Electrical and Electronics Engineering Technology

Objective: Home surveillance monitoring might identify patients at risk for interstage death after stage 1 palliation for hypoplastic left heart syndrome. We sought to identify the effect that a high-risk program might have on interstage mortality and identification of residual/recurrent lesions after neonatal palliative operations. Methods: Between January 2006 to January 2010, newborns after stage 1 palliation for hypoplastic left heart syndrome or shunt placement were invited to participate in our high-risk program. Patients enrolled in our high-risk program comprise the study group. Patients who had similar operations between January 2002 and December 2005 comprise the control group. Comparisons are made between the 2 groups with respect to interstage mortality and the frequency and timing of interstage admissions requiring medical, catheter, or surgical treatment. Results: Seventy-two patients met the criteria for our high-risk program. Fifty-nine (82%) of 72 patients were enrolled. Among 19 patients with hypoplastic left heart syndrome in our high-risk program, outpatient interstage mortality was zero. Outpatient interstage mortality for the 36 control subjects with hypoplastic left heart syndrome was 6%. Among 40 patients with shunts in the study group, there was 1 outpatient interstage death compared with 4 (6%) deaths in 68 subjects in the control group. Significant residual/recurrent lesions were identified with similar frequency between the 2 groups. However, after shunt operations, these lesions were detected and treated at significantly younger mean ages for patients followed in the high-risk program (P<.005). Conclusions: Initiation of a high-risk program might decrease interstage mortality after high-risk neonatal palliative operations. Such an approach might contribute to earlier detection of significant residual/recurrent lesions amenable to therapy.

A novel and non-invasive pulsed electric field (PEF) technology for use in the food processing industry is under development at both Loughborough University (UK) and the University of Pau (France). The technology uses an antenna coupled to a high-voltage pulsed generator to produce short duration pulses of very intense electric field strength. In the Loughborough scheme, a Tesla transformer charges an oil-filled pulse forming line to more than 500 kV, and electric fields are generated by a pulsed antenna with a rise time of 1 ns with a figure of merit of about 130 kV. In the Pau scheme, a gas pressurised pulse forming unit, comprising a peaking stage and a crowbar switch, is incorporated into the last stage of a ten-stage Marx generator. When a Valentine travelling wave antenna is attached, the overall system is capable of generating electric fields with a rise time of 300 ps with a figure of merit of 450 kV. During the common research programme, the combination of a Tesla transform...

This paper proposes an efficient control strategy to enhance frequency stability of three-area power system considering a high penetration level of wind energy. The proposed strategy is based on a combination of a Proportional Integral Derivative (PID) controller with a Linear Quadratic Gaussian (LQG) approach. The parameters of the proposed controller (i.e., PID-LQG) are optimally designed by a novel natural physical based-algorithm called Lightning Attachment Procedure Optimization (LAPO). The main objective is to keep the frequency fluctuation at its acceptable value in the presence of high penetration of wind energy, high load disturbance and system uncertainties. The superiority of the proposed PID-LQG controller is validated by comparing its performance with optimal Coefficient Diagram Method (CDM) controller, conventional CDM controller, optimal PID controller-based LAPO, and integral controller. Moreover, the exhaustive results completely demonstrate that the proposed controller gives better performance in terms of overshoot, undershoot, and settling time as well as provides reliable frequency stability for interconnected power systems considering high wind penetration and system uncertainties. INDEX TERMS Frequency stability, interconnected power systems, linear quadratic Gaussian (LQG), lightning attachment procedure optimization (LAPO), high penetration of wind energy. MOHAMED KHAMIES received the B.Sc. and M.Sc. degrees (Hons.) in electrical engineering from Aswan University, Egypt, in 2011 and 2014, respectively, where he is currently pursuing the Ph.D. degree in electrical engineering. Since 2013, he has been an Electrical Engineer with the Ministry of Electricity and Renewable Energy, Egypt. His research interests include power system stability, and control, smart/micro-grid control, renewable energies, and energy storage systems. GABER MAGDY received the B.Sc. and M.Sc. degrees (Hons.

Recently, two essential milestones have been very successfully achieved in a joint research programme in progress at Loughborough University (UK) and Université de Pau (France) aimed to develop a novel non-invasive PEF technology for the processing industrial food. These are the reliable measurement of the intense fast transient electric fields generated in water close to electrodes and a convincing proof demonstration of the non-invasive technique. The paper presents results from preliminary experiments with a non of-principle treatment chamber, highlighting the paramount importance of electro-optic Kerr measurements. In addition, very successful proof-of-principle non-invasive processing experiments will be discussed, in which the electric field in the samples was continuously monitored using the Kerr effect and a 6 reduction was obtained in the Escherichia coli initially present. During the non-invasive tests only displacement currents, of the order of a few tens of mA, were flowing inside the water samples in contrast with (at least) the kA current usually produced through the liquid samples treated using invasive PEF technology. The implication of the 105 difference in the current is obvious: the energy consumption by Joule effect in PEF is practically null, a very important fact in industrial applications Keywords -

This paper proposes an efficient control strategy to enhance frequency stability of three-area power system considering a high penetration level of wind energy. The proposed strategy is based on a combination of a Proportional Integral Derivative (PID) controller with a Linear Quadratic Gaussian (LQG) approach. The parameters of the proposed controller (i.e., PID-LQG) are optimally designed by a novel natural physical based-algorithm called Lightning Attachment Procedure Optimization (LAPO). The main objective is to keep the frequency fluctuation at its acceptable value in the presence of high penetration of wind energy, high load disturbance and system uncertainties. The superiority of the proposed PID-LQG controller is validated by comparing its performance with optimal Coefficient Diagram Method (CDM) controller, conventional CDM controller, optimal PID controller-based LAPO, and integral controller. Moreover, the exhaustive results completely demonstrate that the proposed controller gives better performance in terms of overshoot, undershoot, and settling time as well as provides reliable frequency stability for interconnected power systems considering high wind penetration and system uncertainties. INDEX TERMS Frequency stability, interconnected power systems, linear quadratic Gaussian (LQG), lightning attachment procedure optimization (LAPO), high penetration of wind energy. MOHAMED KHAMIES received the B.Sc. and M.Sc. degrees (Hons.) in electrical engineering from Aswan University, Egypt, in 2011 and 2014, respectively, where he is currently pursuing the Ph.D. degree in electrical engineering. Since 2013, he has been an Electrical Engineer with the Ministry of Electricity and Renewable Energy, Egypt. His research interests include power system stability, and control, smart/micro-grid control, renewable energies, and energy storage systems. GABER MAGDY received the B.Sc. and M.Sc. degrees (Hons.

Induction motors are still the most used in industrial applications due to the simplicity of installation and low maintenance cost, especially for the squirrel cage type. The significant development in power electronics in terms of highspeed technologies in power electronic switches, their availability in high ratings, and the considerable decrease in the cost of the power electronics components supports this increase in uses. However, changing the induction motor's speed with loading, load torque measurement devices, and speed sensors limit this increase in using such motors. This paper proposes a state feedback controllerbased backstepping technique for robust speed regulators of induction motor loaded without measuring the load torque. Designing such a controller (state feedback controller) needs to know the value of the load torque, and hence torque values are assumed to start the design process. A state observer as output feedback is integrated into the speed controller proposed in this paper instead of load torque measurement. To asset the proposed controller's capability to keep the induction motor speed at the desired value, the global stability is investigated using Lyapunov direct theorem. The simulation results show that the proposed method's effectiveness in keeping the motor speed at the desired value without load torque measurement.

Recently, extracting the precise values of unknown parameters of the polymer electrolyte membrane fuel cell (PEMFC) is considered one of the most widely nonlinear and semi-empirical optimization problems. This paper proposes and applies a Modified Artificial Ecosystem Optimization (MAEO) algorithm to solve the problem of PEMFC parameters extraction. The conventional AEO is a novel optimization technique that is inspired by the energy flow in a natural ecosystem which is defined as abiotic, which includes non-living bodies and elements such as light, water and air. The proposed optimization algorithm, MAEO, is used to enhance the performance of conventional AEO and provide faster convergence rate as well as to be far away from falling into the local optima. In the proposed MAEO, an operator is suggested to improve the balance between exploitation and Exploration phases. The accurate estimation of PEMFC unknown parameters leads to develop a precise mathematical model which simulates the electrochemical and electrical characteristics of PEMFC. The objective function of the studied optimization problem is formulated as the sum of squared errors (SSE) between the measured and simulated stack voltages. To prove the reliability and capability of the proposed MAEO algorithm in solving this problem compared with other recent algorithms, it is tested on four different PEMFC stack models, namely, BCS-500W, SR-12 500W, 250W and Temasek 1 kW stacks. Moreover, statistical measures are performed to assess the superiority and robustness of the proposed algorithm. In addition, the accuracy of optimized parameters is assessed through the dynamic characteristics of PEMFCs under varying the reactants' pressures and temperature of the cell. However, the simulation results confirm that the proposed MAEO algorithm has high accuracy and reliability in extracting the PEMFC optimal parameters compared with the conventional AEO and other effective algorithms. INDEX TERMS Polymer electrolyte membrane fuel cell, parameters extraction, modified artificial ecosystem optimization, sum of squared errors, polarization curves.

The use of models, frameworks, and toolkits in learning design serve to support teaching practitioners in producing well-structured learning designs for students. However, existing learning design tools inherently lack an objective metric system which is able to measure the degree to which an educational design is well-formed according to either the principles of constructive alignment or more generally design practices that students find satisfactory in practice. Such a metric system, that could integrate measures of educational theory and practice, would enable teaching practitioners to make more informed design decisions such as which profile of activities/assessments to use for a particular set of learning outcomes. This paper presents the first computational intelligence tool that measures educational design quality in a way that is underpinned by both the theoretical principles of constructive alignment and how it is used in practice. Furthermore, the alignment metrics computed are calibrated by student satisfaction scores to promote those structures that are preferred in practice rather than from a theoretical standpoint thus offering more pragmatic and realistic design solutions.

This paper is devoted to a detailed presentation of all aspects involved in a demonstration of a novel pulsed electric field technique that does not generate conduction currents or Joule effects. Details are given of both the experimental arrangement and the electro-optic Kerr-effect based diagnostic used in the measurement of the intense pulsed electric fields in water. The results show unequivocally that the novel technique is effective in significantly reducing the initial concentration of Escherichia coli bacteria. Finally, a brief comment on the way ahead is provided.

This paper presents an adaptive protection scheme (APS) for solving the coordination problem that deals with coordination directional overcurrent relays (DOCRs) and distance relays second zone time, in relation to coordination with DOCRs. The coordination problem becomes more complex with the impact of renewable energy sources (RES) when added to the distribution grid. This leads to a change in the grid topology, caused by the on/off states of the distribution generators (DG). The frequency of topological changes in distribution grids poses a challenge to the power system’s protection components. The change in the state of DGs leads to malfunction in reliability and miscoordination between protection relays, since that causes a direct effect to the short circuit currents. This paper used the school-based optimization (SBO) algorithm, which simulates the educational process, in order to deal with coordination problems. That algorithm is modified (MSBO) by modified both learning and t...

The superplastic forming process is used in a wide range of high-value-added manufacturing sectors to make lightweight, complex-shaped components for high-performance applications. Currently, it is a high-cost process, for example, the superplastic forming of titanium alloys involves a high-temperature furnace, costly (mould) tooling and has a high utilization of resources such as argon gas and energy. The authors of this article propose a prototype for next-generation superplastic forming laboratory equipment. The aim is to develop improved methods, particularly for heat management in the superplastic forming process, to allow a more widespread application of the process to manufacture lower cost products. The next-generation superplastic forming tool comprises a tool in the form of a hemispherical shell, pressure chamber with incorporated water cooling system and an infrared heating system. The construction, usability and suitability of the next-generation superplastic forming equ...

The use of models, frameworks, and toolkits in learning design serve to support teaching practitioners in producing well-structured learning designs for students. However, existing learning design tools inherently lack an objective metric system which is able to measure the degree to which an educational design is well-formed according to either the principles of constructive alignment or more generally design practices that students find satisfactory in practice. Such a metric system, that could integrate measures of educational theory and practice, would enable teaching practitioners to make more informed design decisions such as which profile of activities/assessments to use for a particular set of learning outcomes. This paper presents the first computational intelligence tool that measures educational design quality in a way that is underpinned by both the theoretical principles of constructive alignment and how it is used in practice. Furthermore, the alignment metrics computed are calibrated by student satisfaction scores to promote those structures that are preferred in practice rather than from a theoretical standpoint thus offering more pragmatic and realistic design solutions.

Solar photovoltaic (PV) energy has met great attention in the electrical power generation field for its many advantages in both on and off-grid applications. The requirement for higher proficiency from the PV system to reap the energy requires maximum power point tracking techniques (MPPT). This paper presents an adaptive MPPT of a stand-alone PV system using an updated PI controller optimized by harmony search (HS). A lookup table is formed for the temperature and irradiance with the corresponding voltage at MPP (VMPP). This voltage is considered as the updated reference voltage required for MPP at each temperature and irradiance. The difference between this updated reference voltage at MPP and the variable PV voltage due to changing the environmental conditions is used to stimulate PI controller optimized by HS to update the duty cycle (D) of the DC–DC converter. The temperature, irradiance, and corresponding duty cycle at MPP are utilized to convert this MPP technique into an ada...

Frequency Response Analysis (FRA) is the most reliable technique currently used to evaluate the mechanical integrity of power transformers. While the measurement devices have been well developed over the past two decades, interpretation of the FRA signatures is still challenging regardless of the several papers published in this regard. This paper adds an attempt to understand the power transformer FRA signatures through experimental and simulation analyses. In this context, experimental FRA measurements are conducted on a 33/11 kV, 30 MVA transformer under various faults, including winding deformation, the short circuit turns, loss of clamping, and bushing fault. At the same time, the high-frequency transformer model that comprises series capacitance, self-inductance, series resistance, and mutual inductance is simulated using MATLAB / Simulink to compare simulation and experimental results. The correlation between physical circuit parameters and various faults facilitates a better understanding of each fault's effect on the FRA signature. To quantify the impact of such faults, correlation coefficient, the absolute sum of logarithmic error, standard deviation, and sum square error are calculated with respect to the healthy signature at three frequency regions. Results show that using statistical coefficients over three frequency ranges of the FRA signature facilitates better fault identification and quantification. INDEX TERMS Power transformer, frequency response analysis, fault diagnosis, statistical indicators. NOMENCLATURE V in , V out Injected and measured voltage R in , R out Input and output Resistance R s Series resistance C s Series capacitance C t Capacitance between turns C d Capacitance between discs C g Capacitance to ground The associate editor coordinating the review of this manuscript and approving it for publication was Dazhong Ma. L s Series inductance C sHV , C sLV Series capacitance in HV and LV G s Series Conductance C gHV , C gLV Capacitance to the ground in HV, and LV winding C HL Capacitance between the HV winding and LV winding G HL Conductance between the HV winding and LV winding M km Mutual inductance

In order to address power flow control issues, this study introduces the use of Unified Power Flow Controller (UPFC) models. These models are based on regulating the variables influencing the transmission line’s power flow, and they are capable of controlling the bus voltage, the line’s actual and reactive power, all at once and independently. The idea behind the UPFC technique proposed in this paper is to provide the unique functional capability of independently controlling both the real and reactive power flow in the line. The in-phase component of the series injected voltage dominates the reactive power while the quadrature component affects the real power. A conventional controlling steady-state analysis and dynamic stability analysis of the power system is developed based on the UPFC model. UPFC provides real-time controlling of all or any combination of the power system parameters which determine the transmittable power. UPFC can force and maintain strategically chosen values ...