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Power Loss And Thermal Impedance Modeling Of Multilevel Power Converter With Discontinuous Modulation, Md Mazharul Islam, Md. Ashib Rahman, Md Rabiul Islam Jan 2020

Power Loss And Thermal Impedance Modeling Of Multilevel Power Converter With Discontinuous Modulation, Md Mazharul Islam, Md. Ashib Rahman, Md Rabiul Islam

Faculty of Engineering and Information Sciences - Papers: Part B

The hard switching operation of the insulated gate bipolar transistor (IGBT)-based multilevel converters (MLCs) in the transformer less direct integration of renewable power plants produces a considerable amount of switching and conduction power loss. This eventually causes higher junction temperature and lower thermal stability. The third harmonic sixty-degree bus-clamped pulse width modulation (BCPWM) technique demonstrates reduced switching losses and better harmonic spectra. In this paper, an analytical model for calculating the average and the rms currents for the hard switching operation of IGBTs and antiparallel diodes (APDs) is proposed. Furthermore, to calculate the device turn-on and turn-off losses, a discrete …


A New Modulation Technique To Improve The Power Loss Division Performance Of The Multilevel Inverters, Md Razon Chowdhury, Md. Ashib Rahman, Md Rabiul Islam, A M. Mahfuz-Ur-Rahman Jan 2020

A New Modulation Technique To Improve The Power Loss Division Performance Of The Multilevel Inverters, Md Razon Chowdhury, Md. Ashib Rahman, Md Rabiul Islam, A M. Mahfuz-Ur-Rahman

Faculty of Engineering and Information Sciences - Papers: Part B

Multilevel inverters (MLIs) have offered significant contributions towards the implementation of energy conversion units used in industry and renewable energy applications. However, the switching devices in MLIs are associated with power loss division problems. The pulse width modulation (PWM) techniques greatly influence the peak, average, and ripple values of the device junction temperature. Thermal tension in the devices may be raised due to increased power loss caused by additional switching or uneven distribution of losses due to unbalanced gate pulses. Higher thermal stress accelerates the life degradation process of the power devices and eventually, leads to permanent damage of the …


A New Data Driven Long-Term Solar Yield Analysis Model Of Photovoltaic Power Plants, Biplob Ray, Rakibuzzaman Shah, Md Rabiul Islam, Syed Islam Jan 2020

A New Data Driven Long-Term Solar Yield Analysis Model Of Photovoltaic Power Plants, Biplob Ray, Rakibuzzaman Shah, Md Rabiul Islam, Syed Islam

Faculty of Engineering and Information Sciences - Papers: Part B

Historical data offers a wealth of knowledge to the users. However, often restrictively mammoth that the information cannot be fully extracted, synthesized, and analyzed efficiently for an application such as the forecasting of variable generator outputs. Moreover, the accuracy of the prediction method is vital. Therefore, a trade-off between accuracy and efficacy is required for the data-driven energy forecasting method. It has been identified that the hybrid approach may outperform the individual technique in minimizing the error while challenging to synthesize. A hybrid deep learning-based method is proposed for the output prediction of the solar photovoltaic systems (i.e. proposed PV …


Model Predictive Control For A New Magnetic Linked Multilevel Inverter To Integrate Solar Photovoltaic Systems With The Power Grids, A M. Mahfuz-Ur-Rahman, Md Rabiul Islam, Kashem M. Muttaqi, Danny Sutanto Jan 2020

Model Predictive Control For A New Magnetic Linked Multilevel Inverter To Integrate Solar Photovoltaic Systems With The Power Grids, A M. Mahfuz-Ur-Rahman, Md Rabiul Islam, Kashem M. Muttaqi, Danny Sutanto

Faculty of Engineering and Information Sciences - Papers: Part B

The multilevel inverters are becoming increasingly popular for use in the grid integration of wind and photovoltaic (PV) power plants due to their higher voltage handling capability and the better output power quality. There are several types of multilevel inverters that have been proposed in the literature; among them the active neutral point clamp (ANPC) multilevel inverters have been drawing significant attention specially for solving the problems with other multilevel inverters. However, with the increase of number of levels, the ANPC requires more electronic switches and flying capacitors, by which the complexity and the cost increases. In this paper, an …


Increase In Volumetric Electrical Power Density Of A Linear Generator By Winding Optimization For Wave Energy Extraction, Selim Molla, Omar Farrok, Abidur Rahman, Md Samiul Bashir, Md Rabiul Islam, Abbas Z. Zouzani, M. A Parvez Mahmud Jan 2020

Increase In Volumetric Electrical Power Density Of A Linear Generator By Winding Optimization For Wave Energy Extraction, Selim Molla, Omar Farrok, Abidur Rahman, Md Samiul Bashir, Md Rabiul Islam, Abbas Z. Zouzani, M. A Parvez Mahmud

Faculty of Engineering and Information Sciences - Papers: Part B

In this article, a method of winding optimization of the linear generator is proposed to increase the electrical power generation from the oceanic wave. A linear generator is designed in the ANSYS/Maxwell environment to analyze the proposed winding optimization method. The electrical and magnetic properties of the generator are extensively analyzed. The cross-sectional area and the number of turns of the copper conductor are optimized to maximize the output power. Load characteristics are also considered for different conductor sizes and turn numbers to determine a suitable operating point. A cooling system is also incorporated in the optimized linear generator to …


A New Generalized Step-Down Single-Stage Ac/Ac Power Converter, Md Shihab Uddin, Shuvra Prokash Biswas, Md Rabiul Islam, Md Shamim Anower, Abbas Z. Kouzani, M Parvez Mahmud Jan 2020

A New Generalized Step-Down Single-Stage Ac/Ac Power Converter, Md Shihab Uddin, Shuvra Prokash Biswas, Md Rabiul Islam, Md Shamim Anower, Abbas Z. Kouzani, M Parvez Mahmud

Faculty of Engineering and Information Sciences - Papers: Part B

Most traditional AC/AC power converters suffer from power quality problems and multi-stage power conversion losses. The rectifier and inverter-based AC/AC converter topology not only increases multi-stage power conversion losses, but also increases the volume, weight, and cost, and decreases the longevity of the converter due to the DC-link capacitor, line filter and electromagnetic interference (EMI) filter. High-frequency (about 10 kHz) switching advanced pulse width modulation techniques are generally used in order to compensate the power quality problems, which increase the switching losses and introduce the EMI problems. In this paper, a new generalized step-down single-stage line-frequency switching AC/AC power converter …


Joint Transmission Power Control And Relay Cooperation For Wban Systems, Hongyun Zhang, Farzad Safaei, Le Chung Tran Jan 2018

Joint Transmission Power Control And Relay Cooperation For Wban Systems, Hongyun Zhang, Farzad Safaei, Le Chung Tran

Faculty of Engineering and Information Sciences - Papers: Part B

Improving transmission reliability is a crucial challenge for Wireless Body Area Networks (WBANs) because of the instability of channel conditions and the stringent Packet Loss Ratio (PLR) requirement for many WBANs applications. On the other hand, limited by the size of WBAN nodes, the energy consumption of WBAN nodes should be minimized. In this paper, we jointly consider transmission power control, dynamic slot scheduling and two-hop cooperative mechanism and propose an Autocorrelation-based Adaptive Transmission (AAT) scheme that achieves a better trade-off between transmission reliability and energy consumption for WBAN systems. The new scheme is designed to be compatible with IEEE …


Autocorrelation Based Transmission Power Control In Wbans, Hongyun Zhang, Farzad Safaei, Le Chung Tran Jan 2018

Autocorrelation Based Transmission Power Control In Wbans, Hongyun Zhang, Farzad Safaei, Le Chung Tran

Faculty of Engineering and Information Sciences - Papers: Part B

In this paper, we propose an autocorrelation-based transmission power control (A-TPC) method to increase the transmission reliability and reduce the energy consumption. In A-TPC, data packets from multiple sensor nodes are scheduled in the TDMA-fashion. The transmission power level and the slot scheduling are jointly optimized based on a temporal autocorrelation model. The channel datasets collected from real WBAN daily scenarios are imported into our simulation model to evaluate the performance of A-TPC. Simulation results demonstrate that A-TPC significantly improves the transmission reliability and reduces the energy consumption.


Observer-Based Load Frequency Control For Island Microgrid With Photovoltaic Power, Chaoxu Mu, Weiqiang Liu, Wei Xu, Md Rabiul Islam Jan 2017

Observer-Based Load Frequency Control For Island Microgrid With Photovoltaic Power, Chaoxu Mu, Weiqiang Liu, Wei Xu, Md Rabiul Islam

Faculty of Engineering and Information Sciences - Papers: Part B

As renewable energy is widely integrated into the power system, the stochastic and intermittent power generation from renewable energy may cause system frequency deviating from the prescribed level, especially for a microgrid. In this paper, the load frequency control (LFC) of an island microgrid with photovoltaic (PV) power and electric vehicles (EVs) is investigated, where the EVs can be treated as distributed energy storages. Considering the disturbances from load change and PV power, an observer-based integral sliding mode (OISM) controller is designed to regulate the frequency back to the prescribed value, where the neural network observer is used to online …


Integration Of Plug-In Electric Vehicles Into Microgrids As Energy And Reactive Power Providers In Market Environment, Abdorreza Rabiee, Hassan Feshki Farahani, Mohammad Khalili, Jamshid Aghaei, Kashem M. Muttaqi Jan 2016

Integration Of Plug-In Electric Vehicles Into Microgrids As Energy And Reactive Power Providers In Market Environment, Abdorreza Rabiee, Hassan Feshki Farahani, Mohammad Khalili, Jamshid Aghaei, Kashem M. Muttaqi

Faculty of Engineering and Information Sciences - Papers: Part A

The concept of electricity markets in the deregulated environment generally refers to energy market and reactive power market is not paid attention as much as it deserves to. However, reactive power plays an important role in distribution networks to improve network conditions such as voltage profile improvement and loss reduction. Plug-in electric vehicles (PEVs) are mobile sources of active and reactive power, capable of being participated in energy market, and also in reactive power market without battery degradation. Active and reactive powers are coupled through the ac power flow equations and branch loading limits, as well as PEVs and synchronous …


A High Availability Application Service Platform For Nuclear Power Enterprises, Zhe Sun, He Jin, Jianming Yong, Salim Al Isma'ili, Changying Li, Jun Shen Jan 2016

A High Availability Application Service Platform For Nuclear Power Enterprises, Zhe Sun, He Jin, Jianming Yong, Salim Al Isma'ili, Changying Li, Jun Shen

Faculty of Engineering and Information Sciences - Papers: Part A

This paper presents a High Availability Application Service Platform (HAASP) and analyses its high availability. The architecture of this platform contains application server platform and high availability architecture. Application server platform consists of three major components, application release platform, which is implemented with WebLogic and WebSphere cluster, application and database platforms, which are built with Oracle RAC, and IBM Domino cluster. High availability architecture is constructed by virtual machines, distributed switches and storage pools. It employs virtualization technology to integrate physical servers and storages, where physical servers are responsible for the creation of virtual server cluster, distributed switches, storage pool …


A New Approach To Reduce The Expected Energy Not Supplied In A Power Plant Located In A Non-Expandable Transmission System, Hadi Lomei, Danny Sutanto, Kashem M. Muttaqi, Mohsen Assili Jan 2015

A New Approach To Reduce The Expected Energy Not Supplied In A Power Plant Located In A Non-Expandable Transmission System, Hadi Lomei, Danny Sutanto, Kashem M. Muttaqi, Mohsen Assili

Faculty of Engineering and Information Sciences - Papers: Part A

The main objective of most of power plants is to inject power as much as possible into the grid from the power plants. However, the transmission system may restrain the output capability of the power plant, especially, if the power plant is located in an area of non-expandable transmission system. In this situation, any disturbance in the nearby transmission system may force the plant to generate lower than its rated value, which disables it from selling the remaining available generated power to the costumers and also increases the cost of energy not supplied. In this paper, an efficient method is …


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 …


A New Approach To Reduce The Non-Linear Characteristics Of A Stressed Power System By Using The Normal Form Technique In The Control Design Of The Excitation System, Hadi Lomei, Danny Sutanto, Kashem M. Muttaqi, Mohsen Assili Jan 2015

A New Approach To Reduce The Non-Linear Characteristics Of A Stressed Power System By Using The Normal Form Technique In The Control Design Of The Excitation System, Hadi Lomei, Danny Sutanto, Kashem M. Muttaqi, Mohsen Assili

Faculty of Engineering and Information Sciences - Papers: Part A

In this paper, a new approach is presented to reduce the nonlinear characteristics of a stressed power system by reducing its second-order modal interaction through retuning some parameters of the generator excitation system. In order to determine the second-order modal interaction of the system, a new index on nonlinearity is developed using normal form theory. Using the proposed index of nonlinearity, a sensitivity function is formed to indicate the most effective excitation system parameters in the nonlinear behavior of the system. These dominant parameters are tuned to reduce the second-order modal interaction of the system and to reduce the index …


Power Generation Analysis Of Powerwindow, A Linear Wind Generator, Using Computational Fluid Dynamic Simulations, Seyed A. Jafari, Farzad Safaei, Buyung Kosasih, K C. Kwok Jan 2015

Power Generation Analysis Of Powerwindow, A Linear Wind Generator, Using Computational Fluid Dynamic Simulations, Seyed A. Jafari, Farzad Safaei, Buyung Kosasih, K C. Kwok

Faculty of Engineering and Information Sciences - Papers: Part A

A new linear wind generator (LWG), named PowerWindow, is introduced. The modular and scalable LWG is capable of generating power in low wind velocity condition, and hence can be an effective and safe power generator in built environments. The aerodynamic mechanism of the LWG power generation is elucidated using computational fluid dynamic (CFD) simulations, and the results are validated against the experimental data obtained from the prototype wind tunnel tests. The simulations provide important insights into the flow field in and around LWG particularly over the front and rear blades and how each one contributes to the power generation. This …


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 …


Summary Of The Economic Impacts Of Power Quality On Consumers, Sean T. Elphick, Philip Ciufo, Victor W. Smith, Sarath Perera Jan 2015

Summary Of The Economic Impacts Of Power Quality On Consumers, Sean T. Elphick, Philip Ciufo, Victor W. Smith, Sarath Perera

Faculty of Engineering and Information Sciences - Papers: Part A

The quality of the electrical supply has a direct impact on the correct function and operation of equipment connected to the public electricity supply network. There is an expectation that devices will operate as designed and that equipment lifetime should, statistically, be close to the designed value. The reliability of the network is generally assumed to be high enough so as to not cause unacceptable issues with regard to loss of production or loss of functionality. Quantifying the cost to the consumer when the supply power quality or reliability are not as expected is an important metric and can be …


Direct Power Control Of Dfig Based Wind Turbine Based On Wind Speed Estimation And Particle Swarm Optimization, Mehrdad Tarafdar Hagh, S Roozbehani, F Najaty, S Ghaemi, Yingjie Tan, Kashem M. Muttaqi Jan 2015

Direct Power Control Of Dfig Based Wind Turbine Based On Wind Speed Estimation And Particle Swarm Optimization, Mehrdad Tarafdar Hagh, S Roozbehani, F Najaty, S Ghaemi, Yingjie Tan, Kashem M. Muttaqi

Faculty of Engineering and Information Sciences - Papers: Part A

This paper presents a direct power control (DPC) design of a grid connected doubly fed induction generator (DFIG) based wind turbine system in order to track maximum absorbable power in different wind speeds. A generalized regression neural network (GRNN) is used to estimate wind speed and thereby the maximum absorbable power is determined online as a function of wind speed. Finally the proposed DPC strategy employs a nonlinear robust sliding mode control (SMC) scheme to calculate the required rotor control voltage directly. The concept of sliding mode control is incorporated into particle swarm optimization (PSO) to determine inertial weights. The …


Simple Structure For Reactive Power Control Of Ac Photovoltaic Modules, Viet Thang Tran, Danny Sutanto, Kashem M. Muttaqi Jan 2015

Simple Structure For Reactive Power Control Of Ac Photovoltaic Modules, Viet Thang Tran, Danny Sutanto, Kashem M. Muttaqi

Faculty of Engineering and Information Sciences - Papers: Part A

The objective of this paper is to propose a simple structure for reactive power control (RPC) of AC Photovoltaic (AC PV) modules. With the proposed structure, a cost-effective microcontroller can be adopted to achieve an effective reactive power control in order to support the grid voltage within acceptable bounds by absorbing or supplying reactive power. Moreover, the sliding mode control (SMC) is adopted to enhance the current control's dynamic response and reduce the current harmonic distortion. Comprehensive simulation of an AC PV module connected to grid using PSIM software with different operation modes are used to demonstrate the control strategy. …


Enhanced Frequency Response Strategy For Pmsg Based Wind Energy Conversion System Using Ultracapacitor In Remote Area Power Supply Systems, Yingjie Tan, Kashem M. Muttaqi Jan 2015

Enhanced Frequency Response Strategy For Pmsg Based Wind Energy Conversion System Using Ultracapacitor In Remote Area Power Supply Systems, Yingjie Tan, Kashem M. Muttaqi

Faculty of Engineering and Information Sciences - Papers: Part A

The high penetration level of wind energy, and non-responsive nature of power electronic interfaced wind energy conversion system (WECS) during frequency variations may create significant stress on conventional generators in a wind-diesel hybrid remote area power supply (RAPS) system. Hence, it is a necessity for WECS to provide frequency support. However, conventional frequency control strategies being used for WECS may impose a severe stress to wind turbines. In this paper, an enhanced frequency response strategy is proposed for the permanent magnet synchronous generator (PMSG) based WECS to regulate RAPS system frequency jointly with its integrated ultracapacitors. The proposed frequency response …


On Using Wireless Power Transfer To Increase The Max Flow Of Rechargeable Wireless Sensor Networks, Tengjiao He, Kwan-Wu Chin, Sieteng Soh Jan 2015

On Using Wireless Power Transfer To Increase The Max Flow Of Rechargeable Wireless Sensor Networks, Tengjiao He, Kwan-Wu Chin, Sieteng Soh

Faculty of Engineering and Information Sciences - Papers: Part A

A key problem in Rechargeable Wireless Sensor Networks (WSNs) is determining the maximum amount of data that can be collected by a sink over a given time period. This maximum is constrained by link capacity and critically, by the available energy at each node. In this paper, we consider a novel approach to increase the maximum flow rate by exploiting recent advances in Wireless Power Transfer (WPT). Specifically, we deploy a finite number of WPT capable rovers next to bottleneck sensor nodes with the aim to increase the max flow rate of a WSN. We formulate a Mixed Integer Linear …


Suboptimal Mppt Control For Power Management In Pv-Diesel Remote Area Power Supply Systems, Yingjie Tan, Lasantha G. Meegahapola, Kashem M. Muttaqi Jan 2014

Suboptimal Mppt Control For Power Management In Pv-Diesel Remote Area Power Supply Systems, Yingjie Tan, Lasantha G. Meegahapola, Kashem M. Muttaqi

Faculty of Engineering and Information Sciences - Papers: Part A

Maximum power point tracking (MPPT) is commonly being used in solar-photovoltaic (PV) power generation systems to maximise solar energy extraction. In this paper it is proposed to operate the solar-PV system at the suboptimal MPPT to manage power balance in a remote area power supply (RAPS) system. This is performed based on three different operating modes: 1) Frequency control mode; 2) Active power control mode; 3) MPPT control mode. The operating modes are decided based on the load level and the operating mode of the diesel generator (i.e. synchronous condenser mode or generator mode). This power management strategy balances the …


A Noniterative Method To Estimate Load Carrying Capability Of Generating Units In A Renewable Energy Rich Power Grid, Md Abu Abdullah, Kashem M. Muttaqi, Ashish Agalgaonkar, Danny Soetanto Jan 2014

A Noniterative Method To Estimate Load Carrying Capability Of Generating Units In A Renewable Energy Rich Power Grid, Md Abu Abdullah, Kashem M. Muttaqi, Ashish Agalgaonkar, Danny Soetanto

Faculty of Engineering and Information Sciences - Papers: Part A

It is important to estimate the contribution of renewable generation units in the evaluation of system generation adequacy for power generation planning taking into account the demand and renewable generation correlation and uncertainty. The effective load carrying capability (ELCC) is usually used for this purpose. In this paper, a noniterative analytical method is proposed for estimating the peak load carrying capability (PLCC) and ELCC of conventional and renewable generation units. The proposed method is verified using the IEEE RTS and an electricity network in New South Wales, Australia, and the results are compared with other estimation methods. The results show …


Assessing Network Compliance For Power Quality Performance, Sean Elphick, Victor Gosbell, Victor Smith, Gerrard Drury, Robert Barr Jan 2014

Assessing Network Compliance For Power Quality Performance, Sean Elphick, Victor Gosbell, Victor Smith, Gerrard Drury, Robert Barr

Faculty of Engineering and Information Sciences - Papers: Part A

IEC standards suggest that a network is compliant if 95% of the sites are compliant. In many cases it is only practical to measure the PQ parameters of some of the sites in a network and to use statistical analysis. The paper examines the minimum number of monitored sites needed to demonstrate compliance with a prescribed degree of confidence - e.g. at the 95% confidence level. Analysis is made of samples extracted randomly from sites included in the Australian Long Term National PQ Survey. The required number of sites is found to vary with the PQ disturbance of concern and …


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. …


Energy-Efficiency Analysis Of Per-Subcarrier Antenna Selection With Peak-Power Reduction In Mimo-Ofdm Wireless Systems, Ngoc Phuc Le, Le Chung Tran, Farzad Safaei Jan 2014

Energy-Efficiency Analysis Of Per-Subcarrier Antenna Selection With Peak-Power Reduction In Mimo-Ofdm Wireless Systems, Ngoc Phuc Le, Le Chung Tran, Farzad Safaei

Faculty of Engineering and Information Sciences - Papers: Part A

The use of per-subcarrier antenna subset selection in OFDM wireless systems offers higher system capacity and/or improved link reliability.However, the implementation of the conventional per-subcarrier selection schememay result in significant fluctuations of the average power and peak power across antennas, which affects the potential benefits of the system. In this paper, power efficiency of high-power amplifiers and energy efficiency in per-subcarrier antenna selection MIMO-OFDM systems are investigated. To deliver the maximum overall power efficiency, we propose a two-step strategy for data-subcarrier allocation.This strategy consists of an equal allocation of data subcarriers based on linear optimization and peak-power reduction via cross-antenna …


Power Allocation Algorithm In Ofdm-Based Cognitive Radio Systems, Van Vinh Nguyen, Yang Shouyi, Le Chung Tran Jan 2014

Power Allocation Algorithm In Ofdm-Based Cognitive Radio Systems, Van Vinh Nguyen, Yang Shouyi, Le Chung Tran

Faculty of Engineering and Information Sciences - Papers: Part A

In orthogonal frequency division multiplexing (OFDM)-based cognitive radio (CR) systems, the optimized algorithms for sub-carrier power allocation face the problems of complex iterative calculation and difficult realization. In this paper, we propose an exponential power distribution function and derive a sub-optimal power allocation algorithm. This algorithm aims to allocate power of in-band subcarriers of cognitive users according to the numerical characteristics of the power distribution function by using a convex optimization numerical method under linear constraints. This algorithm has the advantages of fast calculation speed and easy realization, and reduces the interference to the authorized users, which is caused by …


Transmit Antenna Subset Selection For High-Rate Mimo-Ofdm Systems In The Presence Of Nonlinear Power Amplifiers, Phuc Ngoc Le, Farzad Safaei, Le Chung Tran Jan 2014

Transmit Antenna Subset Selection For High-Rate Mimo-Ofdm Systems In The Presence Of Nonlinear Power Amplifiers, Phuc Ngoc Le, Farzad Safaei, Le Chung Tran

Faculty of Engineering and Information Sciences - Papers: Part A

The deployment of antenna subset selection on a per-subcarrier basis in MIMO-OFDM systems could improve the system performance and/or increase data rates. This paper investigates this technique for the MIMO-OFDM systems suffering nonlinear distortions due to high-power amplifiers. At first, some problems pertaining to the implementation of this antenna selection approach, including power imbalance across transmit antennas and non-causality of per-subcarrier antenna selection criteria, are identified. Next, an optimal selection scheme is devised by means of linear optimization to overcome those disadvantages. This scheme optimally allocates data subcarriers under a constraint that all antennas have the same number of data …


A Review Of Technical Challenges In Planning And Operation Of Remote Area Power Supply Systems, Yingjie Tan, Lasantha Meegahapola, Kashem M. Muttaqi Jan 2014

A Review Of Technical Challenges In Planning And Operation Of Remote Area Power Supply Systems, Yingjie Tan, Lasantha Meegahapola, Kashem M. Muttaqi

Faculty of Engineering and Information Sciences - Papers: Part A

Remote area power supply (RAPS) systems are being used for many years to supply power to rural or remote communities where the utility grid is not accessible. In order to avoid the high operating cost and environmental impact caused by conventional generators, renewable energy resources are currently being utilised in RAPS systems. However, the intermittency of such renewable energy resources greatly impacts on planning and operation of RAPS systems. This paper aims to present a comprehensive review with regard to the RAPS system planning and operation techniques published in the literature. This paper summarises different modelling approaches associated with the …


Dispatch Strategy To Minimise Uncertainty In Wind Power Generation In The Australian National Electricity Market, Amila Wickramasinghe, Lasantha G. Meegahapola, Ashish P. Agalgaonkar, Sarath Perera Jan 2014

Dispatch Strategy To Minimise Uncertainty In Wind Power Generation In The Australian National Electricity Market, Amila Wickramasinghe, Lasantha G. Meegahapola, Ashish P. Agalgaonkar, Sarath Perera

Faculty of Engineering and Information Sciences - Papers: Part A

2014 ACPE. With increased penetration of wind power, scheduling generators to meet the forecast demand of a power system is becoming an increasingly challenging task for the system operators. Uncertainty associated with the generation expected from wind plants adds to the load demand uncertainty, making it necessary to retain additional reserves to maintain the balance between demand and supply of power. In the Australian national electricity market (NEM), sophisticated wind forecasting techniques are employed to reduce the uncertainty in wind generation. Despite being able to project the contribution of wind power to a reasonable accuracy, wind power plants are currently …