bluuebunny/crossref_metadata_2025 huggingface dataset:
Design and implementation of an indoor solar emulator based low-cost autonomous data logger for PV system monitoring
Authors: Ahmed Oday A. , Sayed Hussain K , Jalal Kanaan A , Mahmood Dhari Y. , Habeeb Waleed H.
Published: December 2019

With the growing interest in renewable energy resources, a various number of studies and development for photovoltaic (PV) systems have investigated to satisfy global needs in energy. The larger interest in PV resources has increased request for suitable apparatus with which to test PV systems. This paper deals with the design of an indoor PV source emulator using an actual PV panel to facilitate PV system testing under real environment conditions. A low-cost Arduino Mega256 microcontroller-based data acquisition system (DAQ) approach has been developed to collect the data in term of voltage, power and current based on different levels of light intensity and temperature as well as under partial shading conditions. Hence, the proposed system is not just a solar emulator but it’s a complete solar emulator-DAQ system that can emulate the sunlight and monitor the PV parameters and then collect and store the data for further research investigation. The proposed monitoring system provides real time update of the solar panel characteristics at any time in the year without relying on the weather changes. This data acquisition system will be of superior interest for undergraduate and graduate students as it is both open-source and ﬂexible. The details design of the proposed PV solar emulator and data logger and its implementation are described.
Output energy maximization of a single axis photovoltaic solar tracking system: experimental verification
Authors: Chong Shin-Horng , Chandren N. N. , Soon C. R. Allan
Published: December 2019

Major depletion of fossil fuel and the increase of greenhouse gasses such as carbon dioxide, chloroflurocarbons (CFCs), hydroflurocarbon (HFCs), perflurocarbons (PFCs) and Sulphur hexafluoride (SF6) worldwide are the catalyst for the interest of many counties towards renewable energy. The rising cost of electricity due to higher demand and less resource also led to the renewable energy venture. One of the most famous renewable energy is solar energy. Unfortunately, renewable energies are dependent on environment conditions, too. One of the major problems that affect the output energy of the solar panel is the cloud shadowing problem. Photovoltaic solar and wind hybrid system is capable to reduce the effects of the cloud shadowing by harvesting two different energy resources. However, the availability of wind energy harvesting has shown its instability performance. In this work, the photovoltaic solar array of the laboratory-scale single axis solar tracking system to maximize the output energy of the solar panel is examined experimentally. The solar array is connected in series and parallel configurations, and is experimented under different partical-shadowed conditions. The experimentation is done to develop a solar array that has a minimum effect towards this type of occurances. Experimental results proved that the parallel configured solar panel has showed less influence by the cloud shadowing as compared to the single one.
Fractional-order PID controller for permanent magnet DC motor based on PSO algorithm
Authors: Hasan Fadhil A. , Rashad Lina J.
Published: December 2019

This paper proposes the fractional-order proportional integral derivative (FOPID) controller, as a speed controller for permanent magnet direct current (PMDC) motor, instead of the traditional integer-order PID controller. The FOPID controller is the general form of the integer-order PID controllers, which found wide applications in all engineering fields. In this work a hybrid M-file and SIMULINK program is developed to simulate the overall system, the FOPID controller has five associated parameters. The optimum values of those parameters are found out by using particle swarm optimization technique. Simulation results show excellent command speeds tracking and superior dynamic response in conjunction with that of the integer-order PID controller. The proposed controller shows a high ability to overcome any external disturbance the system may be exposed; also, it performs a high degree of robustness to control the system in motoring and regenerative operating modes.
Sensorless control of PMSM with fuzzy model reference adaptive system
Authors: M’hamed Larbi , Roufaida Adjir , Nawal Ait ameur mezyane
Published: December 2019

To improve the performance of permanent-magnet synchronous motor (PMSM) drives powered by the voltage inverter with PWM control, a sensorless control scheme based on a Model Reference Adaptive System (MRAS) a fuzzy logic controller (FLC) based in with fuzzy supervisor structure. The major drawbacks of the conventional MRAS, namely chattering phenomena, high-order harmonics andexternal noise, are discussed. These drawbacks affect the estimated speed accuracy of the MRAS and reduce the control reliability of the system. To eliminate these drawbacks, an FLC is designed and integrated into the MRAS to adjust the observer gain to reduce the chattering in closed loop speed and closed loop current/torque. Comparative simulations using the proposed Fuzzy-MRAS and the conventional MRAS are performed to validate the effectiveness of the proposed FLC structure. Performance simulations of the overall proposed Fuzzy-MRAS based sensorless control scheme are performed to verify the robustness and control reliability of the system. The results show that the proposed Fuzzy MRAS has satisfactory performances with reduction of total harmonic distortion generated in the phase currents.
Modelling of three phase SVPWM AC-AC converter using unity power factor control
Authors: Saidah Saidah , Sutiksno Hari , Purwahyudi Bambang , Taufik Taufik
Published: December 2019

This paper introduces the modelling of a novel three phase AC-AC converter with indirect use of a capacitor as DC voltage link. The proposed converter has high efficiency because it uses Space Vector PWM (SVPWM) technique at both rectificier and inverter stages to operate the pulse width modulation in IGBT switches. The novel converter is equipped with a power factor control to shape the rectifier input current waveform to be sinusoidal and to be in phase with the input voltage. To keep the DC voltage stable, the converter utilizes PI controllers. Simulations are conducted for output voltage from 120 to 300 Volts with output frequency ranging from 30 Hz to 60 Hz. The simulation results show that the converter is able to maintain stable the DC voltage and current. Furthermore, the model demonstrates the benefits of proposed converter in terms of acquiring high input power factor and sinusoidal current waveform at the output side of the inverter.
MATLAB/Simulink based simulations of KY converter for PV panels powered LED lighting system
Authors: Kannan Nithiyananthan , Kannan Nithiyananthan , Thomas Sunil
Published: December 2019

The main objective of this research work is to develop KY conveter topology for renewable energy sources.Solar energy is the readily available and is the cheapest form of energy. It is non-polluting and environment friendly. The development of high static gain DC-DC converters is an important research area due to the crescent demand of this technology for several applications supplied by low DC output voltage power sources. It is used to provide the uninterruptable power supply and battery powered to the system. So here, step-up DC-DC converters based on the KY converter are proposed for LED lighting systems. The proposed topologies present high voltages and high efficiency for low input voltage and high output voltage applications. The simulation results of the proposed topology have been presented using MATLAB/SIMULINK software.
A fuzzy logic controller based brushless DC motor using PFC cuk converter
Authors: Kumar Sanatan , Roy Debanjan , Singh Madhu
Published: December 2019

This paper presents a PFC (Power Factor Correction) Cuk converter fed BLDC (Brushless DC) motor drive and the speed of BLDC motor is controlled using fuzzy logic implementation. The PFC converters are employed to enhance the power quality. The Brushless DC motor speed is under the control of DC-bus voltage of VSI-Voltage Source Inverter in which switching of low frequency is used. This helps in the electronic commutation of BLDC motors thus decreasing the switching losses in VSI. A DBR (Diode Bridge Rectifier) next to the PFC Cuk converter controls the voltage at DC link maintaining unity power factor. The characteristics of Cuk converter in four dissimilar modes of operation are studied such as continuous and discontinuous conduction modes (CCM and DCM) respectively. The entire system is simulated using Matlab/Simulink software and the simulation results are reported to verify the performance investigation of the proposed system.
Wireless power transfer through metal using inductive link
Authors: Vu Tuan Anh , Pham Chi Van , Pham Anh-Vu , Gardner Christopher S.
Published: December 2019

<span style="color: #000000; font-family: Verdana, Arial, Helvetica, sans-serif; font-size: 10px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: #ffffff; text-decoration-style: initial; text-decoration-color: initial; display: inline !important; float: none;">This paper presents a highly efficient power transfer system based on a co-design of a class-E power amplifier (PA) and a pair of inductively coupled Helical coils for through-metal-wall power transfer. Power is transferred wirelessly through a 3.1-mm thick aluminum barrier without any physical penetration and contact. Measurement results show that the class-E PA achieves a peak power gain of 25.2 dB and a maximum collector efficiency of 57.3%, all at 200 Hz. The proposed system obtains a maximum power transfer efficiency of 9% and it can deliver 5 W power to the receiver side through the aluminum barrier.
Effects of power electronics devices on the energy quality of an administrative building
Authors: Silva Jorge I. , Sousa Vladimir , Sarmiento Paulo , Gómez Julio R. , Viego Percy R. , Quispe Enrique C.
Published: December 2019

This paper proposes the analysis of the effects of power electronics devices on the energy quality of an administrative building. For the study a method is applied that allows the analysis of the main problems of energy quality such as voltage variation, harmonics, flicker, and the effect of harmonics on the power factor. As a case study, the offices of an administrative building were used, where the measurements of the main energy quality parameters were carried out for a week. The results showed the presence of current harmonics and flicker problems due to non-linear loads such as the frequency inverters that drive the motors of the elevators and escalators, as well as the LED lamps. These problems cause systematic damage to the lighting system, UPS and improper correction of the power factor. The study also demonstrates the need to deepen the effects of energy quality not only in the industrial and residential sectors. In addition, attention must be paid to the tertiary sector, specifically to administrative buildings.
Modeling of 185W of mono-crystalline solar panel using MATLAB/Simulink
Authors: Jumaat Siti Amely , Liang Ong Wei , Abdullah Mohd Noor , Radzi Nur Hanis , Hamdan Rohaiza , Salimin Suriana
Published: December 2019

This paper presents a modeling of 185W Mono-crystalline Solar Panel Using Matlab/Simulink approach. The objective of this project to carried out the efficiency and performance of Solar Panel. The type of solar panel in this project is a mono-crystalline by the SC Origin Company. A temperature and irradiance are the input parameters of the system. The outputs of the system are voltage, current and power. In addition, the data of temperature and irradiance from August to December 2017 by RETScreen Website. This data are used as an inout for PV System and the curve of I-V and P-V as the output. The data are collected at location 1.86° N, 103.09° E which is in Bandar Penggaram, Johor. The output result of I-V and P-V will be used to compare with the reference.
Design and implementation of an automatically aligned solar tracking system
Authors: Abu Sneineh Anees , Salah Wael A.
Published: December 2019

This paper presents the design and implementation of a closed-loop solar tracker system. The demand for clean energy sources has increased along with the rising demand for electrical energy and the increasing amount of environment pollution triggered by fuel consumption. Among these sources, solar energy is considered the most feasible given its wide availability and easy operation in different environments. The main purpose of this study is to maximize the generated photovoltaic power and reduce CO2 emissions by designing an efficient and low-cost solar tracking system. An aligned closed-loop solar tracker is designed and constructed to achieve the best accuracy. The proposed system shows more freedom in its movement to overcome the problems associated with the tilt of the frame-holder. A PIC microcontroller based on the Flowcode programming language is used, the position feedback is detected by using a photo-sensor, and the H-Bridge driver is used to control two DC motors. According to the experimental results, the proposed system shows significant improvements in efficiency compared with stationary solar tracking systems.
Tracking technique for the sudden change of PV inverter load
Authors: Saeed Amer Tayes , Taha Mohammed Qasim , Ahmed Abdullah Khalid
Published: December 2019

Many power electronics applications require a power calculation in the control system. To get a suitable output, engineers need to control the process and regulate the power exchange with the grid. Since real and reactive power calculations are so crucial a topic, a novel control strategy for a single-phase photovoltaic (PV) inverter has been developed. Therefore, Direct power control (DPC) and a single-phase three-level space vector pulse width modulation (SVPWM) combine as a control and modulation system. In this paper, predictive real and reactive power control and SVPWM method are conferred in the inner loop. A voltage controller based on a proportionalintegral (PI) scheme is used in the outer loop to acquire constant output voltage and provide power refers to the DPC. The performance of the proposed method is verified by using MATLAB/SIMULINK.
CLL/S Detuned compensation network for electric vehicles wireless charging application
Authors: Aziz Ahmad Fuad Abdul , Romlie Mohd Fakhizan , Zulkifli Tun Zainal Azni
Published: December 2019

An electric vehicle (EV) can be charged wirelessly through an inductively coupled power transfer system where the system resonates the inductive coupling coil at the operating frequency by means of a compensation network.  However, the resonant behaviour implies overcurrent in the inverter MOSFETs during uncoupled and high load resistor conditions, which affect to the inverter MOSFETs failure whenever the current exceeds their maximum current rating. Therefore, this paper presents a CLL/S detuned compensation network for EV wireless charging application to limit the inverter current during the uncoupled state and open circuit load conditions. The proposed compensation consists of a series capacitor and parallel inductor at the primary side and series capacitor at the secondary side.  By using Kirchhoff Voltage Law (KVL) analysis, the primary side is detuned to inductive behaviour to ensure zero voltage switching (ZVS), and the secondary side remains at natural resonant tuning. From the simulation analysis, the slight increase of the parallel inductor value at the primary side can limit of the inverter current at uncoupled and high load resistor conditions. The proposed system also offers higher efficiency than the series-series detuned compensation and slightly lower than the double-sided LCC compensation network at different coupling factor.
Solar energy density estimation using ANFIS based on daily maximum and minimum temperature
Authors: Irwanto M. , Alam H. , Masri M. , Ismail B. , Leow W. Z. , Irwan Y. M.
Published: December 2019

The data of solar energy density in one area is very important when the area will constructed photovoltaic (PV) system. The data is as preliminary study to decide what the area is suitable or not to be constructed the PV application system. But, sometime the available data is missing because the limitation of weather equipment.  An alternative technique for the available data of solar energy density should be done for the continuity of PV application system decision. An estimation technique of solar energy density is one part of good alternative to solve this problem. This paper presents the estimation of solar energy density using Adaptive Neuron Fuzzy Inference System (ANFIS). The ANFIS system has two input data of the measured daily minimum, maximum temperature and difference between maximum and minimum temperature. The measured solar energy density is as target data of ANFIS system. The data is recorded from Medan meteorological station through the web site of world weather online for the year of 2018. The result shows that the average estimated solar energy density is classified in the very high solar energy density and based on the percentage error shows that the estimated solar energy density is acceptable.
Mitigation of power quality problems using series active filter in a microgrid system
Authors: Farooqi Awais , Othman Muhammad Murtadha , Abidin Ahmad Farid , Sulaiman Shahril Irwan , Radzi Mohd Amran Mohd
Published: December 2019

Dynamic voltage restorer (DVR) is a series active filter device that is used to protect sensitive loads from power quality issues such as voltage sag, swell, harmonics or disturbances. This implies that the DVR is capable to mitigate power quality disturbances at load terminal. Harmonic is a major power quality problem polluting distribution network causing the end-user equipment to fail operating due to the occurrence of disturbances in voltage, current or frequency. This paper discusses on the DVR used as the proposed technique to mitigate the voltage sag and swell in a distribution network connected with energy storage system and mini-hydro turbine system.
Design of PI and Fuzzy Logic Controllers for Distribution Static Compensator
Authors: Reddy S.R. , Prasad P.V. , Srinivas G.N.
Published: December 2019

This paper presents study of distribution static compensator (D-STATCOM) for compensation of reactive power, harmonic distortion mitigation and load balancing in three phase three wire nonlinear load distribution system. The proposed control algorithm is developed based on synchronous reference frame theory using PI and FUZZY logic controller. The obtained reference current signal from control algorithm is compared in hysteresis band current controller for better switching of D-STATCOM. The performance of DSTATCOM with PI and fuzzy logic controller is also analysed and compared for DC voltage regulation and harmonic distortion mitigation .The proposed method is provided effective compensation for reactive power, harmonic distortion mitigation and load voltage balancing. The simulation results are obtained using MATLAB/SIMULINK soft ware.
Level Shifted Discontinuous PWM Algorithms to Minimize Common Mode Voltage for Cascaded Multilevel Inverter Fed Induction Motor Drive
Authors: Nayeemuddin M. , Reddy T. Bramhananda , Kumar M. Vijaya
Published: December 2019

This paper presents combinations of level shifted pulse-width modulation algorithm with conventional discontinuous pulse-width modulation methods for cascaded multilevel inverters. In the proposed DPWM a zero sequence signal is injected in sinusoidal reference signal to generate various modulators with easier implementation. The analysis four various control strategies namely Common Carrier (CC), Inverted Carrier (IC), Phase Shifted (PS) and Inverted Phase Shift (IPS) for cascaded multilevel inverter fed induction motor drive has been illustrated. To validate the proposed work experimental tests has been carried out using dSPACE controller. Experimental study proves that using proposed algorithms reduction in common-mode voltage with fewer harmonics along with reduced switching loss for a cascaded multilevel inverter fed motor drive has been achieved.
Artificial Intelligence Control Applied in Wind Energy Conversion System
Authors: Fatima Zohra Arama , Ismail Khalil Bousserhane , Slimane Laribi , Youcef Sahli , Benyounes Mazari
Published: December 2019

The objective of this paper is to study the dynamic response of the wind energy conversion system (WECS) based on the Doubly Fed Induction Generator (DFIG). The DFIG rotor is connected to the grid via a converter. The active and reactive power control is realized by the DFIG rotor variables control, using the field oriented control (FOC). The vector control of DFIG is applied by the use of tow regulators PI and the neural network regulator (NN). The generator mathematical model is implemented in Matlab/ Simulink software to simulate a DFIG of 1.5 MW in order to show the efficiency of the performances and robustness of the studied control systems. The simulation obtained results shows that the robustness and response time of the neural network regulator is better than those obtained by the PI classical regulator.
Optimization The Performance of a Synchronization Controller For a 3-Phase Photovoltaic Grid-Connected System
Authors: Ghita Bennis , Mohammed Karim , Ahmed Lagrioui
Published: December 2019

In a distributed generation system, divers renewable agents are connected to the low voltage 3 phase utility grid by an inverter which is used as power condition and must assurance the higher efficiency of the renewable agent. To achieve this level of efficiency, a unitary power factor between the utility grid voltages and the inverter currents is necessary, and a synchronization algorithm is required for the perfect synchronization between the 3-phase utility grid and the renewable agent. The aim of this paper is to present the optimization of the performance of a Synchronization controller for a 3-phase photovoltaic grid-connected system, assessing its accuracy under different conditions and studying their drawbacks and advantages. A grid connected photovoltaic system with a nominal power of 5 kW is used so as to assess the behavior of the synchronization algorithm when the 3 phase utility grid is affected by some disturbances such as voltage unbalances.
Application and Comparison Between the Conventional Methods and PSO Method for Maximum Power Point Extraction in Photovoltaic Systems Under Partial Shading Conditions
Authors: Ghita Bennis , Mohammed Karim , Ahmed Lagrioui
Published: December 2019

Several algorithms have been offered to track the Maximum Power Point when we have one maximum power point. Moreover, fuzzy control and neural was utilized to track the Maximum Power Point when we have multi-peaks power points. In this paper, we will propose an improved Maximum Power Point tracking method for the photovoltaic system utilizing a modified PSO algorithm. The main advantage of the method is the decreasing of the steady state oscillation (to practically zero) once the Maximum Power Point is located. moreover, the proposed method has the ability to track the Maximum Power Point for the extreme environmental condition that cause the presence of maximum multi-power points, for example, partial shading condition and large fluctuations of insolation. To evaluate the effectiveness of the proposed method, MATLAB simulations are carried out under very challenging circumstance, namely step changes in irradiance, step changes in load, and partial shading of the Photovoltaic array. Finally, its performance is compared with the perturbation and observation” and fuzzy logic results for the single peak, and the neural-fuzzy control results for the multi-peaks.
Finite-Control-Set Predictive Current Control Based Real and Reactive Power Control of Grid-Connected Hybrid Modular Multilevel Converter
Authors: Behera Rashmi Ranjan , Thakur Amarnath
Published: December 2019

This paper proposes the grid application of modified three-phase topology of Modular Multilevel Converter (MMC) using finite-control-set predictive control. This topology has reduced number of switch counts compared to the conventional MMC, eliminates the problem of circulating current and having higher efficiency. A single dc source is required to produce sinusoidal outputs. The number of sub-modules (SMs) in this topology is half of the SMs required in case of MMC, in addition to a single H-bride circuit per phase. The finite-control-set predictive current control scheme for the grid connected dc source through the Hybrid Modular Multilevel Converter (HMMC). This controller controls the desired real and reactive power demand of the grid instantaneously. The simulation study of a three phase grid connected system has been done in Matlab/Simulink and the results are provided for the different real and reactive power demands, to validate the concepts.
Performance Analysis of Supercapacitor Integrated PV Fed Multistage Converter with SMC Controlled VSI for Different Load Conditions
Authors: Pandey Shruti , Dwivedi Bharti , Tripathi Anurag
Published: December 2019

The proposed work comprises of an MPPT controlled Photovoltaic (PV) source, in conjunction with a supercapacitor, cascaded with a Sliding Mode Controlled (SMC) Inverter, supplying variable linear and nonlinear loads. The effects of varying solar irradiation and its intermittency have been effectively managed by the MPPT controlled boost converter and charge controlled supercapacitor respectively. The charge controller bucks and boosts the terminal voltage and realizes the power flow in a bidirectional manner. Seamless action has been obtained by the proposed model under varying irradiation and for varying load conditions. The performance of the SMC controlled Inverter, when compared with a PI controlled Inverter, has been found to be superior in terms of power quality and robustness of the supply system
Cogging Torque Reduction Technique on E-Core Hybrid Flux Switching Motor by Notching and Pole Pairing
Authors: Abd Rani Jaudah , Sulaiman Erwan , Ahmad Md Zarafi , Omar Mohd Fairoz , Vaithilingam Chockalingam Aravind
Published: December 2019

In the past, 4S-10P E-Core Hybrid Flux Switching Motor (HFSM) had been studied. However, the motor suffers high cogging torque but it has high performance in terms of high power and high torque at high speed. Therefore, this paper is proposing the cogging torque reduction techniques to minimize the cogging torque. The high cogging torque gave an undesirable effect during low operating speed of the motor. In order to tackle the issue, the cogging torque mechanism in equation is laid out as a form of reference. Then the reduction techniques employed on the designs and analyzed with Finite Element analysis (FEA) in JMAG. The results show the cogging torque of the optimized design is 44.45% of the motor torque. Besides, the techniques employed to identify which techniques gave the most cogging torque reduction and analyzed the geometrical difference using the cogging torque mechanism. Finally, the analysis is discussed based on the modified geometrics.
Design of Solar Powered Charging Backpack
Authors: Taverne Jonas , Muhammad-Sukki Firdaus , Syahir Ayub Ahmad , Sellami Nazmi , Abu-Bakar Siti Hawa , Bani Nurul Aini , Mas’ud Abdullahi Abubakar , Iyi Draco
Published: December 2019

This paper demonstrated a step by step process in designing a solar powered charging backpack that is capable of charging a mobile phone efficiently. A selection of existing products available on the market were reviewed and compared to ascertain the cost, size, and output capabilities. Next, the solar cell types and regulators were compared and their respective merits were also investigated. The charging system was then designed and tested before being integrated with the backpack. The results clearly showed that the system managed to charge the mobile phone. However, it was found that the excessive power dissipation has caused the linear regulator to generate significant heat.
Development of Test Vessel for Gas Insulation Breakdown Test
Authors: Zahari Ayuamira , Zainuddin Hidayat , Saufi Kamarudin Muhammad , Ambo Nur Farhani , Mohd Wari Jamaludin , Sutan Chairul Imran
Published: December 2019

This paper discusses a new test vessel developed to investigate the breakdown test performance of gas insulation. The test vessel is equipped with certain specialty including pressure chamber and control measures. Through help from a steering, it is provide of controlling the gap length of the electrodes without the need of removing the gas. Other control measures include humidity, temperature, and pressure readings. The humidity and temperature are read wirelessly and from the readings, the necessary atmospheric corrections can be made according to standards. The developed vessel is then tested with AC breakdown test using air with various gap lengths and various electrode configurations. There are two types of electrode configuration used in this project i.e., rod (R0.5)-plane and plane-plane.
Multi-Objective Evolutionary Programming for Static VAR Compensator (SVC) in Power System Considering Contingencies (N-m)
Authors: Hasma Abdullah Nor Rul , P Morgan Mahaletchumi A , Mustafa Mahfuzah , Samad Rosdiyana , Pebrianti Dwi
Published: December 2019

Static VAR Compensators (SVCs) is a Flexible Alternating Current Transmission System (FACTS) device that can control the power flow in transmission lines by injecting capacitive or inductive current components at the midpoint of interconnection line or in load areas. This device is capable of minimizing the overall system losses and concurrently improves the voltage stability. A line index, namely SVSI becomes indicator for the placement of SVC and the parameters of SVCs are tuned by using the multi-objective evolutionary programming technique, effectively able to control the power. The algorithm was tested on IEEE-30 Bus Reliability Test System (RTS). Comparative studies were conducted based on the performance of SVC in terms of their location and sizing for installations in power system.
Modular Approach to Implement Model Predictive Control on Three Phase Voltage Source Inverter
Authors: Abbasi Muhammad Abbas , Bin Husain Abdul Rashid , Alqaraghuli Hasan
Published: December 2019

A modular abstraction is presented to implement model predictive control (MPC) on a three phase two level voltage source inverter to control its output current. Traditional ways of coded implementation do not provide insights into the complex nature of MPC; hence a more intuitive, logical and flexible approach for hardware implementation is conceptualized in the form of signal flow graphs (SFGs) for estimation, prediction and optimization. Simulation results show good performance of the approach and easier code generation for real time implementation. RL load is assumed for the inverter and the importance of choosing load inductance and sampling time ratio is emphasized for better control performance.
Impacts of Photovoltaic Distributed Generation Location and Size on Distribution Power System Network
Authors: Saad N. Md. , Sujod M. Z. , Hui Ming Lee , Abas M. F. , Jadin M. S. , Ishak M. R. , Abdullah N. R. H.
Published: December 2019

As the rapid development of photovoltaic (PV) technology in recent years with the growth of electricity demand, integration of photovoltaic distributed generation (PVDG) to the distribution system is emerging to fulfil the demand. There are benefits and drawbacks to the distribution system due to the penetration of PVDG. This paper discussed and investigated the impacts of PVDG location and size on distribution power systems. The medium voltage distribution network is connected to the grid with the load being supplied by PVDG. Load flow and short circuit calculation are analyzed by using DigSILENT Power Factory Software. Comparisons have been made between the typical distribution system and the distribution system with the penetration of PVDG. Impacts in which PVDG location and size integrates with distribution system are investigated with the results given from the load flow and short circuit analysis. The results indicate positive impacts on the system interconnected with PVDG such as improving voltage profile, reducing power losses, releasing transmission and distribution grid capacity. It also shows that optimal locations and sizes of DGs are needed to minimize the system’s power losses. On the other hand, it shows that PVDG interconnection to the system can cause reverse power flow at improper DG size and location and increases short circuit level.
Review on Energy and Exergy Analysis of Air and Water Based Photovoltaic Thermal (PVT) Collector
Authors: Mustapha Muslizainun , Fudholi Ahmad , Hoy Yen Chan , Hafidz Ruslan Mohd , Sopian Kamaruzzaman
Published: December 2019

In photovoltaic thermal hybrid (PV/T) collectors, the electricity and thermal energy are produce simultaneously. PV/T technology has been proven in previous studies where it could give benefits for high energy demand supplementary. For example, in space heating, domestic water heating and also drying. The PVT collectors can be classified into air-based PVT, water-based PVT and dual-fluid (air+water) PVT collector. In this paper, the analysis of energy and exergy efficiency of PVT collectors are compiled and reviewed. This study has found that generally the energy and exergy efficiency are range from 40%-70% and 5%-20%, respectively.
A noção de mobilização do espaço em Henri Lefebvre
Authors: Alvarez Isabel Pinto
Published: December 2019

A descoberta da produção social do espaço permitiu um salto teórico na compreensão da sociedade contemporânea na medida em que atinge a dimensão espacial pelos processos de acumulação do capital e pela racionalidade do Estado. Uma possível leitura da obra de H. Lefebvre aponta a passagem do espaço social à produção do espaço por sua inserção, simultaneamente, nas tramas do processo de reprodução do capital e da sociedade. Assim, a ênfase recai sobre a noção de mobilização do espaço, através da qual pode se extrair os sentidos estratégico, econômico e político da produção do espaço. É pela mobilização do espaço que se revelam as condições concretas da produção de espaços financeirizados, envolvendo necessariamente a segregação.
Drug‐Eluting Stent Targeting Sp‐1‐Attenuated Restenosis by Engaging YAP‐Mediated Vascular Smooth Muscle Cell Phenotypic Modulation
Authors: Huang Chen , Zhao Jie , Zhu Yuelin
Published: December 2019

Background

Activation of the
YAP
(Yes‐associated protein) pathway has been demonstrated to be related to smooth muscle cells (
SMC
s) phenotypic modulation and vessel restenosis. The aim of this study was to illustrate the molecular mechanisms that regulate the expression of
YAP
during the process of
SMC
s phenotypic switch. Whether the molecular basis identified in the study could be a potential therapeutic target for drug‐eluting stents is further tested.

Methods and Results

In cell culture and in rat carotid arterial injury models, Sp‐1 (specificity protein 1) expression was significantly induced, and correlated with
SMC
s proliferative phenotype. Overexpression of Sp‐1 promoted
SMC
s proliferation and migration. Conversely, siSp‐1 transfection or Sp‐1 inhibitor Mithramycin A treatment attenuates
SMC
proliferation and migration. Through gain‐ and loss‐function assays, we demonstrated that
YAP
was involved in Sp‐1‐mediated
SMC
phenotypic switch. Mechanistically, activated Sp‐1 regulated
YAP
transcriptional expression through binding to its promoter. Moreover, we fabricated a Sp‐1 inhibitor Mithramycin A‐eluting stent and further tested it. In the rabbit carotid model, Mithramycin A‐eluting stent inhibited
YAP
transcription and attenuated in‐stent restenosis through regulating
YAP
‐mediated
SMC
phenotypic switch.

Conclusions

Sp‐1 controls phenotypic modulation of
SMC
by regulating transcription factor
YAP
. Drug‐eluting stent targeting Sp‐1 might represent a novel therapeutic strategy to prevent in‐stent restenosis.
U.S.–China Trade Conflict and the Changing Multilateral Trading System: Korea's Perspective
Authors: Suh Jin Kyo
Published: December 2019

One of the biggest risks to the world economy today is the U.S.–China trade tension. Korea is said to be particularly vulnerable to the trade conflict between the two economic giants because the United States and China are its two largest trading partners. Under the scenario that both the United States and China mutually impose 25 percent of tariffs on all imports, Korea's exports are projected to be reduced by USD 13.3 billion, just 2.2 percent of total exports in 2018. This apparent low impact is because a significant portion of Korea's exports to China are used for domestic consumption in China, not for re-export to third countries, including the United States. The adverse impact of the tit-for-tat tariffs between these two countries on Korea's exports may not be fully realized yet, however, because of the efforts by individual firms to avoid pre-announced tariffs. Thus, more time is needed to properly capture the influences of the U.S.–China trade tensions on the Korean economy.

On the other hand, the current World Trade Organization (WTO) reform led by developed countries such as the United States, EU, and Japan can be interpreted as another version of a bilateral trade conflict between the United States and China. In fact, it targets state-owned enterprises’ (SOEs) subsidies, which are the backbone of China's state-led economic development model. Furthermore, WTO reform is closely related to U.S. complaints that the WTO cannot effectively control the unfair trade practices of non-market economies like China. Considering the consensus-based decision-making mechanism of the WTO, it is highly unlikely that WTO members will derive a successful agreement on the current WTO reform. Again, the WTO is in danger of dichotomy; one group led by developed members and the other group composed mostly of developing members. Each group will try to make new trade norms suited to only their own taste.
Another Progressive's Dilemma: Immigration, the Radical Right & Threats to Gender Equality
Authors: Dancygier Rafaela
Published: December 2019

Immigration and the diversity it brings have led to the emergence of the “progressive's dilemma” whereby open societies that take in immigrant outsiders may find it difficult to maintain the solidarity required to sustain the welfare state. In this essay, I address another progressive's dilemma: Focusing on the case of Western Europe, I argue that when open borders give rise to radical-right parties, immigration can inadvertently also endanger progressive achievements in gender equality. Though xenophobic policies frequently constitute their core message and the primary source of their appeal, radical-right parties are also defenders of traditional family values and outspoken critics of measures that promote the economic and political advancement of women. Moreover, the composition of these parties, both in terms of voters and politicians, is disproportionately male. As a result, when radical-right, anti-immigrant parties enter national parliaments, the descriptive and substantive representation of women suffers, sometimes reversing long-held gains in gender equality.
Donald Trump's Gift to Feminism: The Resistance
Authors: Chira Susan
Published: December 2019

Donald Trump's surprise win in 2016 galvanized once-politically quiescent women and jolted those who had believed second-wave feminist victories were enduring. This “resistance” drew on two potent forces: the passion of the newly awakened, primarily grassroots participants; and the organizing experience of professionals and institutions determined to channel that passion into sustainable electoral and policy gains. The movement expanded beyond the political to encompass the social and cultural spheres and gave women of color a place in the spotlight. As women ran for national, state, and local office in record numbers, the #MeToo movement toppled men who once harassed with impunity. Record numbers of women won in the 2018 midterms, retaking the U.S. House of Representatives for the Democrats, and six women declared their candidacy for president in 2020. But it remains unclear whether these gains will be lasting and overcome remaining ambivalence about women and power.
Sexual Harassment of Women Leaders
Authors: Folke Olle , Rickne Johanna , Tanaka Seiki , Tateishi Yasuka
Published: December 2019

Sexual harassment is more prevalent for women supervisors than for women employees. This pattern holds in the three countries we studied – the United States, Japan, and Sweden – where women supervisors are between 30 to 100 percent more likely to have been sexually harassed in the last twelve months. Among supervisors, the risk is larger in lower- and mid-level positions of leadership and when subordinates are mostly male. We also find that harassment of women supervisors happens despite their greater likelihood of taking action against the abuser, and that supervisors face more professional and social retaliation after their harassment experience. We conclude that sexual harassment is a workplace hazard that raises the costs for women to pursue leadership ambitions and, in turn, reinforces gender gaps in income, status, and voice.
Cooperation & Conflict in the Patriarchal Labyrinth
Authors: Folbre Nancy
Published: December 2019

This essay offers a new way of visualizing structures of collective power based on gender, emphasizing the role of social institutions in shaping women's ability to bargain over the distribution of the gains from cooperation with men. It makes the case for an interdisciplinary conceptualization of bargaining power that emphasizes the role of imperfect information and inefficient outcomes, and explains important parallels between structures of collective power based on gender, age, and sexuality, and those based on other dimensions of socially assigned group membership such as race, ethnicity, citizenship, and class. Recognition of the importance of reproductive work helps advance the project of developing intersectional political economy.
Analytical Multisensory Trainable System for Diagnosing Vocational Aptitude of Military Medical Specialists by Ion Content in the Expired Breath Condensate
Authors: Kislyakov Yury Ya. , Avdyushenko Sergey A. , Kislyakova Larisa P. , Zaitceva Anna Yu.
Published: December 2019

A new principle of non-invasive diagnostics and biomedical research has been implemented using artificial analytical multisensory trainable system for assessing and monitoring the human functional state by non-invasive methods based on integral electrochemical and optical parameters
of liquid and gaseous media of the body (exhaled air, condensate, etc.). The results of biomedical tests in a military personnel group show that the subjects are divided into groups of different adaptability and sensitivity to extreme conditions. The proposed method based on the multisensory
trainable diagnostic system allows for the selection and non-invasive instrumental control over the vocational aptitude of specialists of hazardous occupations for their functioning in extreme conditions.
Mathematical Models of the Ocurved Spring Tubes Surfaces
Authors: Vorontsova Valeriya Leonidovna , Bagoutdinova Alfiya Gizzetdinovna , Gilemzianov Almaz Fernandovich
Published: December 2019

One of the ways to intensify heat exchange processes is the creation of compact heat exchangers with a developed heat exchange surface. It is known that coil-type channels provide a developed heat exchange surface and belong to one of the most efficient and technological designs of
heat exchange elements. In this regard, the authors proposed a small-size heat exchanger of the “pipe in pipe” type with an internal coil spring-twisted channel, and the authors of the proposed article developed mathematical models describing the heat-exchange surfaces of pipes
of complex configurations, including coil spring-coiled channels. The equations of heat transfer surfaces are written in vector-parametric form based on the fundamental principles of analytical and differential geometry. In order to verify the adequacy and visualization of the written equations,
surfaces were constructed using the Matlab application software package. The proposed mathematical models can be used in computer simulation of hydrodynamic processes during the flow of liquid media in curved channels, which will allow to explore and further optimize their internal geometry
by changing the parameters of the equations. This work is a continuation of research on the creation of efficient heat exchangers.
Convolution Neural Networks for Binary Classification
Authors: Srinivas K. , Kavitha Rani B. , Varaprasad Rao M. , Madhukar G. , Venkata Ramana B.
Published: December 2019

Convolutional neural networks (CNNs) are similar to “ordinary” neural networks in the sense that they are made up of hidden layers consisting of neurons with “learnable” parameters. These neurons receive inputs, perform a dot product, and then follows it with
a non-linearity. The whole network expresses the mapping between raw image pixels and their class scores. Conventionally, the Softmax function is the classifier used at the last layer of this network. However, there have been studies conducted to challenge this norm. Empirical data has shown
that the CNN model was able to achieve a test accuracy of ≈99.04% using the MNIST dataset. MNIST dataset consists of 60,000 training images and 10,000 testing images. This experiment was inspired by following the experiment on MNIST dataset. The dataset we used in this experiment is
collection of images consisting of cats and dogs. These images are gathered from different sources over internet. This dataset consists of 10,000 images of each class i.e., Cats and Dogs. The overall accuracy of training and validation set is 96.85%. The said results may be improved if data
pre-processing techniques were employed on the datasets, and if the base CNN model was alternatively more sophisticated than the one used in this study.
Rare Atmospheric River Caused Record Floods across the Middle East
Authors: Dezfuli Amin
Published: December 2019

Atmospheric rivers (ARs) are responsible for some of the hydroclimatic extremes around the world. Their mechanisms and contribution to flooding in the Middle East are relatively poorly understood. This study shows that the record floods during March 2019 across the Middle East were caused by a powerful AR, originated from the North Atlantic Ocean. Iran, in particular, was substantially affected by the floods. The nearly 9,000-km-long AR propagated across North Africa and the Middle East, and was fed by additional moisture from several other sources on its pathway. Simultaneous presence of a midlatitude system and a subtropical jet facilitated the moisture supply. The AR, as passing over the Zagros Mountains, produced record rainfall induced by the orographic forcing. The resulting floods caused widespread damage to infrastructures and left a death toll of at least 76 in Iran.