaonkar

Dr Philip Ciufo

etermining sources of voltage unbalance (VU) and quantifying their individual contributions in an interconnected network is a complex task due to multiple interactions that take place between them. Post-connection VU emission assessment techniques in relation to customer installations are important not only in compliance assessment according to IEC/TR 61000-3- 13:2008 Limits - Assessment of emission limits for the connection of unbalanced installations to MV, HV and EHV power systems, but also in determining the various emission contributors in the power system being considered. This paper presents a case study on the application of a recently developed post-connection VU emission assessment …


Point Of Common Coupling (Pcc) Voltage Control Of A Grid-Connected Solar Photovoltaic (Pv) System, Brian K. Perera, Philip Ciufo, Sarath Perera Apr 2015

Point Of Common Coupling (Pcc) Voltage Control Of A Grid-Connected Solar Photovoltaic (Pv) System, Brian K. Perera, Philip Ciufo, Sarath Perera

Dr Philip Ciufo

In future low voltage grids, with multiple inverter interfaced sources connected, voltage regulation may become a necessary task. The potential exists for inverter interfaced sources to be deployed to regulate the voltage at the point of common coupling (PCC) of each inverter interfaced sources. The PCC voltage regulation is attainable with inverter interfaced sources by dynamically controlling the amount of reactive power injected to the power distribution grid by individual systems. In the current research, a closed-loop controller is proposed to regulate the PCC voltage of a solar photovoltaic (PV) system that is connected to a single-phase power distribution feeder …


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 …


Improving Low Voltage Ride-Through Using Super Capacitor At The Dc Link Of Doubly-Fed Induction Generator Based Wind Turbine, Ahmed M. Haidar, Mehrdad Tarafdar Hagh, Kashem M. Muttaqi Jan 2015

Improving Low Voltage Ride-Through Using Super Capacitor At The Dc Link Of Doubly-Fed Induction Generator Based Wind Turbine, Ahmed M. Haidar, Mehrdad Tarafdar Hagh, Kashem M. Muttaqi

Faculty of Engineering and Information Sciences - Papers: Part A

This paper presents a simple methodology to improve the low voltage ride-through (LVRT) capability of Doubly Fed Induction Generator (DFIG) based wind turbines in order to ride through higher voltage sags and durations. The proposed method is based on selection of an appropriate value for DC side super capacitor (SC) in such a way that it could help wind turbine for LVRT without any need to crowbar protection. The operation of SC based wind turbine in normal and fault conditions is simulated using MATLAB/SIMULINK. The simulation results show that the proposed method can be used effectively for LVRT improvement and …


Characteristics Of Power Quality Disturbances In Australia: Voltage Dips At Low-Voltage Sites, Sean T. Elphick, Victor W. Smith, Victor J. Gosbell, Sarath Perera, Philip Ciufo, Gerrard M. Drury Jan 2015

Characteristics Of Power Quality Disturbances In Australia: Voltage Dips At Low-Voltage Sites, Sean T. Elphick, Victor W. Smith, Victor J. Gosbell, Sarath Perera, Philip Ciufo, Gerrard M. Drury

Faculty of Engineering and Information Sciences - Papers: Part A

Voltage dips are considered to be one of the costliest of all power quality disturbances due to their disruption of industrial and commercial operations. The ability to characterise the voltage dip performance of distribution networks has many benefits for industry. There is considerable potential for industry to make large economic gains if voltage dip behaviour can be better understood and planned for. To put strategies in place to deal with voltage dips, there is a need for extensive data collection and analysis so that correct planning decisions can be made. This study details the characteristics of voltage dip data which …


Voltage Sag Compensation Of Point Of Common Coupling For Low Voltage Ride-Through Enhancment Of Inverter Interfaced Dg Using Bridge Type Fcl, Seyed Behzad Naderi, Michael Negnevitsky, Amin Jalilian, Mehrdad Tarafdar Hagh, Kashem M. Muttaqi Jan 2015

Voltage Sag Compensation Of Point Of Common Coupling For Low Voltage Ride-Through Enhancment Of Inverter Interfaced Dg Using Bridge Type Fcl, Seyed Behzad Naderi, Michael Negnevitsky, Amin Jalilian, Mehrdad Tarafdar Hagh, Kashem M. Muttaqi

Faculty of Engineering and Information Sciences - Papers: Part A

Fully converter wind turbines and solar power utilise an inverter to connect to grid. The inverters are vulnerable to voltage sag in their terminal due to its damaging effect on semiconductor self-Turnoff switches. In this paper, a bridge-Type fault current limiter (B-FCL) is proposed for low voltage ride-Through (LVRT) of the inverters during different types of fault with simple control system. The proposed B-FCL is capable to compensate the voltage sag in point of common coupling (PCC) and makes a safe condition not only for the inverter but also for any equipment which has been connected to the PCC in …


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 …


Modeling And Current Control Strategy For A Medium-Voltage Cascaded Multilevel Statcom With Lcl Filter, Xuehua Zhao, Liping Shi, Libing Chen, Zhenglong Xia, A R. Bendre Jan 2015

Modeling And Current Control Strategy For A Medium-Voltage Cascaded Multilevel Statcom With Lcl Filter, Xuehua Zhao, Liping Shi, Libing Chen, Zhenglong Xia, A R. Bendre

Faculty of Engineering and Information Sciences - Papers: Part A

The Static Synchronous Compensator (STATCOM a.k.a. SVG) is widely used to regulate dynamic reactive power and to solve dynamic voltage stability problems. Modeling shows that a cascaded STATCOM, which is composed of several cascaded H-bridges, not only has strong coupling characteristics when an LCL filter is added but it is also a non-linear, multivariable system. Therefore, its practical design and application are difficult to mplement. In this paper an internal decoupling control algorithm is introduced to provide independent control of the active and reactive currents. Decoupling control algorithms are proposed, and models and simulation of the decoupling are provided. We …


A New Approach For Classification And Characterization Of Voltage Dips And Swells Using 3d Polarization Ellipse Parameters, Mollah R. Alam, Kashem M. Muttaqi, Abdesselam Bouzerdoum Jan 2015

A New Approach For Classification And Characterization Of Voltage Dips And Swells Using 3d Polarization Ellipse Parameters, Mollah R. Alam, Kashem M. Muttaqi, Abdesselam Bouzerdoum

Faculty of Engineering and Information Sciences - Papers: Part A

This paper presents a new method for classification and characterization of voltage dips and swells in electricity networks. The proposed method exploits unique signatures and parameters of three phase voltage signals extracted from the polarization ellipse in three-dimensional (3D) co-ordinates. Five ellipse parameters, which include azimuthal angle, elevation, tilt, semi-minor axis and semi-major axis, are used to classify and characterize voltage dips and swells. Seven types of voltage dips, which include a total of 19 groups of dips incorporating different kinds of balanced (three-phase dips) and unbalanced (single-phase or double-phase) dips, are identified and successfully classified using the 3D polarization …


A Decentralized Multiagent-Based Voltage Control For Catastrophic Disturbances In A Power System, Sk. Razibul Islam, Kashem M. Muttaqi, Danny Sutanto Jan 2015

A Decentralized Multiagent-Based Voltage Control For Catastrophic Disturbances In A Power System, Sk. Razibul Islam, Kashem M. Muttaqi, Danny Sutanto

Faculty of Engineering and Information Sciences - Papers: Part A

In this paper, a multiagent-based voltage and reactive power control in the case of a multiple contingency is presented. Incorporating the agent-based autonomous feature to the intelligence of the remote terminal units, the present power system control structure can be used to help in preventing system voltage collapse during catastrophic disturbances. The control algorithm is based on a decentralized architecture of intelligent agents and the determination of a local zone that can carry out quick countermeasures in a decentralized manner as a multiagent system (MAS) during an emergency situation. An adaptive determination of the local zones undergoing voltage collapse has …


Improving Fault Ride-Through Of Three Phase Voltage Source Inverter During Symmetrical Fault Using Dc Link Fault Current Limiter, Mehrdad Tarafdar Hagh, Amin Jalilian, Seyed Behzad Naderi, Michael Negnevitsky, Kashem M. Muttaqi Jan 2015

Improving Fault Ride-Through Of Three Phase Voltage Source Inverter During Symmetrical Fault Using Dc Link Fault Current Limiter, Mehrdad Tarafdar Hagh, Amin Jalilian, Seyed Behzad Naderi, Michael Negnevitsky, Kashem M. Muttaqi

Faculty of Engineering and Information Sciences - Papers: Part A

The majority of distributed generation (DG) units utilize three phase voltage source inverter (VSI) to exchange electric power with the utility grid. The VSI employs semiconductor devices (SDs) with limited current withstand capabilities which are very vulnerable during grid faults. However, to ensure a secure and reliable operation of power systems at high penetration level of the DGs, most of the new grid codes worldwide require that the VSIs must have fault ride-Through (FRT) capability. This paper presents a DC link fault current limiter (DLFCL) based VSI FRT scheme to improve its FRT capability. In the proposed scheme, the DLFCL …


Community Energy Storage For Neutral Voltage Rise Mitigation In Four-Wire Multigrounded Lv Feeders With Unbalanced Solar Pv Allocation, Md Jan E Alam, Kashem M. Muttaqi, Danny Sutanto Jan 2015

Community Energy Storage For Neutral Voltage Rise Mitigation In Four-Wire Multigrounded Lv Feeders With Unbalanced Solar Pv Allocation, Md Jan E Alam, Kashem M. Muttaqi, Danny Sutanto

Faculty of Engineering and Information Sciences - Papers: Part A

The traditional neutral voltage problem in low-voltage (LV) four-wire multigrounded distribution networks can be aggravated due to an unbalanced allocation of one-phase photovoltaic (PV) units. Inherent limitations restrict the performance of the traditional strategies to mitigate the combined effect of load and PV unbalance. To overcome the shortcoming of traditional approaches, a new dynamic mitigation approach using community energy storage (CES) is proposed in this paper. A power balancing algorithm is developed to perform the balancing operation while minimizing power drawn from the CES. A charge/discharge control strategy is developed that will continuously balance and dynamically adjust the power exchange …