Research Title: Investigating the Maximum Instantaneous Fault Current in Power Systems with High Penetration of Type-4 Wind

Author: Wasseem Hani Al Rousan, Published Year: 2023

2023 IEEE IAS Global Conference on Emerging Technologies (GlobConET), London, United Kingdom

Faculty: Engineering and Technology

Abstract: The increased attention towards Renewable Energy Sources (RESs), such as wind generation, has become a priority for systems operators and policymakers worldwide. Type-4 wind generators are considered one of the most common types of wind for large-scale integration of RESs. Type-4 wind generators employ converters for their interface to the AC grid. In such generators, the power exchange with the grid is fully controlled by the converter interface that utilizes power electronic switches of limited current-carrying capability during normal and faulty conditions. Hence, type-4 wind generators have different and limited fault current contributions compared to the traditional conventional generation units based on Synchronous Generators (SGs). In future scenarios where such RESs are extensively integrated, and the SGs are also decommissioned, the SC current behavior of the systems would be affected significantly, and a fault level reduction would be witnessed too. The maximum instantaneous SC current is one of the key SC current components that should be monitored in such scenarios due to its importance for several applications such as faults detection, proper settings of the protection settings, and the design of circuit breakers …etc. This paper is aimed at investigating the effect of the increased penetration of type-4 wind generation on the maximum instantaneous fault current in power grids with the increased penetration of type-4 wind RESs. The results and findings of this research are tested on the IEEE 9-Bus test system modeled in Matlab.

Keywords: instantaneous fault current, artificial neural network, type-4 wind generation, renewable energy

Research Title: Power Systems Cascading Failure Analysis and Mitigation Using Discrete Events Systems Approach

Author: Wasseem Hani Al Rousan, Published Year: 2022

Faculty: Engineering and Technology

Abstract: A power system cascading failure can propagate through sequential tripping of components in the network. As a result, a complete or partial shutdown may occur. Many models were developed to understand the failure propagation mechanism at a higher abstract level and methods were implemented for failure mitigation. This work introduces a unified framework of modeling and mitigating cascading failures. Based on a Discrete Event Systems (DES) approach, a power system is modeled by an automaton via parallel composition of the sub-models of system components. A modified DES supervisory control (SC) strategy is introduced as a solution to mitigating cascading failures and compared with a regular off-line control. The proposed supervisory control strategy is then extended to an on-line based control called limited lookahead policy (LLP) to overcome the increased complexity of large scale systems. An evaluation method and a criterion for assessing cascading failure risk and identifying critical components during failure propagation in the DES framework are then proposed. The proposed on-line control was implemented and verified through joint simulations between continuous time power flow analysis and discrete events dynamics with supervisory control. An illustrative example of the proposed approach is presented. Simulation studies for the on-line approach are carried out for IEEE 6-bus, 30-bus, and 118-bus systems to verify the effectiveness of the proposed approach. Modular supervisory control is also introduced to mitigate cascading failure for large scale power systems. A framework to implement modular control approach is then proposed. Similar to the on-line LLP approach, simulations based on case studies for the IEEE 6-bus and 30-bus systems are carried out to illustrate the effectiveness of the proposed approach.

Keywords: Cascading failure, discrete-event systems, Supervisory control

Research Title: Short-Term Load Forecasting Based on NARX and Radial Basis Neural Networks Approaches for the Jordanian Power Grid

Author: Wasseem Hani Al Rousan, Published Year: 2016

Jordan Journal of Electrical Engineering, ISSN (Online): 2409‐9619, Volume 2, Number 1

Faculty: Engineering and Technology

Abstract: This paper presents two techniques for short-term load forecasting (STLF) based on Artificial Neural Networks method (ANN). These techniques are the nonlinear auto regressive with external input (NARX) and radial basis function (RBF). The results from both methods are compared in order to attain minimum percentage errors. Input data implies weather factors that are the temperature and humidity. A comparison between the two techniques shows that RBF method has a better performance over NARX method in short periods training whereas NARX has the advantage in long periods training. The comparison between hourly actual and forecasted load readings shows a reasonable normalized mean square error (NMSE) with minimum values in summer: 3.9% for NARX and 3.5% for RBF, and in winter: 3.5% for NARX and 3.47% for RBF. Results show that minimum error is achieved by using five training days for summer and nine days for winter.

Keywords: ANN, Jordan, NARX, STLF

Research Title: Optimization of Induction Motor Equivalent Circuit Parameter Estimation Based on Manufacturer’s Data

Author: Wasseem Hani Al Rousan, Published Year: 2018

Energies, Volume 11, Issue 7

Faculty: Engineering and Technology

Abstract: This paper presents a two-stage optimization of the parameters of a seven-parameter equivalent circuit of three-phase induction motor. The initial parameters of this equivalent circuit are estimated by a method called the Engineering Method using the data given in the manufacturer’s data sheet. The two-stage parameter optimization procedure was developed to minimize the errors between the estimated and the actual values in motor torque and current. In the first stage, the method is targeted to optimize the parameters of the stator only. The second stage, if necessary, aims at optimizing the rotor-circuit parameters. Normalized least squares method is used to formulate the optimization problem. An objective function is established to minimize the errors between the calculated starting torque and current and the pullout torque and the given values in the manufacturer’s data sheet. The model parameters of ten industrial induction motors are estimated without and with optimization. The obtained results are compared with the Engineering Method and the actual manufacturer’s data to verify the effectiveness of the proposed method.

Keywords: equivalent circuit; induction motor; manufacturer’s data; optimization; parameters estimation; squirrel cage

Research Title: A Discrete Event Theory Based Approach for Modeling Power System Cascading Failures

Author: Wasseem Hani Al Rousan, Published Year: 2019

2019 IEEE Power & Energy Society General Meeting (PESGM), Atlanta, Georgia, USA

Faculty: Engineering and Technology

Abstract: For a power system cascading failure, the failure propagates through a sequential tripping of the components in the network. As a result, a complete or partial shutdown may occur. Although many models were developed to understand the failure propagation mechanism, the joint dynamics between discrete sequential tripping and continuous power flow has not been fully evaluated. Further study is needed in this area to develop an abstract higher model, which captures the systems flow dynamics. This paper introduces a new approach for studying the cascading failure and develops a model that translates the power system into an Automata based on the components operational modes. Based on a Discrete Event Systems (DES) approach, the overall system is analyzed. Cascading failure is then defined in a DES framework, and supervisory control strategies are introduced as a solution to mitigate cascading failures. Additionally, an illustrative example for the proposed approach is presented. Finally, the proposed modeling approach is simulated by combining continuous power flow study and DES tools in a unified framework.

Keywords: Cascading failure, discrete-event systems, hybrid simulation

Research Title: A Discrete-Event System Approach for Modeling and Mitigating Power System Cascading Failures

Author: Wasseem Hani Al Rousan, Published Year: 2022

IEEE Transactions on Control Systems Technology, Volume: 30, Issue: 6

Faculty: Engineering and Technology

Abstract: A power system cascading failure can propagate through sequential tripping of components in the network. As a result, a complete or partial shutdown may occur. In this article, we develop a new systematic approach to identify and prevent cascading failures in power systems using supervisory control of discrete-event systems (DESs). We build the DES model for a power system in a modular fashion by first modeling its components as (small) automata and then combining these automata using parallel composition. To overcome state explosion, we use online lookahead control that can significantly reduce the number of states to be considered. Since some events such as line trips cannot be disabled but can be preempted by forcing some forcible events such as load shedding, we extend supervisory control of DES to include forcible events. This extension allows us to control power systems effectively. The proposed control is implemented in an implementation platform that we build in MATLAB. The platform uses MATPOWER to simulate a power system and then control it using the proposed DES controller. Simulation studies are carried out for IEEE 6-, 30-, and 118-bus systems. The results verify the effectiveness of the proposed approach.

Keywords: Power system protection, Power system faults, Power systems, Supervisory control, Hybrid power systems, Discrete-event systems

Research Title: Application of Passive Harmonic Filters in Power Distribution System with High Share of PV Systems and Non-Linear Loads

Author: Wasseem Hani Al Rousan, Published Year: 2023

International Journal of Renewable Energy Research-IJRER, Vol 13, No 1

Faculty: Engineering and Technology

Abstract: The increasing demand of non-linear loads and the revolution towards renewable energy sources connected at the utility scale, would potentially increase harmonic distortion in power distribution networks. Therefore, mitigation measures should be considered to deal with high levels of harmonics. Traditionally, a combination of passive filters has been used as an effective solution. However, the efficacy of such solution has not been investigated thoroughly in networks with high share of renewable energy sources, such as PVs. This paper analyzes harmonic distortions caused by distributed generators (PV) and non-linear loads connected to the 480 V distribution feeder. It aims to model and implement a collection of single-tuned passive filters to mitigate the harmonic levels and improve the power factor. The results have demonstrated the efficacy of the proposed collection of single-tuned passive filters in mitigating the harmonic levels and improve the power factor with high share of PV systems (i.e., 59% PV penetration scenario).They have shown that, when designed and tuned properly, single-tuned harmonic filters can significantly reduce the 5th, 7th, and the 11th current harmonic distortions from 22.71%, 12.5%, and 6.102?fore applying the filter down to 0.04199%, 0.1956%, and 0.1056%, respectively. The findings have been verified using a distribution feeder on MATLAB Simulink.

Keywords: Distributed Generators, Distribution Systems, Harmonic Filters, Power Quality, PV systems, Total harmonic distortion

Research Title: Development and Characterization of Gel-Based Buccoadhesive Bilayer Formulation of Nifedipine

Author: Balakumar Chandrasekarn, Published Year: 2023

GELS, 9

Faculty: Pharmacy

Abstract: A promising controlled drug delivery system has been developed based on polymeric buccoadhesive bilayered formulation that uses a drug-free backing layer and a polymeric hydrophilic gel buccoadhesive core layer containing nifedipine. The DSC thermogravimetric analysis confirms the drug’s entrapment in the gel layer and reveals no evidence of a potential interaction. Various ratios of bioadhesive polymers, including HPMC K100, PVP K30, SCMC, and CP 934, were combined with EC as an impermeable backing layer to ensure unidirectional drug release towards the buccal mucosa. The polymeric compositions of hydrophilic gel-natured HPMC, SCMC, and CP formed a matrix layer by surrounding the core nifedipine during compression. Preformulation studies were performed for all of the ingredients in order to evaluate their physical and flow characteristics. Ex vivo buccoadhesive strength, surface pH, swelling index, in vitro and in vivo drug release, and ex vivo permeation investigations were performed to evaluate the produced gel-based system. Rapid temperature variations had no appreciable impact on the substance’s physical properties, pharmacological content, or buccoadhesive strength during stability testing using actual human saliva. It was clear from a histological examination of the ex vivo mucosa that the developed system did not cause any irritation or inflammation at the site of administration. The formulation NT5 was the best one, with a correlation coefficient of 0.9966. The in vitro and in vivo drug release profiles were well correlated, and they mimic the in vitro drug release pattern via the biological membrane. Thus, the developed gel-based formulation was found to be novel, stable, and useful for the targeted delivery of nifedipine.

Keywords: buccoadhesive; triggered delivery; ex vivo permeation; polymeric gel

Research Title: Combating Microbial Infections Using Metal-Based Nanoparticles as Potential Therapeutic Alternatives

Author: Balakumar Chandrasekarn, Published Year: 2023

Antibiotics, 12

Faculty: Pharmacy

Abstract: The nature of microorganisms and the efficiency of antimicrobials have witnessed a huge co-dependent change in their dynamics over the last few decades. On the other side, metals and metallic compounds have gained popularity owing to their effectiveness against various microbial strains. A structured search of both research and review papers was conducted via different electronic databases, such as PubMed, Bentham, Springer, and Science Direct, among others, for the present review. Along with these, marketed products, patents, and Clinicaltrials.gov were also referred to for our review. Different microbes such as bacteria, fungi, etc., and their diverse species and strains have been reviewed and found to be sensitive to metal-carrying formulations. The products are observed to restrict growth, multiplication, and biofilm formation effectively and adequately. Silver has an apt use in this area of treatment and recovery, and other metals like copper, gold, iron, and gallium have also been observed to generate antimicrobial activity. The present review identified membrane disruption, oxidative stress, and interaction with proteins and enzymes to be the primary microbicidal processes. Elaborating the action, nanoparticles and nanosystems are shown to work in our favor in well excelled and rational ways.

Keywords: metals; nanoparticles; antimicrobial action; microbicidal; biofilm formation inhibitors

Research Title: Novel fluorophenyl tethered thiazole and chalcone analogues as potential anti-tubercular agents: Design, synthesis, biological and in silico evaluations

Author: Balakumar Chandrasekarn, Published Year: 2023

Journal of Molecular Structure, 1276

Faculty: Pharmacy

Abstract: Novel analogues of fluorophenyl tethered thiazoles 7a-k and chalcones 10a-k were designed through molecular hybridization approach. All the synthesized final compounds were evaluated for their in vitro antimycobacterial activity against M. tuberculosis H37Rv strain. Among the two series, compound 10g displayed potent inhibition with MIC99 of 1.56 µM against parental and isoniazid-resistant strains of M. tuberculosis. Further, the same compound inhibited the growth of intracellular M. tuberculosis. To gain an insight into the molecular mechanism of actions, in silico molecular docking experiments were conducted using the molecular structure of the DNA gyrase enzyme, which revealed crucial interactions. This was further substantiated through molecular dynamics simulation study of the mycobacterial DNA Gyrase protein against the lead compound 10g and the reference drug (CFX-Ciprofloxacin). Furthermore, the drug-likeliness of the synthesized compounds was computed based on Lipinski's rule of five and ADME pharmacokinetic parameters.

Keywords: Fluorophenyl-thiazoleChalconeMolecular dockingMolecular dynamicsADME properties