Comparative Study of the Types of Photovoltaic Panels Used in Solar Pumping Systems in Dry Tropical Zones: Case of Adamawa Region in Cameroon

In the dry tropical zone where access to water is increasingly difficult for populations, solar pumping units are increasingly installed to provide water to population. In the local market, there are essentially two types of solar panels, namely monocrystalline and polycrystalline. However, the part of the local market is more dominated by the polycrystalline panel. In this work, comparative studies are carried out in order to characterize the two types of solar panels with regard to local constraints. Tests were carried out over the course of the sun to establish the performance of each type. The panels used have the same electrical characteristics and are connected to loads with same characteristics. Under the set operating conditions, the monocrystalline panel presents more performance than the polycrystalline panel. Although the local market is dominated by the polycrystalline panel, dust deposition tests on the surface of the panels show that the performance of the polycrystalline panel is more affected compared to the performance of the monocrystalline panel.

Design of hybrid damping controller based on multi-target gravitational search optimization algorithm in a multi-machine power system with high penetration of PV park

A mathematical approach was proposed to investigate the impact of high penetration of large-scale photovoltaic park(LPP) on small-signal stability of a power network and design of hybrid controller for these units.A systematic procedure was performed to obtain the complete model of a multi-machine power network including LPP.For damping of oscillations focusing on inter-area oscillatory modes,a hybrid controller for LPP was proposed.The performance of the suggested controller was tested using a 16-machine 5-area network.The results indicate that the proposed hybrid controller for LPP provides sufficient damping to the low-frequency modes of power system for a wide range of operating conditions.The method presented in this work effectively indentifies the impact of increased PV penetration and its controller on dynamic performance of multi-machine power network containing LPP.Simulation results demonstrate that the model presented can be used in designing of essential controllers for LPP.

Intelligent Networked Control of Vasoactive Drug Infusion for Patients with Uncertain Sensitivity

Abnormal high blood pressure or hypertension is still the leading risk factor for death and disability worldwide.This paper presents a new intelligent networked control of medical drug infusion system to regulate the mean arterial blood pressure for hypertensive patients with different health status conditions.The infusion of vasoactive drugs to patients endures various issues,such as variation of sensitivity and noise,which require effective and powerful systems to ensure robustness and good performance.The developed intelligent networked system is composed of a hybrid control scheme of interval type-2 fuzzy(IT2F)logic and teaching-learning-based optimization(TLBO)algorithm.This networked IT2F control is capable of managing the uncertain sensitivity of the patient to anti-hypertensive drugs successfully.To avoid the manual selection of control parameter values,the TLBO algorithm is mainly used to automatically find the best parameter values of the networked IT2F controller.The simulation results showed that the optimized networked IT2F achieved a good performance under external disturbances.A comparative study has also been conducted to emphasize the outperformance of the developed controller against traditional PID and type-1 fuzzy controllers.Moreover,the comparative evaluation demonstrated that the performance of the developed networked IT2F controller is superior to other control strategies in previous studies to handle unknown patients’sensitivity to infused vasoactive drugs in a noisy environment.

Model Identification of a Micro Air Vehicle

This paper is focused on the model identification of a Micro Air Vehicle （MAV） in straight steady flight condition. The identification is based on input-output data collected from flight tests using both frequency and time dorrtain techniques. The vehicle is an in-house 40 cm wingspan airplane. Because of the complex coupled, multivariable and nonlinear dynamics of the aircraft, linear SISO structures for both the lateral and longitudinal models around a reference state were derived. The aim of the identification is to provide models that can be used in future development of control techniques for the MAV.

Fault Ride-Through Capability of Full-Power Converter Wind Turbine

In order to ensure power system stability, modern wind turbines are required to be able to endure deep voltage dips. The specifications that determine the voltage dip versus time are called fault r/de-through （FRT） requirements. The purpose of this paper is not only to examine the FRT behavior of a full-power converter wind turbine but also to combine the power system viewpoint to the studies. It is not enough for the turbine to be FRT capable; the loss of mains （LOM） protection of the turbine must also be set to allow the FRT. Enabling FRT, however, means that the LOM protection settings must be loosen, which may sometimes pose a safety hazard. This article introduces unique real-time simulation environment and proposes an FRT method for a wind turbine that also takes the operation of LOM protection relay into account. Simulations are carried out using the simulation environment and results show that wind turbine is able to ride-through a symmetrical power system fault.

The Effect of Surface Pit Treatment on Fretting Fatigue Crack Initiation

This paper analyses the effect of surface treatment on fretting fatigue specimen by numerical simulations using Finite Element Analysis.The processed specimen refers to artificially adding a cylindrical pit to its contact surface.Then,the contact radius between the pad and the specimen is controlled by adjusting the radius of the pit.The stress distribution and slip amplitude of the contact surface under different contact geometries are compared.The critical plane approach is used to predict the crack initiation life and to evaluate the effect of processed specimen on its fretting fatigue performance.Both crack initiation life and angle can be predicted by the critical plane approach.Ruiz parameter is used to consider the effect of contact slip.It is shown that the crack initial position is dependent on the tensile stress.For same type of model,three kinds of critical plane parameters and Ruiz method provide very similar position of crack initiation.Moreover,the improved sample is much safer than the flat-specimen.

Notice of Post-Publication Acknowledgement

The research work in Ref.[1]received support from the Surgical Center Henri Mondor, University Paris 12,France.Therefore,we would like to publish the following acknowledgement:This work was within the framework of an Erasmus student mobility at the Higher Institute of Bio Science,University Paris 1 2,France,which enabled the international collaboration with Faculty of Medical Bioengineering,University ofIasi,Romania.The experimental measurements and partial processing ofthe data presented in this article

A Novel Device for Real-Time Monitoring of High Frequency Phenomena in CENELEC PLC Band

This paper proposes the design and development of a novel, portable and low-cost intelligent electronic device (IED) for real-time monitoring of high frequency phenomena in CENELEC PLC band. A high speed floating-point digital signal processor (DSP) along with 4 MSPS analog-to-digital converter (ADC) is used to develop the intelligent electronic device. An optimized algorithm to process the analog signal in real-time and to extract the meaningful result using signal processing techniques has been implemented on the device. A laboratory environment has setup with all the necessary equipment including the development of the load model to evaluate the performance of the IED. Smart meter and concentrator is also connected to the low voltage (LV) network to monitor the PLC communication using the IED. The device has been tested in the laboratory and it has produced very promising results for time domain as well as frequency domain analysis. Those results imply that the IED is fully capable of monitoring high frequency disturbances in CENELEC PLC band.

Stand-Alone Wind Power System Operating with Different Storage Structures

This paper deals with control method related to a wind system operating in stand-alone applications. The stand-alone wind system is composed of three energy transfer subsystems： wind generator subsystem （wind turbine and electrical generator）, energy storage subsystem, respectively, specific local network subsystem （controlled loads）. This wind power system performs in the same time the maximization of wind energy conversion and the power balance between produced and required power. Three structures of the energy storage subsystem, based on buffer battery operation and/or capacitor voltage control, are discussed. The simulation results show that the proposed stand-alone wind power system ensures a good management of the local energy request. The design of the structures is analyzed in Matlab/Simulink environment, using PowerSim toolbox.

Influence of DFIG Wind Turbine Protection and Control during Voltage Dip on Circuit Breaker Operation

This paper analyzes a DFIG （doubly fed induction generator） WT （wind turbine） fault current after a symmetrical network voltage dip. The goal is to identify the factors determining how fast the first zero crossings of the fault current occur. This is an important subject because the ftmdamental property of the CB （circuit breaker） is that it breaks the current when the current is very near zero. The study was conducted using a hardware-in-the-loop test environment constructed using two real time simulators （dSPACE and RTDS） and a commercial protection relay. It is found that the reactive current injection during a voltage dip demanded by the grid codes enhances the operation of the WT protection because the zero crossings of the currents through CB are attained earlier. In addition, the size of the crowbar resistance has a significant influence on the zero crossings.

Questionnaire Survey of Services and Outsourcing in Finnish Distribution Companies

The aim of this study was to find out what types of services Finnish distribution companies were purchasing and what is the future trend related to them. Results were gathered from Finnish distribution companies using questionnaire. Theoretical background was collected from literacy to get more information of benefits and risks. Results indicate that purchasing services especially from independent service providers is increasing. Also the benefits are greater than the risks related to service purchasing.

Numerical Modeling of Sugarcane Bagasse Combustion in Sugar Mill Boiler

The sugarcane bagasse fuel is an energetic deposit opportunity for thermal and electricity generation in sugar society.Combustion behaviors,essential for effective operation of these devices are a necessity.A 3D numerical model has been developed in the commercial software Ansys Fluent.According to the fuel density and particle variable,this model took into account both suspension and grate model combustion.The realizable k-ε turbulent model with the P-1 model shows its advantage of describing such king problems and has been applied on the numerical model.The contour of the temperature,spices and the particle trajectory provided a clear understanding of bagasse fuel combustion in the furnace as well,bagasse particle goes through from initial heating to char combustion and its conversion to ash.The results obtained were in accordance with those of the literature.These results could be used to analyze this inexpensive combustion process for looking for the effect of design parameter change on the furnace performance.

Digital Twin-Based Automated Fault Diagnosis in Industrial IoT Applications

In recent years, Digital Twin (DT) has gained significant interestfrom academia and industry due to the advanced in information technology,communication systems, Artificial Intelligence (AI), Cloud Computing (CC),and Industrial Internet of Things (IIoT). The main concept of the DT isto provide a comprehensive tangible, and operational explanation of anyelement, asset, or system. However, it is an extremely dynamic taxonomydeveloping in complexity during the life cycle that produces a massive amountof engendered data and information. Likewise, with the development of AI,digital twins can be redefined and could be a crucial approach to aid theInternet of Things (IoT)-based DT applications for transferring the data andvalue onto the Internet with better decision-making. Therefore, this paperintroduces an efficient DT-based fault diagnosis model based on machinelearning (ML) tools. In this framework, the DT model of the machine isconstructed by creating the simulation model. In the proposed framework,the Genetic algorithm (GA) is used for the optimization task to improvethe classification accuracy. Furthermore, we evaluate the proposed faultdiagnosis framework using performance metrics such as precision, accuracy,F-measure, and recall. The proposed framework is comprehensively examinedusing the triplex pump fault diagnosis. The experimental results demonstratedthat the hybrid GA-ML method gives outstanding results compared to MLmethods like LogisticRegression (LR), Na飗e Bayes (NB), and SupportVectorMachine (SVM). The suggested framework achieves the highest accuracyof 95% for the employed hybrid GA-SVM. The proposed framework willeffectively help industrial operators make an appropriate decision concerningthe fault analysis for IIoT applications in the context of Industry 4.0.

Modelling Mechanical Properties in Native and Biomimetically Formed Vascular Grafts

The paper presents a detailed analysis of experimental data in order to characterize the elastic properties of arteries.Such analysis would provide a good basis for evaluation of biomimetic vascular grafts.Since the latter needs to exhibit similar properties of native tissue,it is important to accurately characterize the biomimetic sample in a large range of applied stresses. The stress-strain properties vary according to the specific pathology(e.g.arteriosclerosis,aneurism)and the tissue graft must be chosen correctly.Two models are proposed in this paper on the stress-strain characteristics.An extension for frequency-domain analysis is provided for one of the models.The comparison between vascular grafts and native tissue for carotid and thoracic arteries in pigs are in good agreement with results from literature.The proposed experimental method offers suitable parameters for identifying models which characterize both elasticity and stiffness properties of the analyzed tissues(stress-strain).The proposed models show good performance in characterizing the intrinsic material properties.

A Review on Fretting Wear Mechanisms,Models and Numerical Analyses

Fretting wear is a material damage in contact surfaces due to micro relative displacement between them.It causes some general problems in industrial applications,such as loosening of fasteners or sticking in components supposed to move relative to each other.Fretting wear is a complicated problem involving material properties of tribosystem and working conditions of them.Due to these various factors,researchers have studied the process of fretting wear by experiments and numerical modelling methods.This paper reviews recent literature on the numerical modelling method of fretting wear.After a briefly introduction on the mechanism of fretting wear,numerical models,which are critical issues for fretting wear modelling,are reviewed.The paper is concluded by highlighting possible research topics for future work.

Stabilization for Equal-Order Polygonal Finite Element Method for High Fluid Velocity and Pressure Gradient

This paper presents an adapted stabilisation method for the equal-order mixed scheme of finite elements on convex polygonal meshes to analyse the high velocity and pressure gradient of incompressible fluid flows that are governed by Stokes equations system.This technique is constructed by a local pressure projection which is extremely simple,yet effective,to eliminate the poor or even non-convergence as well as the instability of equal-order mixed polygonal technique.In this research,some numerical examples of incompressible Stokes fluid flow that is coded and programmed by MATLAB will be presented to examine the effectiveness of the proposed stabilised method.

电动汽车的建模与模拟——不同锂离子电池技术的实施(英文)

受限制的续航距离是锂离子电池电动汽车的缺点之一。特别是在低温下,由于低的电池容量、功率,以及辅助设备的附带能量需求,使得该续航距离又被减少。选用了一种基于模型的方法,来比较几种不同的电池技术的车内性能。设定了不同的试验情景,分析电池特性。模拟结果表明:由于电池容量的减少,限制了制动器能量的恢复,因此,在城市近郊及低温环境下,动力系的能量需求明显升高。此外,针对不同的温度、电池尺寸和驾驶周期,分析了电池和动力系的效率。最后,针对不同驾驶周期、温度和附加载荷,研究了电动续航距离。

Machine Learning-Enabled Power Scheduling in IoT-Based Smart Cities

Recent advancements in hardware and communication technologies have enabled worldwide interconnection using the internet of things(IoT).The IoT is the backbone of smart city applications such as smart grids and green energy management.In smart cities,the IoT devices are used for linking power,price,energy,and demand information for smart homes and home energy management(HEM)in the smart grids.In complex smart gridconnected systems,power scheduling and secure dispatch of information are the main research challenge.These challenges can be resolved through various machine learning techniques and data analytics.In this paper,we have proposed a particle swarm optimization based machine learning algorithm known as a collaborative execute-before-after dependency-based requirement,for the smart grid.The proposed collaborative execute-before-after dependencybased requirement algorithm works in two phases,analysis and assessment of the requirements of end-users and power distribution companies.In the rst phases,a xed load is adjusted over a period of 24 h,and in the second phase,a randomly produced population load for 90 days is evaluated using particle swarm optimization.The simulation results demonstrate that the proposed algorithm performed better in terms of percentage cost reduction,peak to average ratio,and power variance mean ratio than particle swarm optimization and inclined block rate.

Requirements and Proposed Solutions for Future Smart Distribution Substations

This paper proposes a novel solution for the secondary system of a primary distribution substation. First an evaluation is made of the changes that are to be expected for distribution substations in the future. Distributed generation, electric vehicles and other active resources will change the behavior of the distribution network in a manner that will have a great deal of implications for distribution substations. The question is how the role of the distribution substations will change when the visions of smart grids become reality. The proposed solution consists of bay level protection and control IEDs forming the backbone of the secondar？, system. The functionality is complemented with a substation level Station Computer, providing value added and advanced functionality. In addition required communication and time synchronization methods are presented. A life cycle cost evaluation is also performed on the proposed solution, and it is compared with the current dominant concept based exclusively on bay level devices.

Marine Current Turbine Simulator Development Based on Hardware in the Loop Simulation Concept

This paper is a contribution to the development of real time simulators for energy conversion research with respects to the ＂hardware in the loop simulation＂ concept. The focus is on the study of marine current kinetics energy conversion from into electrical energy using a marine current turbine simulator, developed in three stages. In the first stage the marine current turbine is emulated with the help of an induction drive who reproduces at its shaft the characteristics of a real turbine. It is connected with a load break used to force the emulator to respect on its shaft the characteristics of the real turbine. In the second stage, the induction drive is connected on the shaft with a doubly feed induction generator, for the study of energy conversion. The emulator respects the working regime, developed in the previous step, of a real turbine due to the control of the drive. In the third stage the induction machine emulating the turbine is interconnected with the generator and the load break. This assembly is used for the dynamic study of the marine current turbine. The break is used to create extra loads on the shaft and a variable inertial moment.