Engineering Commons^™

A Comprehensive Optimized Model For On-Board Solar Photovoltaic System For Plug-In Electric Vehicles: Energy And Economic Impacts, Mahmoud M. Abdelhamid

Mahmoud M Abdelhamid

Effects Of Neutron And Gamma Radiation On Lithium-Ion Batteries, Jie Qiu, Dandan He, Mingzhai Sun, Shimeng Li, Cun Wen, Jason Hattrick-Simpers, Yuan Zheng, Lei Cao

Jason R. Hattrick-Simpers

No abstract provided.

Capability Constraints To Mitigate Voltage Fluctuations From Dfig Wind Farms When Delivering Ancillary Services To The Network, Lasantha Meegahapola, S Perera

Dr Lasantha G Meegahapola

Majority of the wind power resources are typically sited at remote locations in power networks and generated power is transmitted through rural transmission corridors to load centres. With increased penetration level of the wind generation there is an increased requirement to provide ancillary services from distributed wind power resources, hence they are operated under different control strategies to provide ancillary services to the network. The control strategies and capability characteristics will significant impact on voltage fluctuations in distribution networks. This paper presents a comparative analysis between different wind generator control strategies (i.e. power factor control strategy, voltage control strategy and …

Characterisation Of Gas Turbine Dynamics During Frequency Excursions In Power Networks, Lasantha Meegahapola

Dr Lasantha G Meegahapola

Gas turbines inherently depict unique frequency response characteristics compared with other conventional synchronous generation technologies as their active power output is not entirely determined by the governor response during frequency deviations of the power network. Thus, gas turbine dynamics significantly influence on system stability during frequency events in power networks. Power system and power plant operators require improved understanding of the gas turbine characteristics during various frequency events in order to mitigate adverse impact on power system. Therefore a comparative analysis has been performed between combined-cycle gas turbines (CCGTs) and open-cycle gas turbines (OCGTs) in order to characterise the dynamic …

A Review Of Parallel Operation Of Active Power Filters In The Distributed Generation System, Shafiuzzaman Khadem, Malabika Basu, Michael Conlon

Dr. Shafiuzzaman Khan Khadem

In this paper a technical review of parallel operation of Active Power Filter (APF) for harmonic power compensation in distributed generation (DG) network has been presented. Controlling methods and connection topologies with their pros and cons are described. Recent improvements in controlling and future trends for the application of APFs in distributed mode are also identified.

Microgrids Of Commercial Buildings: Strategies To Manage Mode Transfer From Grid Connected To Islanded Mode, Lasantha Meegahapola, D Robinson, A Agalgaonkar, S Perera, P Ciufo

Dr Lasantha G Meegahapola

Microgrid systems located within commercial premises are becoming increasingly popular and their dynamic behavior is still uncharted territory in modern power networks. Improved understanding in design and operation is required for the electricity utility and building services design sectors. This paper evaluates the design requirements for a commercial building microgrid system to facilitate seamless mode transition considering an actual commercial building microgrid system. A dynamic simulation model of the proposed microgrid system is established (utilizing DIgSILENT Power Factory) to aid the development of planning and operational philosophy for the practical system. An economic operational criterion is developed for the microgrid …

Impact Of Renewable Power Integration On Vq Stability Margin, H. W. K. M. Amarasekara, Lasantha Meegahapola, Sarath Perera, Ashish Agalgaonkar

Dr Lasantha G Meegahapola

With the increasing number of grid connected renewable energy sources in power systems, the requirements for in-depth studies to characterise the dynamics of power systems have also intensified. In this paper, the impact of renewable power generators on power system voltage stability is analysed. As the renewable power penetration increases, having adequate levels of reactive power generation in power systems for voltage support is a major challenge. Therefore, in this work, special attention was placed on VQ instability to investigate static voltage stability of a test network embedded with renewable power generation. The impact of different control strategies associated with …

Impact Of Capacity Value Of Renewable Energy Resources On Raps System Energy Management, Lasantha Meegahapola, Y Tan, K Muttaqi

Dr Lasantha G Meegahapola

Renewable energy resources are widely being utilised in remote area power supply (RAPS) systems. The capacity value of renewable energy resources in a RAPS system indicates the ability of renewable energy resources to serve the load demand in the RAPS systems. In this paper, the impact of capacity value of renewable resources on energy management of a RAPS system, while maintaining system reliability, is investigated. It is revealed that capacity value of renewable energy resources has direct influence on RAPS system energy management. By utilising storage in conjunction with renewable energy resources, the RAPS system can cater load demand while …

Power Quality Emission Assessment Of Photovoltaic Inverters Based On Iec Technical Report 61000-3-15:2011, Lasantha Meegahapola, D Perera, P Ciufo, S Perera

Dr Lasantha G Meegahapola

The International Electrotechnical Committee Technical Report IEC 61000-3-15:2011 provides electromagnetic compatibility requirements and test conditions for distributed generators up to 75 A per phase. In the current research, two commercially available photovoltaic (PV) inverters up to the capacity of 3600 W were tested following the guidelines proposed in IEC 61000-3-15 in relation to low order harmonic emission and flicker emission. In addition, the harmonic and flicker emission behaviour of the PV inverters were investigated under varying irradiation conditions. Both PV inverters were observed to comply with the emission requirements prescribed by the technical report under most conditions except for even …

A Droop Control Based Load Sharing Approach For Management Of Renewable And Non-Renewable Energy Resources In A Remote Power System, Lasantha Meegahapola, Y Tan, K Muttaqi

Dr Lasantha G Meegahapola

Droop control is a load sharing strategy applied in conventional power systems. In this paper, droop control strategy has been adopted for the generators in a remote area power supply (RAPS) system in order to share active and reactive power load based on the rated capacities of the generators. Different characteristics of conventional and inverter-based energy resources make it difficult to share load in proportion to the rated capacities of the generators in a RAPS system. Therefore, this paper investigates the load sharing performance of different combinations of conventional and inverter-based energy resources in RAPS systems. The study scenarios investigated …

Aeroelastic Energy Harvesting Using A Nonlinear Electromagnetic Oscillator, Katherine Bender, Ndungu Muturi, Alex Spies, Christopher Lee

Christopher Lee

Results are presented from the design, fabrication and testing of an electromagnetic-inductor device to convert aeroelastic-induced oscillations of an airfoil into electricity. The energy harvester consists of three magnets configured such that the force-displacement relationship can be described by a fifth-degree polynomial. the integration of the harvester into a two-degree-of-freedom, pitch/plunge airfoil system introduces nonlinear stiffness into the plunge direction. This nonlinearity gives rise to limit cycle oscillations which, in turn, are converted to electric power by the harvester. Experimental measurements from wind tunnel tests are compared to predictions of limit cycle response and resulting power generation using a two-degree-of-freedom …

End-To-End Modeling For Variability And Reliability Analysis Of Thin Film Pv, Sourabh Dongaonkar, Muhammad Alam

Sourabh Dongaonkar

We present an end-to-end modeling framework, spanning the device, module and also system levels, for analyzing thin film photovoltaics (PV). This approach is based on embedding a detailed, statistically relevant, physics based equivalent circuit into module and array level simulations. This approach enables us to analyze key variability and reliability issues in thin film PV, and allows us to interpret their effect on process yield and intrinsic module lifetimes. Our results suggest that the time-zero gap between cell and module efficiencies, a key variability concern for thin-film PV, can be attributed to processrelated shunts with log-normal PDF distributed randomly across …

Reverse Stress Metastability Of Shunt Current In Cigs Solar Cells, Sourabh Dongaonkar, Erik Sheets, Rakesh Agrawal, Muhammad Alam

Sourabh Dongaonkar

Partial shading in thin film solar panels can result in reverse bias stress across shaded cells. Therefore, it is important to understand the effect of such reverse stress in commercially competitive PV technologies such as CIGS. In this paper, we systematically investigate the effect of moderate reverse bias on solution-processed CIGS solar cells. We subject the solar cells to varying degrees of reverse biases and continuously monitor the impact of the stress on dark current. We also explore the relaxation behavior of dark current following passive storage and the long term effect of the shadow stress on power output of …

Mle+: A Tool For Integrated Design And Deployment Of Energy Efficient Building Controls, Willy Bernal, Madhur Behl, Truong Nghiem, Rahul Mangharam

Truong X Nghiem

We present MLE+, a tool for energy-efficient building automation design, co-simulation and analysis. The tool leverages the high-fidelity building simulation capabilities of EnergyPlus and the scientific computation and design capabilities of Matlab for controller design. MLE+ facilitates integrated building simulation and controller formulation with integrated support for system identification, control design, optimization, simulation analysis and communication between software applications and building equipment. It provides streamlined workflows, a graphical front-end, and debugging support to help control engineers eliminate design and programming errors and take informed decisions early in the design stage, leading to fewer iterations in the building automation development cycle. …

Performance Investigation Of A Hybrid Renewable Power Generation And Storage System Using Systemic Power Management Models, Damianos Giaouris, Athanasios Papadopoulos, Chrysa Ziogou, Dimiptris Ipsakis, Spyors Voutetakis, Simira Papadopoulou, Panos Seferlis, Fotis Stergiopoulos, Costas Elmasides

Sakis Papadopoulos

Hybrid renewable power generation systems considering storage of energy and/or hydrogen involve considerable complexity as heterogeneous equipment need to be interconnected and activated or deactivated at different time instances. This work employs generic and flexible decision making models to develop complex power/hydrogen management strategies and investigate their performance on systems integrating multiple power generation and storage devices. These models significantly facilitate the analysis of both a standalone power generation and storage system forming a microgrid currently in operation as well as three interconnected microgrids of different functionalities considered in this work. These systems are used to investigate the performance of …

Green Scheduling For Radiant Systems In Buildings, Truong Nghiem, Madhur Behl, George Pappas, Rahul Mangharam

Rahul Mangharam

In this report we look at the problem of peak power reduction for buildings with electric radiant floor heating systems. Uncoordinated operation of a multi-zone radiant floor heating system can result in temporally correlated electricity demand surges or peaks in the building’s electricity consumption. As peak power prices are 200-400 times that of the nominal rate, this uncoordinated activity can result in high electricity costs and expensive system operation. We have previously presented green scheduling as an approach for reducing the aggregate peak power consumption in buildings while ensuring that indoor thermal comfort is always maintained. This report extends the …

Peak Wireless Power Transfer Using Magnetically Coupled Series Resonators, José Oscar Mur-Miranda, Giulia Fanti

José Oscar Mur-Miranda

Wireless power transfer can create the illusion of portable devices with infinite power supplies. Power transfer using magnetically coupled series resonators is maximized when the load presented to the sender is matched to the series impedance of the source. This determines an optimal separation distance between the sender and the receiver. However, the maximum power transferred only depends on the losses in the system and is independent of this distance and the resonant frequency. Closed-form expressions describe the power transferred and efficiency for all distances and system values. These expressions are validated with systems operating at 23 kHz, 40 kHz …

Wireless Power Transfer Using Weakly Coupled Magnetostatic Resonators, José Oscar Mur-Miranda, Giulia Fanti, Yifei Feng, Keerthik Omanakuttan, Roydan Ongie, Albert Setjoadi, Natalie Sharpe

José Oscar Mur-Miranda

Wireless power transfer can create the illusion of portable devices with infinite power supplies and enable applications that are currently unimaginable because of power constraints. Magnetic induction has been extensively used for wireless power transfer, but its efficiency depends on magnetic coupling that decays as the inverse cube of distance. At long enough distances, the magnetic coupling is weak enough that the effect of the receiver coil on the sender coil can be neglected. In this weakly coupled limit, series resonance in both the sender and the receiver increases the power transfer. Compared to magnetic induction, the power transfer increases …

Evolution Of A Folded Floating-Gate Differential Pair, Bradley Minch

Bradley Minch

The author presents a folded floating-gate MOS (FGMOS) differential pair circuit that is capable of simultaneously providing a rail-to-rail common-mode input voltage range and a rail-to-rail output voltage swing with a low power-supply voltage. In this configuration, the voltage drop across the bias current source is folded up into the same range over which the output voltages swing, facilitating low-voltage operation. The floating-gate charge can be used to trim out the offset voltage of the differential pair and to reduce the required power-supply voltage for a given bias current level. The author provides both a qualitative description of how the …

Dynamic Modeling And Analysis Of Single-Stage Boost Inverters Under Normal And Abnormal Conditions, Ali Kaviani

Ali Kaviani

No abstract provided.

Efficient Database Generation For Decision Tree Based Power System Security Assessment, Venkat Krishnan

Venkat Kumar Krishnan

No abstract provided.

The Impact Of Quality Management Systems During A Pebble Bed Modular Reactor Project : A Case Study, Lwandiso Zamxaka

Lwandiso L Zamxaka

In the nuclear industry, Quality Management Systems are extremely important,especially if one wishes to improve public acceptance of radioactive solutions.There is normally minimum communication between the public and scientists,especially in nuclear science. People are not comfortable with nuclear technology,based on the past history of the Chernobyl catastrophe. Consequently, it is difficult to discuss important and sensitive issues like disposing of nuclear waste. Quality Management Systems can improve public confidence and communication. Integrated Management Systems in the project planning stage of the project can be a proactive step towards preventing unnecessary delays and costs. There is a perception that quality is …