Design and implementation of a dual-input single-output photovoltaic converter

In many solar inverters, a dc/dc converter is mainly located between the solar arrays and the inverter. This study presents an enhanced maximum power point tracking (MPPT) algorithm for photovoltaic (PV) systems that drives solar array voltages to track a reference value and decreases fluctuations and oscillations in PV voltage. Different from the previously presented methods, a novel MPPT method is proposed that ensures tracking accuracy by considering output voltage in addition to input voltage and currents. The proposed method detects dI/dV variations, compares the output voltage with the desired reference to shift operation mode and refreshes step size. The digital filtering, enhanced PI, and perturb-and-observe (P&O) tracking features of the proposed MPPT method make it robust to mitigate source fluctuations and sensitivity to partial shading based oscillations. In order to validate the success of the proposed method, a test rig has been installed with dual boost converters. The performance improvements have been verified by both simulation and experimental results that are compared to InCon and P&O MPPT methods. It is also confirmed by experimental results that the proposed MPPT method provides robust control capability in terms of tracking the reference voltage and rejecting the effects of various shading situations on solar arrays

Internet of Things Applications as Energy Internet in Smart Grids and Smart Environments

Energy Internet (EI) has been recently introduced as a new concept, which aims to evolve smart grids by integrating several energy forms into an extremely flexible and effective grid. In this paper, we have comprehensively analyzed Internet of Things (IoT) applications enabled for smart grids and smart environments, such as smart cities, smart homes, smart metering, and energy management infrastructures to investigate the development of the EI based IoT applications. These applications are promising key areas of the EI concept, since the IoT is considered one of the most important driving factors of the EI. Moreover, we discussed the challenges, open issues, and future research opportunities for the EI concept based on IoT applications and addressed some important research areas

Thermal, microstructural and spectroscopic properties of the fluorotelluride optical glasses

Telürit esaslı cam malzemeler, katıhal lazer malzemelerinden lazer malzemesi olarak, fiber optik yükselticilerinde ve doğrusal olmayan optik camlarda kullanılan önemli fotonik malzemelerdir. Bu nedenle, telürit camlarının spektroskopik özellikleri deneysel araştırmacıların başlıca araştırma konusu haline gelmiştir. Telürit camlarının en önemli özellikleri olarak, geniş iletim bölgesine (0.35- 5 µm), en yaygın oksitli camlar arasında en düşük fonon enerjisine, yüksek kırılma indisine, düşük erime sıcaklığına, yüksek dielektrik sabitine sahip olmasıdır. Ayrıca, yakın morötesinden orta kızılaltı bölgeye kadar, geniş bir geçirgenlik bölgesine sahiptir. Bu çalışmada fotonik malzeme olarak kullanılma potansiyeli olan (1-x)TeO2-xPbF2 (x=0.10, 0.15 ve 0.25 mol) optik cam malzemelerin sentezi gerçekleştirilmiştir. Bu malzemelerin termal, mikroyapı ve spektroskopik özellikleri incelenmiştir. Cam geçiş, kristallenme ve erime sıcaklıkları her bir kompozisyon için 10 °C/dak ısıtma hızı ile ölçülen DTA eğrileri kullanılarak belirlenmiştir. Kompozisyonun ve kristallenmenin bu camların yapısına etkisi X-ışını kırınımı, (XRD), Taramalı elektron mikroskopu, (SEM), Optik mikroskop (OM) ve Raman spektroskopisi (FT-IR Raman) kullanılarak incelenmiştir. Bu cam malzemeler, fiber optik iletişim ağlarında optik yükseltici olarak kullanılabilme potansiyelini araştırmak amacıyla, bir nadir toprak iyonu olan tulyum iyonu ile katkılanmıştır. Katkılanan malzemelerin (yakın kızılaltı) bölgesindeki ışıma özelliklerine tulyum iyonu konsantrasyonu etkisi lazer spektroskopisi kullanılarak incelenmiştir. 0.2 mol Tm3+ katkılı cam malzemenin (0.9TeO2-0.1PbF2) en yüksek ışınım kuvantum verimine sahip olması nedeniyle 1470 nm dalga boyunda fiber optik yükseltici olarak kullanılma potansiyeline sahip olduğu görülmektedir. Anahtar kelimeler: Fotonik malzeme, lazer yükseltici, telürit, raman spektroskopi.Tellurite based glasses with doped rare-earth ions have attracted for the structural study and from the technological and academic point of view. Recently, considerable effort has been devoted to dielectric materials and design for optical fibers, waveguide devices and optical fiber amplifiers to improve the telecommunication sysytems. In that case, many researches have been focused on to the producing new photonic devices which have low-loss optical waveguides. Er3+ and Tm3+-doped tellurite photonic materials are potential candidate material for the applications in fiber-optic amplifier and fiber laser devices. Therefore, developing more stable tellurite based materials are important for applications as a technological devices. In this research, transparent tellurite glasses were prepared by using reagent TeO2, and PbF2. The batch materials (7 g) were well mixed in a platinum crucible and melted at 800oC for 60 min in the electrically heated furnace in air atmosphere. The glass melts were than removed from the furnace at 800oC and air-quenched by pressing between two rectangular graphite slabs at room temperature. The density of each glass sample was measured by using Archimede?s principle with distilled water as the immersion liquid (Kabalci vd. 2004). The measured density was about 6.3 g/cm3 for the glass sample. A Rigaku Thermoflex Differantial Thermal analyzer equipped with a PTC-10A temperature control unit was used in order to determine the thermal parameters. The samples of about 20 mg were heated it heating at heating rate of  10oC/min in a platinum crucible and using the same amount of Al2O3 as the reference material in the temperature range between 20 and 600oC. The Tg temperature is selected as mid-point between the onset and the minimum temperature. The Tc and Tg temperatures were measured at the onset crystallization, and the Tp temperature was measured at the peak of crystallization. The microstructural characterization of the as-cast and annealed glass samples were carried out using X-ray diffraction (XRD), and scanning electron microscopy (SEM), optical microscope and Raman spectrophotometer techniques. The x-ray diffraction investigations were carried out in a PhilipsTM Model PW3710 using CuKa radiation at 40 kV and 40 mV settings in the 2q range from 10 to 90o. The crystallized phases were identified by comparing the peak positions and intensities with those in the JCPDS (Joint Committee on Power Diffraction Standards) data files. Scanning electron microscope (SEM) investigations were conducted in a JEOLTM Model JSM-T330 operated at 25 kV, and JEOL JSM 5410 scanning microscope, linked with a Zmax 30 Boron-up light element energy dispersive spectrometer (EDS) detector. For the SEM investigations, optical mount specimens were prepared using standard metallographic techniques followed by chemical etching in a HF solution (5%) for a minute. The etched optical samples were coated with golden. The Nikon Eclipse L150 Optical Microscope (OM) were used for microscopic observations and to obtain optical micrographs of the surfaces. The magnification levels (combined with eye-piece magnification) are, 50X, 100X, and 200X. Its magnification can be further enhanced by taking a digital image and zooming it with any image software. The Raman spectra were measured with a digilab FTS 7000 spectrophotometer in the spectral range 0-1000 cm-1. The glass samples were excited with a Nd:YAG laser at 1064 nm with power of about 500 mW. The digital intensity data were recorded at intervals 1 cm-1, with 64 scans, and at resolution 8 cm-1 with a Ge detector cooled to liquid nitrogen temperature. In fluorescence measurements, samples were excited with a 25-mW continuous-wave diode laser at 785 nm. After passing through a 0.5-m Czerny-Turner type monochromator, the fluorescence signal was detected with a PbS detector and amplified in two stages by using a preamplifier and a lock-in amplifier. We also have investigated the variation of the luminescence strengths as a function of Tm3+ ion concentration in a new type of Tm3+ doped tellurite glass. Tm3+ doped glasses have two emission bands that peak around 1470 nm and 1800 nm in the near infrared. Keywords: Photonic material, laser amplifier, raman spectroscopy

Determination of the number of Vertical Axis Wind Turbine blades based on power spectrum

Technology of wind exploitation has been applied widely all over the world and has already reached the level in which manufacturers want to maximize the yield with the minimum investment outlays. The main objective of this paper is the determination of the optimal number of blades in the Cup-Bladed Vertical Axis Wind Turbine. Optimizing the size of the Vertical Axis Wind Turbine allows the reduction of costs. The maximum power of the rotor is selected as the performance target. The optimum number of Vertical Axis Wind Turbine blades evaluation is based on analysis of a single blade simulation and its superposition for the whole rotor. The simulation of working blade was done in MatLab environment. Power spectrum graphs were prepared and compared throughout superposition of individual blades in the Vertical Axis Wind Turbine rotor. The major result of this research is the Vertical Axis Wind Turbine power characteristic. On the basis of the analysis of the power spectra, optimum number of the blades was specified for the analysed rotor. Power spectrum analysis of wind turbine enabled the specification of the optimal number of blades, and can be used regarding investment outlays and power output of the Vertical Axis Wind Turbine

Half‐Cauchy and Power Cauchy Distributions: Ordinary Differential Equations

In this chapter, homogenous ordinary differential equations (ODES) of different orders were obtained for the probability density function, quantile function, survival function inverse survival function, hazard function and reversed hazard functions of half‐Cauchy and power Cauchy distributions. This is possible since the aforementioned probability functions are differentiable. Differentiation and modified product rule were used to obtain the required ordinary differential equations, whose solutions are the respective probability functions. The different conditions necessary for the existence of the ODEs were obtained and it is almost in consistent with the support that defined the various probability functions considered. The parameters that defined each distribution greatly affect the nature of the ODEs obtained. This method provides new ways of classifying and approximating other probability distributions apart from half‐Cauchy and power Cauchy distributions considered in this chapter. In addition, the result of the quantile function can be compared with quantile approximation using the quantile mechanics

From smart grid to internet of energy

From Smart Grid to Internet of Energy covers novel and emerging metering and monitoring technologies, communication systems, and technologies in smart grid areas to present a valuable reference for readers from various engineering backgrounds. Considering relevant topics on the essentials of smart grids and emerging wireless communication systems, such as IEEE 802.15.4 based novel technologies, cognitive radio networks and Internet of Energy, this book offers a discussion on the emerging trends and research direction for communication technologies. The book includes research concepts and visualization of smart grids and related communication technologies, making it a useful book for practicing network engineers

Design and Implementation of Wireless Energy Monitoring System for Smart Grids

Measurement and remote monitoring process are very important processes for smart grids. In this study, design and implementation of smart metering system and remote monitoring system for smart grids are proposed. Designed smart metering system is capable of measuring quantities of DC current, DC voltage and power values. In order to convert measured quantities into suitable formats for transmitting wirelessly, a microcontroller-based signal processing system is designed and is implemented. Afterwards, measured voltage and current values are transmitted to receiver unit entitled as energy monitoring center by utilizing wireless communication methods. The communication infrastructure of the proposed system is conducted by ZigBee protocol due to its offered advantages such as being low cost, easy programming and low power consumption. Moreover, an interface is designed by C# programming language in Visual Stuio.Net to monitor received information by energy monitoring center in a real time. The conducted studies showed that the proposed smart metering and remote monitoring system could be efficiently utilized to observe current, voltage and power values of photovoltaic panels

A Measurement and Power Line Communication System Design for Renewable Smart Grids

WOS: 000326683300004The data communication over the electric power lines can be managed easily and economically since the grid connections are already spread around all over the world. This paper investigates the applicability of Power Line Communication (PLC) in an energy generation system that is based on photovoltaic (PV) panels with the modeling study in Matlab/Simulink. The Simulink model covers the designed PV panels, boost converter with Perturb and Observe (P&O) control algorithm, full bridge inverter, and the binary phase shift keying (BPSK) modem that is utilized to transfer the measured data over the power lines. This study proposes a novel method to use the electrical power lines not only for carrying the line voltage but also to transmit the measurements of the renewable energy generation plants. Hence, it is aimed at minimizing the additional monitoring costs such as SCADA, Ethernet-based or GSM based systems by using the proposed technique. Although this study is performed with solar power plants, the proposed model can be applied to other renewable generation systems. Consequently, the usage of the proposed technique instead of SCADA or Ethernet-based systems eliminates additional monitoring costs

Digital Transformation of Microgrids: A Review of Design, Operation, Optimization, and Cybersecurity

This paper provides a comprehensive review of the future digitalization of microgrids to meet the increasing energy demand. It begins with an overview of the background of microgrids, including their components and configurations, control and management strategies, and optimization techniques. It then discusses the key digital technologies that can be used to improve the performance of microgrids, including distributed energy resources management systems, the Internet of Things, big data analytics, blockchain technology, artificial intelligence, digital twin technology, cloud computing, and augmented reality. The paper also highlights the importance of cybersecurity in microgrids, identifying the potential security vulnerabilities and threats to microgrid cybersecurity, as well as strategies for addressing these challenges. Finally, the paper discusses the barriers and challenges regarding the digitalization of microgrids, including technical complexity, high implementation costs, regulatory barriers, data privacy and security concerns, lack of standardization, interoperability issues, limited technical expertise, and integration with the main grid. Overall, this paper demonstrates the significant potential for digital technologies to transform the future of microgrids. By leveraging advanced technologies and implementing effective cybersecurity measures, microgrids can become more efficient, reliable, and resilient, enabling them to meet the growing demand for energy and contribute to a sustainable energy future

A survey on smart metering and smart grid communication

WOS: 000370456000023The smart metering and communication methods used in smart grid are being extensively studied owing to widespread applications of smart grid. Although the monitoring and control processes are widely used in industrial systems, the energy management requirements at both service supplier and consumer side for individuals promoted the evolution of smart grid. In this paper, it is aimed to disclose in a clear and clean way that what smart grid is and what kind of communication methods are used. All components of a smart grid are introduced in a logical way to facilitate the understanding, and communication methods are presented regarding to their improvements, advantages, and lacking feature. The developing generation, transmission, distribution and customer appliances are surveyed in terms of smart grid integration. The communication technologies are introduced as wireline and wireless classification where the key features are also tabulated. The security requirements of hardware and software in a smart grid are presented according to their cyber and physical structures. (C) 2015 Elsevier Ltd. All rights reserved