Indonesian Journal of Electrical Engineering and Informatics (IJEEI)
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A Simple Method to Control The Excitation Angle for Switched Reluctance Motor
Get PDFA switched reluctance motor (SRM) has been an alternative solution for electric drives because of its benefit features. The use of such a motor in electric vehicles (EVs) or hybrid electric vehicles (HEVs) requires a control strategy that is capable to develop high torque. SRMs are commonly available in the market with rotor position detectors embedded inside. Problems will appear when such detectors are not symmetrically installed because most of SRM control strategies are commonly based on them. Inaccurate pulses will be generated by the control circuit which finally takes effect on phase current commutation or the beginning of the excitation which is not on proper angle. The use of such detectors is just capable to give information of rotor position in common angles. Improvement for such problems can be done by generating pulses related to the rotor position in smooth angles. In this paper, a control strategy to produce excitation signals with proper angles for SRM stator winding is proposed. By using input capture facility that is commonly available in embedded system, excitation angles can be controlled precisely because a large number of pulses can be produced by the system. Accuracy level of this strategy is determined by TIMER period of embedded system and speed of SRM. To verify the analysis, laboratory experiments were done. They show that the proposed control strategy is capable to rotate the motor with better performance
Voltage Rise Problem in Distribution Networks with Distributed Generation: A Review of Technologies, Impact and Mitigation Approaches
Get PDFEnergy demand has constantly been on the rise due to aggressive industrialization and civilization. This rise in energy demand results in the massive penetration of distributed generation (DG) in the distribution network (DN) which has been a holistic approach to enhance the capacity of distribution networks. However, this has led to a number of issues in the low voltage network, one of which is the voltage rise problem. This happens when generation exceeds demand thereby causing reverse power flow and consequently leading to overvoltage. A number of methods have been discussed in the literature to overcome this challenge ranging from network augmentation to active management of the distribution networks. This paper discusses the issue of voltage rise problem and its impact on distribution networks with high amounts of distributed energy resources (DERs). It presents different DG technologies such as those based on conventional and unconventional resources and other DERs such as battery storage systems and fuel cells. The study provides a comprehensive overview of approaches employed to curtail the issue of voltage increase at the point of common coupling (PCC), which includes strategies based on the network reinforcement methodology and the active distribution network management. A techno-economic comparison is then introduced in the paper to ascertain the similarities and dissimilarities of different mitigation approaches based on the technology involved, ease of deployment, cost implication, and their pros and cons. The paper provides insights into directions for future research in mitigating the impact of voltage rise presented by grid-connected DGs without limiting their increased penetration in the existing power grid
Towards a better understanding of the Organizational Characteristics that affect Acceptance of Big Data Platforms for Academic Teaching
Get PDFIn today's era of information, data has been growing at an exponential rate to become big data, and it needs platforms to allow users to govern, access, deliver, analyze, and use these huge databases. Academics in higher education need to utilize these platforms in teaching to enrich and empower the educational experience of their students of these institutions. The purpose of the current study is to investigate the impact of organizational characteristics on the acceptance of big data platforms for academic teaching among higher education institutes in Malaysia. 143 respondents participated to examine the effect of organizational characteristics (Management Drive, Bandwagon Pressure, and Training) on the acceptance of big data platforms for academic teaching. Besides, examining the moderating role of task technology fit. The results illustrate that management drive, bandwagon pressure has a significant impact on the acceptance, with an insignificant impact of training on the acceptance. However, task technology fit has not moderated any of the proposed relationships. This study would give insight for the higher education institutes managements to improve their academics acceptance of the big data platforms in teaching and therefore drive them to use the aforementioned platforms
Ultra-wideband bandpass filter with notch band based on quadratic Koch Island structure
Get PDFAn ultra-wideband bandpass filter with a notch band centered at 7.2 GHz is proposed to remove the interference caused by satellite communication signal coexciting within the ultra wide band. The filter comprises of two seperated quadratic koch island structures connected to the main transmission line to generate the notch band at the desired frequency. The designed ultra wide bandpass filter passes frequencies from 3.09 GHz to 10.61 GHz with a notch band from 7.12 to 7.46 GHz centered at 7.2 GHz and with a rejection level of 21.3 dB.The resonant frequency and bandwidth of the notch can be varied by the variation in the physical parameter of the filter. The proposed filter is fabricated, tested and compared with simulated results
Classification and Grip of Occluded Objects
Get PDFThe present paper exposes a system for detection, classification, and grip of occluded objects by machine vision, artificial intelligence, and an anthropomorphic robot, to generate a solution for the subjection of elements that present occlusions. The deep learning algorithm used is based on Convolutional Neural Networks (CNN), specifically Fast R-CNN (Fast Region-Based CNN) and DAG-CNN (Directed Acyclic Graph CNN) for pattern recognition, the three-dimensional information of the environment was collected through Kinect V1, and tests simulations by the tool VRML. A sequence of detection, classification, and grip was programmed to determine which elements present occlusions and which type of tool generates the occlusion. According to the user's requirements, the desired elements are delivered (occluded or not), and the unwanted elements are removed. It was possible to develop a program with 88.89% accuracy in gripping and delivering occluded objects using networks Fast R-CNN and DAG-CNN with achieving of 70.9% and 96.2% accuracy respectively, detecting elements without occlusions for the first net and classifying the objects into five tools (Scalpel, Scissor, Screwdriver, Spanner, and Pliers), with the second net. The grip of occluded objects requires accurate detection of the element located at the top of the pile of objects to remove it without affecting the rest of the environment. Additionally, the detection process requires that a part of the occluded tool be visible to determine the existence of occlusions in the stac
Maximum Power Point Box (MPPB) Design to Advance BIPV Installations on Residential Properties
Get PDFPhotovoltaic installations on residential properties gained high momentums during the past decade. Building integrated photovoltaic materials are well developed and has the potential to advance the photovoltaic systems installations on residential and commercial buildings. One of the main limitations on residential system is the utility allowable AC power generation. The installation of BIPV on houses offer numerous orientation and tilts of the PV system which ensure sun energy is harvested for wider timeframe. The different orientations and tilts reflect changes in the generate output power. The available residential inverters have one of two MPPTs which limit the orientation and tilts of the system to a maximum of two options per inverter. Adding more inverters will add cost burden on the system, exceed the utility maximum allowable AC power generation, and additional inverters will not work at rated power throughout the day. The works in this paper include the detail design of a maximum power point box (MPPB) that harvest the sun energy for different orientations and tilts, manage and regulate the DC Bus Bar voltage level as well as generated DC power prior the inverter input terminal. The process is governed by an input from the inverter using an industrial communication protocol such as MODBUS. The aim of the box is to reduce the number of inverters required for maximum power generation while maintaining the maximum AC limits set the by utilities. The paper includes the details design with the proposed circuit along its optimum logics. Case study is also includedPhotovoltaic installations on residential properties gained high momentums during the past decade. Building integrated photovoltaic materials are well developed and has the potential to advance the photovoltaic systems installations on residential and commercial buildings. One of the main limitations on residential system is the utility allowable AC power generation. The installation of BIPV on houses offer numerous orientation and tilts of the PV system which ensure sun energy is harvested for wider timeframe. The different orientations and tilts reflect changes in the generate output power. The available residential inverters have one of two MPPTs which limit the orientation and tilts of the system to a maximum of two options per inverter. Adding more inverters will add cost burden on the system, exceed the utility maximum allowable AC power generation, and additional inverters will not work at rated power throughout the day. The works in this paper include the detail design of a maximum power point box (MPPB) that harvest the sun energy for different orientations and tilts, manage and regulate the DC Bus Bar voltage level as well as generated DC power prior the inverter input terminal. The process is governed by an input from the inverter using an industrial communication protocol such as MODBUS. The aim of the box is to reduce the number of inverters required for maximum power generation while maintaining the maximum AC limits set the by utilities. The paper includes the details design with the proposed circuit along its optimum logics. Case study is also include
Hybrid Petri nets-based Flow modeling and application on hybrid system.
Get PDFFlow management is necessary in several application areas, in the optimization of industrial production lines, in IT to manage data flows and in the automation of industrial systems. Physical systems in general consist of continuous processes interacting with discrete processes forming a hybrid dynamic system constituted by continuous dynamic type models and discrete events. The application of the hybrid Petri nets tool in the modeling, study and performance evaluation of these systems helps to analyze the dynamic properties by acting on the parameters and the structure of the models in order to evaluate their behavior. This work is focused on the application of this tool to model a material flow management system between a rotary kiln and a clinker cooler in a production line (cement process). The implementation of the modeling and the analysis of the results obtained by simulation on a software platform (Visual Object Net ++), aims to study industrial processes with mathematical tools and to follow their behavior on software, this allows us an optimal analysis of complex systems in dangerous environments, and to try practical and effective solutions by simple means before moving on to the implementation and programming of actions that require more expensive means
Complete Load Analysis of a residential Hall of CUET in Bangladesh and Design of a Roof Top Solar PV System
Get PDFIn this paper a complete load analysis of a residential hall of CUET in Bangladesh is performed, and a roof top solar PV System is designed. At first the load of this building is estimated, and a complete daily load profile is developed. Using the estimated load profile, the size of solar array and other components are estimated. After that, a complete system is designed connecting the components of estimated rating and size. Additionally, an optimization of system is performed using HOMER. Furthermore, the dynamic response of the proposed system is analyzed using Simulink, MATLAB and based on this response essential control and protection schemes are incorporated with the system. The effectiveness of these schemes is also verified by MATLAB simulation
Paratransit Trip Data Collection System with Smartphone GPS and REST Web Service in Malang, Indonesia
Get PDFParatransit in Malang has its own irregular characteristics, same as in other cities in the world. It is tough to recognize the exact operational time, availability, and estimated travel time when using paratransit. The information about paratransit can be only obtained by making predictions due to its irregular characteristics. This research examined the importance of a system that can collect paratransit travel data as a basis for making predictions. Therefore, this research proposes the design of a paratransit travel data collection system by utilizing smartphone GPS and REST web service. To determine the position of the paratransit, the researchers used the concept of circle-based geofencing which is called pseudo-stop. The initial results obtained from the experiment indicated the influence of tracking intervals and radius of pseudo-stop on effectiveness and efficiency of the system. The shorter the tracking interval, the higher the tendency of the pseudo-stop radius value to decrease, resulting in decreased effectiveness and increased efficiency. Otherwise, the wider the tracking interval, the higher the tendency of the pseudo-stop radius value to be greater, resulting in increased effectiveness and decreased efficiency. In spite of periodically accessing location providers, the energy usage is quite low
Synthesis and Characterization of Ba0.6Sr0.4Fe12O19/LaMnO3 Composites as Microwave Absorbers
Get PDFThe synthesis and characterization of Ba0.6Sr0.4Fe12O19/LaMnO3 composite material has been successfully carried out by mechanical alloying method using high energy milling. Crystal structure and surface morphology were characterized using x-ray diffraction and scanning electron microscopy. While the value of magnetization and the ability to absorb microwaves, vibrating sample magnetization and vector network analyzing were used, respectively. With variations in weight, does not change the crystal structure. The Ba0.6Sr0.4Fe12O19phase has a hexagonal structure and the LaMnO3 phase has an orthorhombic structure. Surface morphology has a heterogeneous size in the range of 200-450 nm with the form of platelets. The composite material Ba0.6Sr0.4Fe12O19/LaMnO3 is a hard-soft magnetic material with a magnetic saturation of Ms ~ 46.83 emu/g, Mr ~ 28.8 emu/g, and a coercive field of Hc ~ 3.88 kOe. The minimum reflection loss value is – 13.0 dB at 11.2 GHz frequency and 1.52 GHz bandwidth