bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of PV array configuration under different partial shading condition
Authors: Ishak Mohammad Syahir Bin , Salimin Rahmatul Hidayah , Musirin Ismail , Hamid Zulkiffli Abdul
Published: December 2019

This paper investigates the performances of different photovoltaic (PV) array under several shading condition. Four types of photovoltaic array configuration scheme which are ‘Series’ (S), Series-Parallel’ (SP), Total-Cross-Tied’ (TCT), and ‘Bridge-Link’ (BL) array topologies were tested by applying a 6x6 PV array under 6 different shading scenarios. The modeling is developed using Matlab/Simulink. The performances and output characteristics of photovoltaic array are compared and analyzed. System engineer can use the detailed characteristics of different array configuration to approximate the outcome power and pick the best configuration of the system by concerning the current natural condition to enhance the overall efficiency.
Energy efficiency enhancement using dynamic voltage restorer (DVR)
Authors: Othman Muhammad Murtadha , Rakami Nik Muhamad Lokman Fahmi Nek , Hamid Zulkiffli Abdul , Musirin Ismail , Othman Mohammad Lutfi
Published: December 2019

Dynamic voltage restorer (DVR) is a device that can compensate harmonic, voltage sag and voltage swell condition that exists in a three-phase system. Other than that, DVR can also be used to enhance the energy efficiency or energy saving by reducing excessive amount of incoming power via the reduction incoming voltage at allowable limit. The DVR can inject the required voltage in the system so that the interruption of supply voltage can be compensated. The compensation of voltage supply interruption is improved based on the hysteresis voltage output of controller used in the DVR to detect the difference between reference voltage and disrupted voltage. The hysteresis voltage control mainly controlled by relays switching so that the signal can be sent to IGBT switches controller. The hysteresis voltage control and unipolar SPWM is supplied to control the IGBT switches by the DC supply for voltage interruption compensation. The unipolar SPWM technique converts the DC supply voltage into AC supplied voltage, thus making the DVR injection become easier to inject the AC voltage into the system to compensate voltage sag and voltage swell.
Investigation of distributed generation units placement and sizing based on voltage stability condition indicator (VSCI)
Authors: Raj Arvind , Aziz Nur Fadilah Ab , Yasin Zuhaila Mat , Salim Nur Ashida
Published: December 2019

Voltage instability in power distribution systems can result in voltage collapse throughout the grid. Today, with the advanced of power generation technology from renewable sources, concerns of utility companies are much being focused on the stability of the grid when there is an integration of distributed generation (DG) in the system.  This paper presents a study on DG units placement and sizing in a radial distribution network by using a pre-developed index called Voltage Stability Condition Index (VSCI). In this paper, VSCI is used to determine DG placement candidates, while the value of power losses is used to identify the best DG placement. The proposed method is tested on a standard 33-bus radial distribution network and compared with existing Ettehadi and Aman methods. The effectiveness of the method is presented in terms of reduction in power system losses, maximization of system loadability and voltage quality improvement. Results show that VSCI can be utilized as the voltage stability indicator for DG placement in radial distribution power system. The integration of DG is found to improve voltage stability by increasing the system loadability and reducing the power losses of the network.
Comparisons of PI and ANN controllers for shunt HPF based on STF-PQ Algorithm under distorted grid voltage
Authors: Omran Mohamed Asghaiyer , Ibrahim Izzeldin. I. , Ahmad Abu Zaharin , Salem Mohamed , Almelian Mohamad Milood , Jusoh Awang , Sutikno Tole
Published: December 2019

This paper proposes a shunt hybrid power filter (HPF) for harmonic currents and reactive power compensation under a distorted voltage and in a polluted environment. For this purpose, the reference current of the shunt HPF is computed based on the instantaneous reactive power (p-q) theory with self-tuning filter (STF). In order to adjust the dc voltage as a reference value, PI and ANN controllers have been utilized. Moreover, the system has been implemented and simulated in a MATLAB-SIMULINK platform, and selected results are presented. Therefore, the results verified the good dynamic performance, transient stability and strong robustness of the ANN controller. Furthermore, the shunt HAPF with ANN controller has been found to be in agreement with the IEEE 519-1992 standard recommendations on harmonic levels.
A comparative study of cascade H-bridge multilevel voltage source inverter and parallel inductor multilevel current source inverter
Authors: Nik Ismail Nik Fasdi , Hashim Norazlan , Johari Dalina
Published: December 2019

This paper presents the analysis study between multilevel inverters that are often classified into multilevel voltage source and multilevel current source inverters.  For multilevel voltage source inverter (MVSI), the specific topology studied for this work is the Cascaded H-Bridge MVSI.  Whereas, the multilevel current source inverter (MCSI) is based on Paralleled Inductor Configuration MCSI.  For this study, the analysis between these converters are done with respect to the number of components, the advantages and disadvantages of each converters during performing inverter operation. In term of output voltage and current quality, the percentage of the Total Harmonic Distortion (THD) are measured and compared for both topologies.  MATLAB/Simulink software has been used in this research to design and simulate in order to study the performances of both inverters.
Optimum design of dynamic voltage restorer for voltage sag mitigation in distribution network
Authors: Chinmay Deshpande V. , Chaitanya Deshpande V.
Published: December 2019

DVR is power electronic based device used for mitigation of voltage sag problem. In this paper, various inverter topologies such as Voltage source inverter, Z source inverter and Embedded Z source inverter are used and compared for operation of DVR. Here dual p-q theory is implemented as control technique which have excellent transient response and speed. Different inverter configurations are implemented for DVR and its simulation results are presented and compared. It has been observed that Embedded EZ source inverter topology is found to be effective. The Embedded EZ source inverter topology and its hardware results are presented and compared.
Input switched closed-loop single phase ĈUK AC to DC converter with improved power quality
Authors: Arifin Md. Shamsul , Mohammad Nur , Khalil Mohammad Ibrahim , Alam Mohammad Jahangir
Published: December 2019

A new closed loop AC to DC ĈUK converter is presented in this paper. The conventional ĈUK AC to DC converter has no feedback circuit. Thereby, the output voltage of the converter changes while changing the load. The proposed closed loop converter can regulate voltage with the variation of load over a wide range. Moreover, the power factor and Total Harmonic Distortion (THD) of the supply side current found quite satisfactory from this closed loop ĈUK converter. The converter operates in four steps with a different combination of voltage polarities and switching states. The feedback path consists of a voltage control loop and a current control loop. The closed loop ĈUK converter in this study is compared with the open loop version. Additionally, the comparison is made with the conventional converter of the same topology. The effectiveness in terms of power factor and THD of the proposed converter is verified using simulation results.
Improved design of a DC-DC converter in residential solar photovoltaic system
Authors: Darameičikas Mantas , Sukki Firdaus Muhammad , Bakar Siti Hawa Abu , Sellami Nazmi , Bani Nurul Aini , Muhtazaruddin Mohd Nabil , Mas’ud Abdullahi Abubakar , Rey Jorge Alfredo Ardila
Published: December 2019

With growing demand in renewable energy, solar photovoltaic (PV) technology is becoming more popular. A number of research has been carried out to increase the efficiency of the PV system. One of them is improving the Switch Mode Power Supplies (SMPS) performance to ensure maximum solar energy extraction. This paper looks at buck type SMPS suitability for use in solar PV installed in residential houses. The main issues that affect the response from the output are identified. The work will utilise the LT SPICE software to carry out the simulation. The primary objective of the study is to design an improved converter controller which is more robust and is able to maintain constant output. The emphasis is on good efficiency, stability and low output voltage ripple. This could be achieved by using the current mode control (CMC) techniques – an alternative design to the voltage mode control technique (VMC). Results obtained via simulations reveal strong evidence of CMC superiority over the VMC.
Review of AC-DC power electronic converter topologies for power factor correction
Authors: Sasikala Rajagopal , Seyezhai R.
Published: December 2019

Increased harmonic content and low power factor in power systems caused by power converters have been of great concern. To overcome this, several converter topologies employing advanced semiconductor devices and control schemes have been proposed. The aim of this paper is to identify a low cost, small size, efficient and reliable ac to dc converter to meet the input performance index of uninterrupted power supply. In this paper, comparison between three converters namely AC-DC Cuk rectifier, Fly back converter & Interleaved SEPIC converter have been carried out. For the above converters both bridged and bridgeless topologies have been analysed. The working of all the three types of converter has been   illustrated with relevant waveforms followed by the simulation results. Comparison of the three converters have been done based on the parameters namely Displacement Factor, Supply Power Factor& supply THD. The results are verified.
Potential of floating solar technology in Malaysia
Authors: Jamalludin Mohd Alif Saifuddin , Sukki Firdaus Muhammad , Bakar Siti Hawa Abu , Ramlee Fadzliana , Munir Abu Bakar , Bani Nurul Aini , Muhtazaruddin Mohd Nabil , Mas’ud Abdullahi Abubakar , Rey Jorge Alfredo Ardila , Ayub Ahmad Syahrir , Sellami Nazmi
Published: December 2019

Solar energy is a natural source of energy and is tremendously abundant. The concept of floating solar is to fulfil and to support the existing energy supply in order to enhance the human life. The floating solar exploits the massive availability of ocean region and the severe unavailability of land. The main purpose of this paper is to evaluate the potential of floating solar to be deployed in coastal or infield in Malaysia. It was predicted that such system could generate around 14,530 MWh per annum in Malaysia. It can be concluded that floating solar could be one of the most important ocean structures in the future because it is reliable, flexible and has virtually low cost production comparing with other ocean structures
Power compensation for vector-based current control of a modular multilevel converter (MMC) based STATCOM
Authors: Lawan Abdurrahman Umar , Babani S. , Abdulkarim A. , Shehu G. S. , Jibril M Y. , Madugu I. S.
Published: December 2019

This paper studies the suitability of a vector based current control which is mostly employed for its faster response in the reactive current applications of static compnesators (STATCOMs). The current control is mostly achieved using proportional-integral (PI) controllers because of  the advantage of their good tracking and small variations. However, due to the dependency of PI controllers on the modular multilevel converter (MMC) system dynamics, performance variations arise during steady-state STATCOM non-ideal operations. This paper presents an improved MMC based STATCOM control with a d-q compensation algorithm added to the vector based current control. The algorithm is derived to tackle the effects of the dynamics of the MMC and the STATCOM ideal variations without the use of any additional controller. The control is achieved by providing a power compensation in the d,q-axis which injects currents at the input of the PI controllers in order to improve the steady-state performance of the STATCOM control.
Modular multilevel converter (MMC) based STATCOM with vector control and virtual impedance voltage compensations
Authors: Lawan Abdurrahman Umar , Almurib Haider A.F. , Khor Jeen G.
Published: December 2019

This paper presents modular multilevel converter (MMC) with circulating current control which provides an improved balanced capacitors voltages. The control is achieved by employing compensation techniques in the external and internal controls of the MMC based static compensator (STATCOM). Performance variations arise during STATCOM non-ideal operation with grid externally and during capacitors voltage transients due to charging and discharging within the MMC that result in the emergence of a voltage disturbance. The proportional integral (PI) controller is usually employed in the external and internal controls for a fast response and reactive current control. In this paper, the performance of the PI controller is improved using voltage compensation in the external control and virtual impedance in the capacitor voltage control within a five-level MMC. The proposed control minimizes the variations in the STATCOM operations with the grid and within the MMC to provide an enhanced overall system response.
A model for predicting photovoltaic module performances
Authors: Bouaziz Nadia , Benfdila Arezki , Lakhlef Ahcene
Published: December 2019

The present paper deals with the development of a simulation model for predicting the performances of a solar photovoltaic (PV) system operating under current meteorological conditions at the site location. The proposed model is based on the cell equivalent circuit including a photocurrent source, a diode, a series and shunt resistances. Mathematical expressions developed for modeling the PV generator performances are based on current-voltage characteristic of the considered modules. The developed model allows the prediction of PV cell (module) behavior under different physical and environmental parameters. The model can be extended to extract physical parameters for a given solar PV module as a function of temperature and solar irradiation. A typical 260 W solar panel developed by LG Company was used for model evaluation using Newton-Raphson approach under MATLAB environment in order to analyze its behavior under actual operating conditions. Comparison of our results with data taken from the manufacturer’s datasheet shows good agreement and confirms the validity of our model. Hence, the proposed approach can be an alternative to extract different parameters of any PV module to study and predict its performances.
Ultra fast frequency independent instantaneous power factor detector
Authors: Omran Safaa S. , Al-Khalid Ali. Sh. , Yaseen Amer Atta
Published: December 2019

Many schemes were attempted to lessenthe time taken for measuring the
power factor of a linear load. This paper suggests taking advantage of a
previous paper where only two samples of the voltage and current were
adequate to have a very fast calculation method of the power factor. That
scheme used a phase locked loop (PLL) as a frequency multiplier scheme to
acquire two progressive samples of the voltage and current which are
concurrent. The time elapsed for measurement was the reciprocal of the PLL
sampling frequency; no further scheme was reported after that to claim a
faster method. This paper gets use of that work to get two progressive
samples of voltage and current separated by a short time. The scheme is
frequency independent with an indication for lead lag. All the operations are
executed by a PIC microcontroller rather than a computer with few support
circuits. The output will be shown either in digital or analogue (DC) form.
The percentage of error depends mainly on the resolution (number of bits)
for both the ADC and DAC used.
Comparative analysis of cascaded fuzzy-PI controllers based-MPPT and perturb and observe MPPT in a grid-connected PV system operating under different weather and loading conditions
Authors: Otmane Harici , Mouloudi Youssef , Mokhtar Bendjebbar
Published: December 2019

In this paper, a comparison is carried out between MPPT technique using a hybrid cascaded Fuzzy-PI Controller and Perturb and Observe (P&O) MPPT technique. The two techniques are compared in a system which consists of a photovoltaic system connected to a grid via a two-level three-phase inverter. The P&O and Fuzzy-PI techniques are examined under different weather conditions, namely, ramp change in irradiation level and ramp change in temperature levels. Disturbances represented by fluctuations in power demand from the utility grid is generated to assess the robustness of each of the two controllers. The Fuzzy-PI based MPPT, has  proved its excellent tracking and robustness against abrupt perturbations. Simulations of the system performances using the two regulators are performed to validate the conceptual standings.
Analysis of solar energy technology in leading countries
Authors: Kaliappan Kannan , Sankar M , Karthikeyan B , Vineeth Budamkayala , Raju V. Chetan
Published: December 2019

In the present generation energy plays a vital role in our world and for human life it´s very important factor. There is a methodical meeting taking place regarding the conservation of energy and every time there is a review in the agenda. Energy demand and supply were endeavored by these countries. To rectify these problems, there should be more research in the generation of energy with the greater efficiency and try to use energy in more efficient manner. Solar energy remains as the most prominent source of energy as it is cost effective and environmentally friendly. Reviews convey that solar energy systems will play a major role in the power generations. As per present scenario there is a great importance to the solar energy using photovoltaic systems. Photovoltaic systems exhibit an important role for solar energy production.
Grid tied PV System using modular multilevel inverter
Authors: N. Sujitha , Subudhi Partha Sarathi , S. Krithiga , S. Angalaeswari , T. Deepa , D. Subbulekshmi
Published: December 2019

A grid tied photovoltaic system using modular multilevel inverter topology is proposed in this paper. Basic unit structure of modular multilevel inverter used in this system is capable of converting DC power from PV array to AC power for feeding power to the household loads or utility grid. The proposed modular multilevel inverter structure has lesser power electronic devices compared to the existing multilevel inverter topologies. The proposed system generates a nearly sinusoidal signal and achieves better output profile with low total harmonic distortion. Simulation of the proposed system is carried out in MATLAB/Simulink software and the results are presented.
Efficiency and energy modelling for PVT air collector with extended heat transfer area: a review
Authors: Fudholi Ahmad , Fazleena Musthafa Mariyam , Taslim Ivan , Ayu Indrianti Merita , Noviantari Manyoe Intan , Yusof Othman Mohd
Published: December 2019

Solar energy is renewable and environment friendly and has been widely used in electricity generation and thermal energy through photovoltaic thermal (PVT) system. This system is beneficial in terms of maximum energy generation and cost of usage. The growing concern on energy sources and their usage has increased the significance and demand for PVT collectors. A PVT air collector consists of a PV panel and a thermal collector system. In PVT air collector, electricity and thermal energy are generated simultaneously. This review focuses on efficiency and energy modelling for PVT air collector with extended heat transfer area. Findings of this review indicated that PVT air collector with extended heat transfer area produced PVT efficiency higher than conventional PVT air collector. The thermal efficiency of PVT air collector for with and without extended heat transfer area are 21-83% and 12-70%, respectively, which the improvement of thermal efficiency is 15.7-42.8%.
Smooth transition from grid to standalone solar diesel mode hybrid generation system with a battery
Authors: Elsherbiny Aya M , Nada Adel S. , Ahmed Mohammed Kamal
Published: December 2019

This paper described a self-supply smart microgrid which may be a low voltage or medium voltage  distribution network. It considered an efficient energy system in which different renewable sources as photo-voltaic array, wind, or conventional as diesel generator, and storage called distributed generators  which organized to chance the load power demand at any time with reliability. It can operate either  on-grid or off-grid configuration, especially limited areas far from the utility grid needed another backup power. By using Matlab/Simulink, a solar PV system is modeled, simulated, and determined the characteristic of a particular photovoltaic cell panel under the influence of different values of ambient conditions. Taking into consideration MPPT algorithm which increases the solar energy efficiency by Incremental conductance technique to track MPP correctly with fast response. Power electronic DC/DC converter and DC/AC inverter are used with PWM technique. To compensate the power fluctuations of the system under different possible transient cases, a high performance control based on an improved virtual synchronous generator is added to confirm smooth variants in voltage, frequency and active power during transient conditions. The results show the PV/Diesel generator/battery/power/frequency and voltage performance at two different conditions.
PV array connected to the grid with the implementation of MPPT algorithms (INC, P&O and FL Method)
Authors: Lagdani Oumnia , Trihi Mourad , Bossoufi Badre
Published: December 2019

The purpose of this article is to extract the maximum power point at which the photovoltaic system can operate optimally. The system considered is simulated under different irradiations (between 200 W/m2 and 1000 W/m2), it mainly includes the established models of solar PV and MPPT module, a DC/DC boost converter and a DC/AC converter. The most common MPPT techniques that will be studied are: "Perturbation and Observation" (P&O) method, "Incremental Conductance" (INC) method, and "Fuzzy Logic" (FL) control. Simulation results obtained using MATLAB/Simulink are analyzed and compared to evaluate the performance of each of the three techniques.
Study of automatic generation control in two area power system with DFIG-based wind energy conversion
Authors: Kail Soumia , Bekri Abdelkader , Hazzab Abdeldjebar
Published: December 2019

The main objective of Automatic Generation Control (AGC) is to keep the frequency within specified limits through primary and secondary control. In this study, a model of two area thermal non-reheat power system with integration of Doubly Fed Induction Generator (DFIG) based Wind Energy Conversion (WEC) into both areas is presented. A Proportional Integral Derivative (PID) controller and a Fuzzy Logic Controller (FLC) have been applied and compared. The Proposed controllers are used to improve the dynamic response as well as to reduce or eliminate the steady-state error in Area Control Error (ACE). FLC has been offered better and faster performance over the PID controller. The results obtained prove the impact of DFIG-based WEC on AGC and confirm the participation of the DFIG in the frequency system.
Design and implementation a security system for bank using voice recognition
Authors: Ali Mohammed Hasan , Al Azze Qasim Mohamed
Published: December 2019

In this work, a new security system design is demonstrated based on the sound signal for bank protection. Voice Acknowledgment Module is placed on the gate of the safe. Voice Acknowledgment Module is set to perceive the capable client as indicated by his sound recurrence reaction. The plan could program to permit tow clients for greater adaptability the card location strategy is executed utilizing individual data information to permit other client in the framework. A delicate camera is accustomed to observing the developments in the structure and for the reasons for wellbeing and security. All these sensors are controlled by arduino. 
Experimental investigation of artificial intelligence applied in MPPT techniques
Authors: Krachai Saidia Della , Stambouli A. Boudghene , Krachai M. Della , Bekhti M.
Published: December 2019

Nano-satellites are key features for sharing the space data and scientific researches. They embed subsystems that are fed from solar panels and batteries. Power generated from these panels is subject to environmental conditions, most important of them are irradiance and temperature. Optimizing the usage of this power versus environmental variations is a primary task. Synchronous DC-DC buck converter is used to control the power transferred from PV panels to the subsystems while maintaining operation at maximal power.  
In this paper, artificial intelligence techniques: neural networks and adaptive neural fuzzy inference systems (ANFIS) are used to accomplish the tracking task. Simulation and experimental results demonstrate their efficiency, robustness and tracking quality.
Universal power converter for low power applications
Authors: Asna M. , Shareef H. , Khalid S. N. , Idris A. O. , Aldarmaki A. N. , Hamed Basil
Published: December 2019

A novel power converter that can perform both voltage and frequency conversion was proposed. Inappropriate power supply can damage sensitive sub-components and render the connected device inoperable. Henceforth, the proposed voltage–frequency converter acts as an interface to plug any electrical device directly into an electrical socket and provide the voltage and frequency required. The converter used a synchronous reference frame proportional–integral (SRFPI) controller to regulate the instantaneous output voltage and to improve steady state performance. Because the PI controller works together with the synchronous reference frame controller, it is difficult to tune the PI control parameters. To overcome this issue, a new meta heuristic optimization technique called lightening search algorithm (LSA) optimization was used to identify the optimum PI parameter values. A detailed description of the system operation and control strategy was presented. Finally, the performance of the converter was analyzed and verified by simulation and experimental results. The experimental result has shown that the proposed system has satisfactory output voltage and frequency under different input voltages.
Genetic algorithm to improve power output of photovoltaic system under partial shaded condition
Authors: Ibrahim Abdalla Eltigani , Nor Nursyarizal Mohd , Nawi Illani Binti Mohd , Fakhizan R Mohd , Mohd Khairul Nisak
Published: December 2019

The Partial Shaded Condition (PSC) is a process of non-optimal power capture in photovoltaic (PV) system; it will happen when one or all the PV solar cells get shaded by external factors. This phenomenon makes a sudden change in cell irradiance and lead to non-optimal power capture and reduces the generated power in PV systems. Cell under PSC generates one global peak (GP) and many local peaks (LPs), but the tracking of GP under (PSCs) effectively are still a big challenge to the researchers. In this paper, Fuzzy Logic Control (FLC) and optimized FLC algorithms were developed to track the PV power during the PSCs. The configuration of both algorithms are designed, simulated and evaluated using MATLAB/Simulink and their performance was compared with other literature techniques to study their capability to track the MPPT under PSCs. Proposed GA-FLC achieved 0.7 S as tracking time to find and track the Global Peak of Maximum power Point (GMPP) under PSCs and the usage of buck/boost converter in this technique achieved 98.5% of tracking accuracy. GA-FLC shows good dynamic performance in terms of tracking accuracy and complexity under PSCs compared to other techniques.
Significant implication of unified power quality conditioner in power quality problems mitigation
Authors: Hasan Kamrul , Othman Muhammad Murtadha , Rahman Nor Farahaida Abdul , Hannan M. A. , Musirin Ismail
Published: December 2019

This paper presents an analysis of a three-phase unified power quality conditioner (UPQC) in terms of design and performance. A back to back connection of a series compensator and a shunt compensator with a common DC-bus is utilized to build the UPQC model. The series compensator compensates the power quality problems such as grid voltage sags/swells for the grid side. During sag and swell condition, the compensated voltage is injected by the series compensator in phase with the point of common coupling (PCC) or out of phase with PCC. The load current harmonics is compensated by using the shunt compensator. The dynamic performance and  the steady state of the designed model are analyzed by using MATLAB-Simulink under several disturbances such as PCC voltage harmonics, voltage sags/swells and load unbalancing using a nonlinear load. 
Intelligent control of DC-DC converter based on PID-neural network
Authors: Khleaf Hussain K. , Nahar Ali Kareem , Jabbar Ansam Subhi
Published: December 2019

This paper introduced a “PID-NN” based on Particle Swarm Optimization control that was applied to a boost converter operating in large-signal domains. Simulation results have shown that the proposed “PID-NN controller” could enhance the (boost converter) startup response with the use of fewer on-off switch operations compared to the Conventional “PID controllers”. This result is of high importance in practice since reducing the number of on-off switches can effectively decrease the transient disturbances and losses due to switching. Simulations also prove that the proposed “PID-NN controller” is capable of efficiently improving rejecting potential disturbances that could happen in the input voltage. Moreover, it has been noticed that the output voltage is more efficiently controlled when applying “PID-NN controller”. The results of the simulation show the efficiency of the suggested algorithm compared with other well-known learning methods.
Experimental Validation of Single Phase Series Active Power Filter Using Fuzzy Control Technique
Authors: Ben Abdelkader Abdallah Alla , Abdelkhalek Othmane , Allali Ahmed , Meftouhi Abdelmalek , Toumi Toufik
Published: December 2019

The aim of this paper is illustrating and exposing the performance of a Series Active Power Filter (SAPF) with PI controller and Fuzzy controller within simulation and experimental validations. This performance is best manifested in compensating the sags and the swells voltages and in eliminating the harmonic voltage and regulate the terminal voltage of the load by injecting a voltage component in series with source voltage which is increased or decreased from the source voltage, hence, maintaining the load side waveforms as pure sinusoidal. The control method used in this work is not so complex and it is based on a phase locked loop (PLL) that is used to control the active filter. It is valid only in the phase system. The efficiency of the method I suggested is affirmed through simulation results by MATLAB\Simulink® and some prototypes experiments. These results shows the capability of the proposed prototypes
Comparison of Different Control Techniques for Interleaved DC-DC Converter
Authors: Kavitha M. , Sivachidambaranathan V.
Published: December 2019

Interleaved DC-DC converter with coupled inductor is used in standalone Photovoltaic, battery charger/discharger application. The main issue of the Interleaved DC-DC converter is that, it does not provide constant output voltage for a change in input voltage. Therefore, the converter efficiency is reduced. Hence to overcome this drawback, proper controller has to be used. In this paper, different control techniques such as PI, PID and Fuzzy logic controller are used. The simulation results of all three controllers were done using MATLAB/Simulink and compared. Fuzzy logic controller provides better regulated output voltage with less settling time of 0.04sec.
Performance Measures of Positive Output Superlift Luo Converter Using Multitudinous Controller
Authors: Ponnalagarsamy Sivagami , Jothi Swaroopan N. M.
Published: December 2019

In order to meet the increase in energy demand globally it is necessary to harness renewable energy at its maximum potential for the purpose of electric power generation. For the achievement of high output voltage and efficiency DC-DC converters plays a vital role in low voltage PV array and fuel cells. LUO converters are gaining importance because of geometric progression output. . LUO converters find its application because of high transient performance of the system, high power transfer gain, efficiency  and  reduced ripple .Because of load and line disturbances the output voltage of DC-DC converter must be operated in closed loop mode. This paper interpolates multitudinous controller for positive output elementary super lift LUO converter (POESLL). The pursuance of the converter under manifold such as variation in input, load are developed and compared for current mode controller and   SMC.
Smart Monitoring System of DC to DC Converter for Photovoltaic Application
Authors: Kadhim Abed Jameel
Published: December 2019

This paper presents a new smart monitoring system designed based on dc to dc converter for photovoltaic application. This system design according two parts to monitor input-output voltages and currents for dc/dc converter, (a) control system: the control system using Arduino NANO as microcontroller to read the measuring voltage and current values from sensor circuits of voltage and current. The measuring data send by Bluetooth HC-05 to end user (monitor system). Bluetooth as wireless communication between the control system and monitoring system (end users). (b) monitoring system: The monitoring system application program as a new application designed to monitor the received data from control system from safety distance (around 10m). the application program designed by the open source AppyBuilder software. The AppyBuilder is an open source software for easily building Android smartphone application. The advantages of the final circuit can be used to monitor step-up or step-down topologies, low-cost, and high-efficiency performance.
Analysis and Design of Single Phase High Efficiency Transformer less PV Inverter Topology
Authors: N. S. Jayalakshmi , Kumar Ankit , Kumar Ashish
Published: December 2019

An inclination towards renewable energy resources has been increased due to the requirement of clean environment and to satisfy the increasing power demand for the long run. A grid connected system requires the availability of a transformer in its power conversion stages that provides galvanic isolation between the grid and the power system. But inclusion of transformer results in making the system bulky and more expensive. In this paper different transformer-less PV inverter topologies are analyzed by comparing their efficiency, leakage current and THD of load current using MATLAB/Simulink environment. In order to achieve maximum power, maximum power point tracking (P&O algorithm) is used. From the simulation results, modified HB-ZVR is found to have minimum leakage current and constant common mode voltage with higher efficiency. Also, the hardware results are obtained for modified HB-ZVR topology.
Simulation Models of Energy Cables in SPICE
Authors: Balaji Uma
Published: December 2019

Accurate modeling of cables is important to study the behavior of high frequency disturbances in power converter systems. This paper reviews and compares two popular methodologies to model energy cables – an improved per unit length parameters based model and a Laplace SPICE element based model. The two models presented take into account the frequency dependence of the parameters of the cable. A ladder network is used for this purpose in the per unit length based model. The Laplace SPICE element model is generated from from a rational function approximation for the admittance parameters that are frequency dependant. The rational function approximation is obtained using a well known vector fitting algorithm.  The time and frequency domain solutions of a two wire energy cable, obtained from the two models, agree well.
Evaluation of Synchronization and MPPT algorithms in a DFIG Wind Turbine Controlled by an Indirect Matrix Converter
Authors: Khajeh Ahmad , Ghazi Reza , Hosseini Abardeh Mohamad , Oukati Sadegh Mahmoud
Published: December 2019

Most of generators utilized in wind turbines are the Doubly-Fed Induction Generator (DFIG). Indirect matrix converter (IMC) is a candidate for substituting the traditional back-to-back converter in the future due to advantages gained by elimination of electrolytic capacitor. Starting DFIG wind turbines and synchronizing to the grid is a challenge in practice because of large inrush currents that could damage switches. Synchronizing the DFIG wind turbine controlled by the IMC is presented in this paper. Also, maximum power point tracking algorithm performance of this configuration is examined. A laboratory scale prototype of the proposed configuration is built. Experimental results have confirmed effectiveness of this configuration.
Harmonic Reduction in Single Boost Converter Fed DC Motor with EMI Input Filter
Authors: Sivakumar A. , Muthamizhan T.
Published: December 2019

DC motor drive system supplied by AC/DC rectifier topology considered as a nonlinear load. It produces harmonic distortions and EMI noise effects in the power systems. In this paper deals with the reduction of supply current harmonics and EMI noise generated by the power electronics converter in the DC motor drive using FFT analysis. The single boost converter along with EMI input filter is proposed in this system to investigate the harmonic reduction in the DC motor drive. The single boost converter fed DC motor drive is modeled and simulated using MATLAB/Simulink software. The simulation results show better agreement with the proposed system.
Territórios da financeirização urbana
Authors: Sanfelici Daniel De Mello
Published: December 2019

Resenha do livro "From boom to bubble: how finance built the new Chicago", de Rachel Weber.
Trajetória e a participação dos complexos convectivos de mesoescala nas chuvas de outubro: estudo de caso
Authors: Borsato Victor Da Assunção , Massoquim Nair Gloria
Published: December 2019

A cidade de Campo Mourão PR, localizada nas proximidades do trópico de Capricórnio, é influenciada pela alternância de massas de ares de baixa e de alta pressão atmosférica. Os contrastes na pressão e nos sistemas atmosféricos são mais evidentes na primavera, estação que compreende os meses de transição do inverno para o verão, como é o caso do mês de outubro. Esse mês marca a volta de episódios de chuvas convectivas, características do verão, embora ainda prevaleça a atuação dos sistemas frontais. O mês de outubro também é marcado por episódios tempestuosos devido à alternância da participação das massas de ares de baixa e de alta pressão, das Frontogêneses, das manifestações dos Complexos Convectivos de Mesoescala (CCM) e das Correntes de Jatos de Baixo Nível (JBN). Para essa região, a pluviosidade interanual é irregular, porém, em outubro de 2017 registraram-se 396,6mm, em Campo Mourão. Para investigar a gêneses desse elevado volume, estudou-se a participação das massas de ares, dos sistemas frontais, dos CCM e também a participação da Correntes de Jatos de Baixo Nível. Verificou-se que as chuvas, consequências da atuação dos CCM, foram próximas a 30%, e as interações entre a umidade trazida pelo JBN, a evolução das ciclogêneses, a expansão e atuação da massa Tropical continental dinamizam os temporais.
O processo de consolidação da centralidade regional de Dourados-MS na rede urbana: uma contribuição para a análise de uma cidade média
Authors: Calixto Maria José Martinelli Silva
Published: December 2019

Neste texto, partimos de um esforço em reconstituir o processo de consolidação da condição regional de Dourados-MS, tomando por base sua inserção na rede urbana, buscando oferecer uma contribuição para a apreensão das mudanças nos papeis que os centros urbanos não metropolitanos, ou as cidades médias, desempenham. Vale referenciar que, tendo em vista a premissa de que as dinâmicas processuais são determinadas pelas relações sociais, a posição de centralidade (entendida como construção social, portanto, ligada à ideia de movimento) coloca-se como condição e, sendo condição, está sujeita a mudanças no decorrer do tempo, ou seja, possui uma duração espaço-temporal. No caso de Dourados, deve-se considerar não apenas a sua condição ou nível de centralidade, na rede urbana do sul do estado de Mato Grosso Sul, mas também sua posição, haja vista que a própria divisão territorial do trabalho implica em uma complexidade funcional dos centros urbanos.
Henri Lefebvre: totalidade, radicalidade e dialética espacial
Authors: Volochko Danilo
Published: December 2019

O presente artigo trata a noção de totalidade a partir do pensamento de Henri Lefebvre, buscando possíveis articulações desta noção com a análise geográfica da produção do espaço urbano. O caminho percorrido por esta reflexão envolveu a hipótese de que o espaço urbano e a sociedade urbana carregariam a possibilidade teórica e prática de realização de uma totalidade humana, desafiando-nos a compreender aspectos filosóficos, analíticos e espaciais da construção de uma noção de totalidade aberta, movente e dialética. Como desenvolvimento e como resultado da discussão, assinalamos que a totalidade, na perspectiva lefebvriana, pode ser pensada nos termos da tríade totalidade-negatividade-radicalidade, e que esta tríade, por sua vez, pode compor a construção de novos horizontes para a vida urbana.
Habitar como horizonte utópico
Authors: Pádua Rafael Faleiros de
Published: December 2019

O artigo busca apresentar o habitar como uma noção filosófica que ilumina os conteúdos da vida urbana e revela as suas contradições. Essa noção é pensada enquanto elemento fundamental da produção filosófica do homem, onde tem lugar a necessidade radical de apropriação do espaço para a reprodução da vida. No capitalismo, o espaço se torna mercadoria e objeto de estratégias econômicas, o que reduz o habitar a uma função, o habitat. Nesse contexto, o desafio prático e teórico é recolocar o habitar como possibilidade utópica a partir da realidade funcionalizada do habitat.
Biomarkers of Inflammation and Fibrosis in Kawasaki Disease Patients Years After Initial Presentation With Low Ejection Fraction
Authors: Hoshino Shinsuke , Shimizu Chisato , Jain Sonia , He Feng , Tremoulet Adriana H. , Burns Jane C.
Published: December 2019

Background

Coronary artery aneurysms and myocarditis are well‐recognized complications of Kawasaki disease (
KD
) but no systematic evaluation of the consequences of myocarditis has been performed in the subset presenting with low ejection fraction (
EF
). We postulated that more severe myocardial inflammation as evidenced by low
EF
during the acute phase could lead to late myocardial fibrosis.

Methods and Results

We measured the carboxyterminal propeptide of procollagen type I (
PIPC
), soluble suppressor of tumorigenicity 2, galectin‐3 (Gal‐3), growth‐differentiation factor‐15, and calprotectin by
ELISA
in late convalescent blood samples from 16
KD
patients who had an
EF
≤55% on their initial echocardiogram. Results were compared with samples from sex‐ and age‐matched
KD
patients with initial
EF
>60%. In the univariate analysis, the median Gal‐3 and
PIPC
levels in the low
EF
group were significantly higher than those in the normal
EF
group (Gal‐3: low
EF
6.216 versus normal
EF
4.976 mg/dL
P
=0.038,
PIPC
: low
EF
427.4 versus normal
EF
265.2 mg/dL,
P
=0.01). In a multivariable analysis, there were significant differences for Gal‐3 and
PIPC
levels between the low and normal
EF
groups, adjusting for age, sex, and worst z score.

Conclusions

Convalescent
KD
patients with a history of low
EF
during the acute illness had significantly elevated levels of Gal‐3 and
PIPC
when compared with matched‐control
KD
patients with normal
EF
. These findings raise concern for myocardial fibrosis as a potential late sequela of the more severe myocarditis experienced by a subset of
KD
patients during the acute phase.
Defending the Rule-based Trading Regime: The Multilateral Trading System at Risk and Required Responses
Authors: Kimura Fukunari
Published: December 2019

The current trade turmoil is not limited to negative economic effects stemming from the series of recent trade measures erected by the United States as part of the escalating U.S.–China trade war. The more serious issue that will unfold in the middle to long term is the potential collapse of the rule-based trading regime. The weakening of the multilateral trading system centered by the World Trade Organization (WTO) seems to continue. East Asia has been one of the largest beneficiaries of the rule-based trading regime in its course of extending and deepening international production networks and must now take proactive moves to defend and preserve this stable economic environment. Two crucial tasks in the preservation of the WTO are efforts to maintain the functionality of the dispute settlement mechanism and the revival of the WTO as a forum for future trade negotiations. At the same time, East Asia must develop a network of mega–free trade agreements (FTAs) to partially supplement a possible loss of the multilateral framework.
Women's Underrepresentation in the U.S. Congress
Authors: Sanbonmatsu Kira
Published: December 2019

Women's elective office-holding stands at an all-time high in the United States. Yet women are far from parity. This underrepresentation is surprising given that more women than men vote. Gender–as a feature of both society and politics–has always worked alongside race to determine which groups possess the formal and informal resources and opportunities critical for winning elective office. But how gender connects to office-holding is not fixed; instead, women's access to office has been shaped by changes in law, policy, and social roles, as well as the activities and strategies of social movement actors, political parties, and organizations. In the contemporary period, data from the Center for American Women and Politics reveal that while women are a growing share of Democratic officeholders, they are a declining share of Republican officeholders. Thus, in an era of heightened partisan polarization, women's situation as candidates increasingly depends on party.
The New Competition in Multilateral Norm-Setting: Transnational Feminists & the Illiberal Backlash
Authors: Goetz Anne Marie
Published: December 2019

Global norm-setting to advance women's rights has historically been a fertile area for feminist activism. These efforts in multilateral institutions have also, however, attracted a transnationally coordinated backlash. Initially spearheaded by the Vatican, the right-wing backlash has consolidated into a curious coalition that now includes authoritarian and right-wing populist regimes and bridges significant differences of religious belief, regime type, and ideology. Hostility to feminism has proven to be a valuable point of connection between interests that otherwise have little in common. Some tensions between feminist groups have been exploited by right-wing interests, in particular over sex workers' rights and the use of technology to alter the interpretation and experience of sexuality, reproduction, and gender (transgender issues, surrogacy, sex-selective abortion, and sexuality and disability). This essay reviews a recent instance of right-wing coordination, seen in the nearly successful effort to derail the 2019 meeting of the UN Commission on the Status of Women. It examines the strategic responses of transnational feminist movements to this backlash in multilateral institutions, including their exploration of new transnational policy issues and experimentation with hybrid transnational spaces.