Research Title: Grid-Connected Multilevel Topology for HVDC Offshore Wind Farm Based on MFT

Author: Firas Abdullah Obeidat, Published Year: 2013

. Power Electronics Technology Journal,

Faculty: Engineering and Technology

Abstract: This paper presents a new topology to connect HVDC offshore wind farm into the grid; the offshore part consist of five units, each unit contain permanent magnet synchronous generator (PMSG) connected to 3-phase/3-phase matrix converter (MC) to control the generator speed by using a MPPT control. The offshore platform consists of a three phase Medium Frequency Transformer (MFT) and a three phase Modular Multilevel Converter (MMC); the primary of each phase of the transformer connected to one phase from each unit. The secondary of the transformer connected to three phase MMC to get High Voltage DC (HVDC). The HVDC cable will be used to transfer power from the offshore side to the onshore side. Five levels MMC is used in the onshore side to control the DC voltage and to connect the offshore wind farm into the Grid by converting the HVDC to HVAC.

Keywords: PMSG; Three Phase Matrix Converter; MFT; MMC; Series DC Wind Farm

Research Title: Grid-Connected Multilevel Topology for HVDC Offshore Wind Farm

Author: Firas Abdullah Obeidat, Published Year: 2013

Electric machines and Control,

Faculty: Engineering and Technology

Abstract: This paper presents a topology to connect HVDC offshore wind farm into the grid; the offshore part consist of five units, each one contains permanent magnet synchronous generator (PMSG) connected to a three level neutral point clamped converter (3L-NPC) which works as a rectifier to control the generator speed by using a maximum power point tracking (MPPT) control. The offshore platform consists of a half bridge connected in series to balance the voltage between units and to collect the voltage in order to get the desired DC voltage. The HVDC cable will be used to transfer power from the offshore side to the onshore side. A Modular Multilevel Converter (MMC) is used in the onshore side to convert the voltage from DC to AC voltage and to connect the offshore wind farm into the Grid.

Keywords: PMSG; 3L-NPC; Half Bridge; MMC; Series DC Wind Farm.

Research Title: Reliability Prediction of PV Inverters Based on MIL-217F N2

Author: Firas Abdullah Obeidat, Published Year: 2015

42nd IEEE Photovoltaic Specialists Conference (42nd IEEE PVSC), New Orleans, USA

Faculty: Engineering and Technology

Abstract: This paper initially discusses the reliability of a 250W Photovoltaic (PV) micro inverter. Using the bill of materials the reliabilities of the main, gate drive, power supply, current and voltage sensing and microprocessor circuits were investigated, and the failure rate and Mean Time Between Failure (MTBF) calculated. The sum of component failure rates equals the complete PV micro inverter failure rate. To account for temperature effects the component failure rate was calculated for each inverter operating temperature, and multiplied by the percentage occurrence of this operating temperature to obtain a weighted failure rate. A similar procedure was used to calculate the failure rate for the main circuits of a 4.6kW & a 4.5kW multi-string inverter. All calculations are based on MIL-17F N2 method.

Keywords: Failure rate, MIL-HDBK-217F N2, PV micro inverter, PV multi string inverter, Reliability prediction.

Research Title: Simulation of Grid Connected HVDC Offshore Wind Farm Topologies

Author: Firas Abdullah Obeidat, Published Year: 2013

The 10th IEEE International Conference on Power Electronics and Drive Systems (PEDS2013), Kitakyushu, Japan

Faculty: Engineering and Technology

Abstract: This paper presents two topologies to connect HVDC offshore wind farm into the grid, the offshore part consist of five units; in the first topology, each unit contains a permanent magnet synchronous generator (PMSG) connected to a three level neutral point clamped converter (3L-NPC) to control the generator speed by using a maximum power point tracking (MPPT) control. The offshore platform consists of a half bridge connected in series to balance the voltage between the units and to collect the voltage in order to get the desired DC voltage. In the second topology, each unit contains a PMSG connected to 3-phase/3-phase matrix converter (MC) to control the generator speed by using a MPPT control. The offshore platform consists of a three phase High Frequency Transformer (HFT); the primary of each phase of the transformer connected to one phase from each unit. The secondary of the transformer connected to three phase diode bridge rectifier to get HVDC. The HVDC cable is used to transfer power from the offshore side to the onshore side. A Modular Multilevel Converter (MMC) is used in the onshore side to convert the voltage from DC to AC voltage and to integrate the offshore wind farm into the Grid.

Keywords: PMSG, MPPT, 3L-NPC, Half Bridge, Matrix Converter, HFT, MMC, HVDC Offshore Wind Farm.

Research Title: The Application of Three Level NPC Converter for Wind Power Generator

Author: Firas Abdullah Obeidat, Published Year: 2012

2012 IEEE 7th International Power Electronics and Motion Control Conference - ECCE Asia, Harbin, China

Faculty: Engineering and Technology

Abstract: This paper presents the control of a three level back to back converter with Permanent Magnet Synchronous Machine (PMSM). Field Oriented Control (FOC) is used to control the speed and the current of PMSM. Space Vector Pulse Width Modulation (SVPWM) is used to control the Three Level Rectifier and the Three Level Voltage Source Inverter. The simulation tests of the system have been developed based on Simulink/Matlab.

Keywords: Wind Turbine; Three phase Three Level Convertr; PMSM; SVPWM.

Research Title: Software Evolution: A Features Variability Modeling Approach

Author: Said Ahmad Ammar Ghoul, Published Year: 2016

Journal of Software Engineering, 10 (5)

Faculty: Information Technology

Abstract: Abstract: Background: Software Product Lines (SPLs) have been used successfully for building software systems families. One of techniques that are widely used to support SPL’s variability modelling is feature modelling. These methods have been used to recognize and manage commonalities and variability among products. But like anything in this world, software systems families are rapidly changing and demanding for more dynamic capabilities. Materials and Methods: One of the challenging problems of dynamic SPLs is that feature modelling techniques are unable to support dynamic capabilities and their formalization. In fact, feature modelling techniques support well elementary features, but the composed ones are not yet supported nor formalized. This study aims to deal with this challenge. It extends the conventional elementary feature modelling concepts, with composed feature and inherent relations concepts. According to bio-inspired approach, a software configuration comes up by composing its features from elementary or any other composed features. Then this configuration may evolve through its life cycle by metamorphosing, changing from a composed feature to another. Results: This software feature-based evolution variability modelling technique has led to an introduction of a new methodology producing an extended feature model by new meta features and relations. The combination of two formalisms in the specification of this methodology is more powerful than a unique one. Conclusion: The obtained results compared to the actual approaches seem to be promising. The bio-inspired software evolution has led to identify weaknesses of currents feature-based evolution approaches. The introduction of new powerful feature modelling concepts and supporting formal approach, inspired from nature is expected to promote the software evolution.

Keywords: Feature model, Variablity modelling, Software productlines, software evolution, software configuration

Research Title: A Road Map to Bio-inspired Software Engineering

Author: Said Ahmad Ammar Ghoul, Published Year: 2016

Research Journal of Information Technology, 8 (3)

Faculty: Information Technology

Abstract: Abstract: Background: Software production study is rapidly evolving in two parallel approaches: Conventional and bio-inspired. Bio-inspired approaches are generally developed and presented as enhancements of conventional ones. However, conventional approaches benefit from their integration with their global context, through software engineering methodologies for being advantageous. Materials and Methods: The integration of bio-inspired approaches, with bio-inspired software engineering methodologies will enrich bio-inspired approaches and let them be irrefutably the best. This study identifies the motivations of the emergence of such bio-inspired software engineering, presents a first approach to it with a road map and some of its challenges. Results: The application of this first approach on different software systems categories is presented with its summary evaluation. The richness and expressiveness of the concepts introduced by bio-inspired methodologies are strong compared with the conventional ones. However, the evaluation on real industrial software scale remains an open challenge. Conclusion: The obtained results prove the power, the effectiveness and simplicity of the bio-inspired methodologies compared to the conventional ones. The conventional software engineering is not inspired from nature processes and therefore, there is a gap between his concepts and mechanisms and those of real world. This leads to complexity and poverty in its models and their applications. However, this is the strength of the bio-inspired software engineering.

Keywords: Software engineering, bi-inspired software engineering

Research Title: OFDM Systems Performance Enhancement

Author: Qadri Jamal Al-Hamarsheh, Published Year: 2015

IEEE SSD'15, 12th International Multi-Conference on Systems, Signals & Devices, Mahdia, Tunisia

Faculty: Engineering and Technology

Abstract: in this work a comparison among different proposed algorithms has been done to check the performance improvements for current wireless technologies. Orthogonal Frequency Division Multiplexing (OFDM) technique is one of the main techniques that are uses to enhance the quality of service (QoS) for beyond third generation (B3G) systems. This is in order to meet the rapidly increased of multimedia users demand. This comparison includes three previous propositions that were made to enhance the OFDM performance; work based on linear coding techniques, work based on wavelet transform and work based on PWM. All these propositions have been made to combat the effect of high Peak-to-Average Power Ratio (PAPR).

Keywords: OFDM, PAPR, wavelet, linear coding, PWM.

Research Title: Enhancing the Odd Peaks Detection in OFDM Systems Using Wavelet Transforms

Author: Qadri Jamal Al-Hamarsheh, Published Year: 2016

International Journal of Communications, Network and System Sciences, vol. 9, no. 7

Faculty: Engineering and Technology

Abstract: This work aims to study the effect of unwanted peaks and enhance the performance of wireless systems on the basis of tackling such peaks. A new proposition has been made based on wavelet transform method and its entropy. Signals with large peak-to-average power ratio (PAPR) will be examined such as the ones that are considered as the major Orthogonal Frequency Division Multiplexing (OFDM) systems drawbacks. Furthermore, aspatial diversity Multiple-Input Multiple- Out-put (MIMO) technology is used to overcome the complexity addition that could arise in our proposition. To draw the best performance of this work, a MATLAB simulation has been used; it is divided into three main stages, namely, MIMO-OFDM symbols’ reconstruction based on wavelet transform, a predetermined thresholding formula, and finally, moving filter. This algorithm is called Peaks’ detection based Entropy Wavelet Transform; PD-EWT. Based on the simulation, and under some constrains such as the bandwidth occupancy and the complexity structure of the transceivers, a peak detection ratio has been achieved and reaches around 0.85. Comparing with our previously published works, the PD-EWT enhances detection ratio for 0.25 more peaks.

Keywords: Wavelet Transform, Entropy, MIMO, OFDM, PAPR

Research Title: Enhancing the Performance of OFDM Systems-Based PAPR Reduction

Author: Qadri Jamal Al-Hamarsheh, Published Year: 2016

International Journal of Circuits, Systems and Signal Processing, vol. 10, pp. 333-8

Faculty: Engineering and Technology

Abstract: In this work a comparison has been made among different proposed algorithms in order to improve the performance of a power consumption wireless network. They are used to combat one of the Orthogonal Frequency Division Multiplexing (OFDM) technique drawbacks, which are considered as a key technique in enhancing the new era of wireless systems’ quality of service (QoS). Therefore, three different propositions have been investigated and covered by this work and classified as; linear coding based, wavelet transformation based, PWM based. Furthermore, a MATLAB program has been run to check their performance and covers two different criteria; the curves of CCDF and the SER curves. This is in order to reduce the Peak-to-Average Power Ratio (PAPR) effect

Keywords: OFDM, PAPR, Linear Coding, Wavelet, PWM