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Showing records 133 to 155 of 155. [First] Page: 1 3 4 5 6 7 Last
A Statistical Framework for Automatic Leakage Detection in Smart Water and Gas Grids
Marco Fagiani, Stefano Squartini, Leonardo Gabrielli, Marco Severini, Francesco Piazza
January 31, 2019 (v1)
Keywords: automatic leakage detection, gas grids, Gaussian mixture model, hidden Markov models, novelty detection, one-class support vector machine, smart water
In the last few years, due to the technological improvement of advanced metering infrastructures, water and natural gas grids can be regarded as smart-grids, similarly to power ones. However, considering the number of studies related to the application of computational intelligence to distribution grids, the gap between power grids and water/gas grids is notably wide. For this purpose, in this paper, a framework for leakage identification is presented. The framework is composed of three sections aimed at the extraction and the selection of features and at the detection of leakages. A variation of the Sequential Feature Selection (SFS) algorithm is used to select the best performing features within a set, including, also, innovative temporal ones. The leakage identification is based on novelty detection and exploits the characterization of a normality model. Three statistical approaches, The Gaussian Mixture Model (GMM), Hidden Markov Model (HMM) and One-Class Support Vector Machine (OC... [more]
Promoting Effect of Inorganic Alkali on Carbon Dioxide Adsorption in Amine-Modified MCM-41
Yang Teng, Lijiao Li, Gang Xu, Kai Zhang, Kaixi Li
January 31, 2019 (v1)
Keywords: alkali amounts, amine-modified MCM-41, CO2 adsorption, inorganic alkali
Three kinds of inorganic alkali are introduced into tetraethylenepentamine (TEPA) and polyethyleneimine (PEI)-modified MCM-41 as the CO₂ adsorbents. X-ray diffraction, N₂ adsorption, fourier-transform infrared and thermo gravimetric analysis are used to characterize the surface structures and the thermal stability of adsorbents. Chemical titration method is used to measure the alkali amounts of adsorbents. Thermo-gravimetric analysis with 10% CO₂/90% N₂ as the simulated flue gas is used to test the CO₂ adsorption performance of adsorbents. The results show that all three kinds of inorganic alkali-containing adsorbents exhibit higher CO₂ adsorption capability than traditional TEPA and PEI modified samples. Ca(OH)₂ and PEI modified samples exhibit the highest adsorption capacity and recyclable property. The introduction of inorganic alkali changes the chemical adsorption mechanism between CO₂ and adsorbent surface due to the increased hydroxyl groups. The CO₂ adsorption capacities have a... [more]
Capacitor Current Feedback-Based Active Resonance Damping Strategies for Digitally-Controlled Inductive-Capacitive-Inductive-Filtered Grid-Connected Inverters
Iman Lorzadeh, Hossein Askarian Abyaneh, Mehdi Savaghebi, Alireza Bakhshai, Josep M. Guerrero
January 30, 2019 (v1)
Keywords: active resonance damping, current control, discrete-time domain, grid-connected inverter, Inductive-capacitive-inductive (LCL)-filter
Inductive-capacitive-inductive (LCL)-type line filters are widely used in grid-connected voltage source inverters (VSIs), since they can provide substantially improved attenuation of switching harmonics in currents injected into the grid with lower cost, weight and power losses than their L-type counterparts. However, the inclusion of third order LCL network complicates the current control design regarding the system stability issues because of an inherent resonance peak which appears in the open-loop transfer function of the inverter control system near the control stability boundary. To avoid passive (resistive) resonance damping solutions, due to their additional power losses, active damping (AD) techniques are often applied with proper control algorithms in order to damp the LCL filter resonance and stabilize the system. Among these techniques, the capacitor current feedback (CCF) AD has attracted considerable attention due to its effective damping performance and simple implementa... [more]
Analysis and Modeling for Short- to Medium-Term Load Forecasting Using a Hybrid Manifold Learning Principal Component Model and Comparison with Classical Statistical Models (SARIMAX, Exponential Smoothing) and Artificial Intelligence Models (ANN, SVM): Th
George P. Papaioannou, Christos Dikaiakos, Anargyros Dramountanis, Panagiotis G. Papaioannou
January 30, 2019 (v1)
Keywords: electricity load, exponential smoothing, forecasting, principal components analysis, seasonal autoregressive integrated moving average with exogenous (SARIMAX)
In this work we propose a new hybrid model, a combination of the manifold learning Principal Components (PC) technique and the traditional multiple regression (PC-regression), for short and medium-term forecasting of daily, aggregated, day-ahead, electricity system-wide load in the Greek Electricity Market for the period 2004⁻2014. PC-regression is shown to effectively capture the intraday, intraweek and annual patterns of load. We compare our model with a number of classical statistical approaches (Holt-Winters exponential smoothing of its generalizations Error-Trend-Seasonal, ETS models, the Seasonal Autoregressive Moving Average with exogenous variables, Seasonal Autoregressive Integrated Moving Average with eXogenous (SARIMAX) model as well as with the more sophisticated artificial intelligence models, Artificial Neural Networks (ANN) and Support Vector Machines (SVM). Using a number of criteria for measuring the quality of the generated in-and out-of-sample forecasts, we have conc... [more]
A New Switching Impulse Generator Based on Transformer Boosting and Insulated Gate Bipolar Transistor Trigger Control
Ming Ren, Chongxing Zhang, Ming Dong, Rixin Ye, Ricardo Albarracín
January 30, 2019 (v1)
Keywords: boosting transformer, impulse generator, impulse waveform parameters, insulated gate bipolar transistor (IGBT), switching impulse (SI)
To make the switching impulse (SI) generator more compact, portable and feasible in field tests, a new approach based on transformer boosting was developed. To address problems such as triggering synchronization and electromagnetic interference involved with the traditional spark gap, an insulated gate bipolar transistor (IGBT) module with drive circuit was employed as the impulse trigger. An optimization design for the component parameters of the primary winding side of the transformer was realized by numerical calculation and error correction. Experiment showed that the waveform parameters of SI and oscillating switching impulse (OSI) voltages generated by the new generator were consistent with the numerical calculation and the error correction. The generator was finally built on a removable high voltage transformer with small size. Thus the volume of the generator is significantly reduced. Experiments showed that the waveform parameters of SI and OSI voltages generated by the new ge... [more]
Comparative Study of Hybrid Models Based on a Series of Optimization Algorithms and Their Application in Energy System Forecasting
Xuejiao Ma, Dandan Liu
January 30, 2019 (v1)
Keywords: comparative study, energy system, forecasting validity degree, optimization algorithms, time series forecasting
Big data mining, analysis, and forecasting play vital roles in modern economic and industrial fields, especially in the energy system. Inaccurate forecasting may cause wastes of scarce energy or electricity shortages. However, forecasting in the energy system has proven to be a challenging task due to various unstable factors, such as high fluctuations, autocorrelation and stochastic volatility. To forecast time series data by using hybrid models is a feasible alternative of conventional single forecasting modelling approaches. This paper develops a group of hybrid models to solve the problems above by eliminating the noise in the original data sequence and optimizing the parameters in a back propagation neural network. One of contributions of this paper is to integrate the existing algorithms and models, which jointly show advances over the present state of the art. The results of comparative studies demonstrate that the hybrid models proposed not only satisfactorily approximate the a... [more]
A Concentrator Photovoltaic System Based on a Combination of Prism-Compound Parabolic Concentrators
Ngoc Hai Vu, Seoyong Shin
January 30, 2019 (v1)
Keywords: compound parabolic concentrator, concentrator photovoltaic, solar cell
We present a cost-effective concentrating photovoltaic system composed of a prism and a compound parabolic concentrator (P-CPC). In this approach, the primary collector consists of a prism, a solid compound parabolic concentrator (CPC), and a slab waveguide. The prism, which is placed on the input aperture of CPC, directs the incoming sunlight beam to be parallel with the main axes of parabolic rims of CPC. Then, the sunlight is reflected at the parabolic rims and concentrated at the focal point of these parabolas. A slab waveguide is coupled at the output aperture of the CPC to collect focused sunlight beams and to guide them to the solar cell. The optical system was modeled and simulated with commercial ray tracing software (LightTools™). Simulation results show that the optical efficiency of a P-CPC can achieve up to 89%. when the concentration ratio of the P-CPC is fixed at 50. We also determine an optimal geometric structure of P-CPC based on simulation. Because of the simplicity... [more]
Non-Vacuum Processed Polymer Composite Antireflection Coating Films for Silicon Solar Cells
Abdullah Uzum, Masashi Kuriyama, Hiroyuki Kanda, Yutaka Kimura, Kenji Tanimoto, Seigo Ito
January 30, 2019 (v1)
Subject: Materials
Keywords: antireflection coating, Czochralski silicon (CZ-Si), low-cost solar cell, nanoparticle, non-vacuum, spin coating, titanium oxide (TiO2), zirconium oxide (ZrO2)
A non-vacuum processing method for preparing polymer-based ZrO₂/TiO₂ multilayer structure antireflection coating (ARC) films for crystalline silicon solar cells by spin coating is introduced. Initially, ZrO₂, TiO₂ and surface deactivated-TiO₂ (SD-TiO₂) based films were examined separately and the effect of photocatalytic properties of TiO₂ film on the reflectivity on silicon surface was investigated. Degradation of the reflectance performance with increasing reflectivity of up to 2% in the ultraviolet region was confirmed. No significant change of the reflectance was observed when utilizing SD-TiO₂ and ZrO₂ films. Average reflectance (between 300 nm⁻1100 nm) of the silicon surface coated with optimized polymer-based ZrO₂ single or ZrO₂/SD-TiO₂ multilayer composite films was decreased down to 6.5% and 5.5%, respectively. Improvement of photocurrent density (Jsc) and conversion efficiency (η) of fabricated silicon solar cells owing to the ZrO₂/SD-TiO₂ multilayer ARC could be confirmed. T... [more]
Effect of Photoanode Design on the Photoelectrochemical Performance of Dye-Sensitized Solar Cells Based on SnO₂ Nanocomposite
I-Ming Hung, Ripon Bhattacharjee
January 30, 2019 (v1)
Keywords: dye-sensitized solar cells (DSSCs), nanocomposite, nanoflower, nanoparticle, photoanode
Li-doped ZnO (LZO) aggregated nanoparticles are used as an insulating layer in SnO₂ nanocomposite (SNC) photoanodes to suppress the recombination process in dye-sensitized solar cells (DSSCs). Various weight percentages of SnO₂ nanoparticles (SNPs) and SnO₂ nanoflowers (SNFs) were used to prepare SNC photoanodes. The photocurrent-voltage characteristics showed that the incorporation of an LZO insulating layer in an SNC photoanode increased the conversion efficiency of DSSCs. This was due to an increase in the surface area, charge injection, and charge collection, and the minimization of the recombination rate of photoanodes. Electrochemical impedance spectroscopy (EIS) results showed lower series resistance, charge injection resistance, and shorter lifetimes for DSSCs based on an SNC photoanode with an LZO insulating layer. The open circuit voltage and fill factor of the DSSCs based on SNC photoanodes with an LZO insulating layer significantly increased. The DSSC based on a SNC photoan... [more]
Theoretical Framework of Organizational Intelligence: A Managerial Approach to Promote Renewable Energy in Rural Economies
Nicolae Istudor, Minodora Ursacescu, Cleopatra Sendroiu, Ioan Radu
January 30, 2019 (v1)
Subject: Energy Policy
Keywords: business strategy, economic intelligence, entropy process, knowledge management, organizational innovation, organizational intelligence, Renewable and Sustainable Energy
The companies involved in the energy sector must reinvent themselves to be innovative and adaptable to contemporary environmental changes. The promotion of renewable energy in rural communities is a great challenge for these companies. They should focus on improving the environment scanning actions and the knowledge management (KM) system and enhancing the collective intelligence to avoid the loss of information, to foster innovation, and to maintain a competitive advantage. To achieve these goals, energy companies require appropriate management tools and practices. The purpose of this study is to propose a theoretical framework of organizational intelligence (OI) supported by a cross-perspective analysis of various aspects: economic intelligence (EI) and KM practices, entropy processes, and organizational enablers. A pilot investigation for testing the framework in the case of Transelectrica S.A. has been elaborated. The findings reveal that the elements of the OI framework are embedd... [more]
A Novel Dynamic Co-Simulation Analysis for Overall Closed Loop Operation Control of a Large Wind Turbine
Ching-Sung Wang, Mao-Hsiung Chiang
January 30, 2019 (v1)
Keywords: co-simulation, dynamic simulation, generator torque control, pitch control, wind turbine, yaw control
A novel dynamic co-simulation methodology of overall wind turbine systems is presented. This methodology combines aerodynamics, mechanism dynamics, control system dynamics, and subsystems dynamics. Aerodynamics and turbine properties were modeled in FAST (Fatigue, Aerodynamic, Structures, and Turbulence), and ADAMS (Automatic Dynamic Analysis of Mechanical Systems) performed the mechanism dynamics; control system dynamics and subsystem dynamics such as generator, pitch control system, and yaw control system were modeled and built in MATLAB/SIMULINK. Thus, this comprehensive integration of methodology expands both the flexibility and controllability of wind turbines. The dynamic variations of blades, rotor dynamic response, and tower vibration can be performed under different inputs of wind profile, and the control strategies can be verified in the different closed loop simulation. Besides, the dynamic simulation results are compared with the measuring results of SCADA (Supervisory Cont... [more]
Estimation of Total Transport CO₂ Emissions Generated by Medium- and Heavy-Duty Vehicles (MHDVs) in a Sector of Korea
Jigu Seo, Junhong Park, Yunjung Oh, Sungwook Park
January 30, 2019 (v1)
Subject: Energy Policy
Keywords: carbon dioxide emission inventory, carbon dioxide emissions, medium and heavy-duty vehicle (MHDV), vehicle simulation
In order to mitigate carbon dioxide (CO₂) emissions, policy action that addresses vehicle emissions is essential. While many previous studies have focused on light-duty vehicles (LDV), little is known about medium- and heavy-duty vehicles (MHDV). This study lays the groundwork for future MHDV investigations in the Republic of Korea by developing an MHDV CO₂ emissions inventory. The bottom-up approach was used to calculate national CO₂ emissions. Simulation methods that calculated the CO₂ emissions of each vehicle and statistical data, such as vehicle miles traveled (VMT) and the number of registered vehicles were used to predict CO₂ emissions. The validity of this simulation model was examined by comparing it with the chassis dynamometer test results. The results of this study showed that the CO₂ emissions of MHDV in 2015 were 24.47 million tons, which was 25.5% of the total road transportation CO₂ emissions, despite only comprising 4.2% of the total vehicles. Trucks emitted 69.6% and... [more]
Design and Implementation of a Test-Bench for Efficiency Measurement of Domestic Induction Heating Appliances
Javier Serrano, Jesús Acero, Rafael Alonso, Claudio Carretero, Ignacio Lope, José Miguel Burdío
January 30, 2019 (v1)
Keywords: efficiency measurement, efficient power transfer, induction heating, measurement station
The operation of a domestic induction cooktop is based on the wireless energy transfer from the inductor to the pot. In such systems, the induction efficiency is defined as the ratio between the power delivered to the pot and the consumed power from the supplying converter. The non-transferred power is dissipated in the inductor, raising its temperature. Most efficiency-measuring methods are based on measuring the effective power (pot) and the total power (converter output). While the converter output power is directly measurable, the measurement of the power dissipation in the pot is usually a cause of inaccuracy. In this work, an alternative method to measure the system’s efficiency is proposed and implemented. The method is based on a pot with a reversible base to which the inductor is attached. In the standard configuration, the inductor is placed below the pot in such a way that the delivered power is used to boil water, and the power losses are dissipated to the air. When the pot... [more]
Lignocellulosic Ethanol Production from the Recovery of Stranded Driftwood Residues
Gianluca Cavalaglio, Mattia Gelosia, Silvia D’Antonio, Andrea Nicolini, Anna Laura Pisello, Marco Barbanera, Franco Cotana
January 30, 2019 (v1)
Subject: Biosystems
Keywords: bioethanol, cellulose hydrolysis, steam explosion, stranded driftwood residues
This paper builds upon a research project funded by the Italian Ministry of Environment, and aims to recover stranded driftwood residues (SDRs), in order to transform a potential pollution and safety issue into valuable bio-resources. In particular, one of the experiments consisted of bioethanol production from lignocellulosic residues. The SDRs were gathered from the Italian coast (Abruzzo Region, Italy) after an intense storm. The biomass recalcitrance, due to its lignocellulosic structure, was reduced by a steam explosion (SE) pretreatment process. Four different pretreatment severity factors (R₀) were tested (LogR₀ 3.65, 4.05, 4.24 and 4.64) in order to evaluate the pretreated material’s accessibility to enzymatic attack and the holocellulose (cellulose plus hemicellulose) recovery. A first enzymatic hydrolysis was performed on the pretreated materials by employing a solid/liquid (S/L) ratio of 1% (w/w) and an enzyme dosage of 30% (w enzyme/w cellulose), in order to estimate the ma... [more]
Dispatching of Wind/Battery Energy Storage Hybrid Systems Using Inner Point Method-Based Model Predictive Control
Deyou Yang, Jiaxin Wen, Ka-wing Chan, Guowei Cai
January 30, 2019 (v1)
Keywords: battery energy storage, combination active output, dispatching curve, wind power
The application of large scale energy storage makes wind farms more dispatchable, which lowers operating risks to the grid from interconnected large scale wind farms. In order to make full use of the flexibility and controllability of energy storage to improve the schedulability of wind farms, this paper presents a rolling and dispatching control strategy with a battery energy storage system (BESS) based on model predictive control (MPC). The proposed control scheme firstly plans expected output, i.e., dispatching order, of a wind/battery energy storage hybrid system based on the predicted output of the wind farm, then calculates the order in the predictive horizon with the receding horizon optimization and the limitations of energy storage such as state of charge and depth of charge/discharge to maintain the combination of active output of the wind farm and the BESS to track dispatching order at the extreme. The paper shows and analyses the effectiveness of the proposed strategy with... [more]
TBM/MTM for HTS-FNSF: An Innovative Testing Strategy to Qualify/Validate Fusion Technologies for U.S. DEMO
Laila El-Guebaly, Arthur Rowcliffe, Jonathan Menard, Thomas Brown
January 30, 2019 (v1)
Subject: Energy Policy
Keywords: fusion nuclear testing facility, high temperature superconducting magnets, materials testing module, spherical tokamak, testing blanket module, testing strategy
The qualification and validation of nuclear technologies are daunting tasks for fusion demonstration (DEMO) and power plants. This is particularly true for advanced designs that involve harsh radiation environment with 14 MeV neutrons and high-temperature operating regimes. This paper outlines the unique qualification and validation processes developed in the U.S., offering the only access to the complete fusion environment, focusing on the most prominent U.S. blanket concept (the dual cooled PbLi (DCLL)) along with testing new generations of structural and functional materials in dedicated test modules. The venue for such activities is the proposed Fusion Nuclear Science Facility (FNSF), which is viewed as an essential element of the U.S. fusion roadmap. A staged blanket testing strategy has been developed to test and enhance the DCLL blanket performance during each phase of FNSF D-T operation. A materials testing module (MTM) is critically important to include in the FNSF as well to... [more]
Methodologies Developed for EcoCity Related Projects: New Borg El Arab, an Egyptian Case Study
Carmen Antuña-Rozado, Justo García-Navarro, Francesco Reda, Pekka Tuominen
January 30, 2019 (v1)
Subject: Energy Policy
Keywords: CO2 emissions, EcoCity, EcoCity methodologies, Egypt, Energy Efficiency, energy survey, feasibility study, roadmap, sustainability scenarios
The aim of the methodologies described here is to propose measures and procedures for developing concepts and technological solutions, which are adapted to the local conditions, to build sustainable communities in developing countries and emerging economies. These methodologies are linked to the EcoCity framework outlined by VTT Technical Research Centre of Finland Ltd. for sustainable community and neighbourhood regeneration and development. The framework is the result of a long experience in numerous EcoCity related projects, mainly Nordic and European in scope, which has been reformulated in recent years to respond to the local needs in the previously mentioned countries. There is also a particular emphasis on close collaboration with local partners and major stakeholders. In order to illustrate how these methodologies can support EcoCity concept development and implementation, results from a case study in Egypt will be discussed. The referred case study relates to the transformatio... [more]
Coordinated Scheme of Under-Frequency Load Shedding with Intelligent Appliances in a Cyber Physical Power System
Qi Wang, Yi Tang, Feng Li, Mengya Li, Yang Li, Ming Ni
January 30, 2019 (v1)
Keywords: cyber physical power system, demand response, intelligent home appliance, under-frequency load shedding
The construction of a cyber physical system in a power grid provides more potential control strategies for the power grid. With the rapid employment of intelligent terminal equipment (e.g., smart meters and intelligent appliances) in the environment of a smart grid, abundant dynamic response information could be introduced to support a secure and stable power system. Combining demand response technology with the traditional under-frequency load shedding (UFLS) scheme, a new UFLS strategy-determining method involving intelligent appliances is put forward to achieve the coordinated control of quick response resources and the traditional control resources. Based on this method, intelligent appliances can be used to meet the regulatory requirements of system operation in advance and prevent significant frequency drop, thereby improving the flexibility and stability of the system. Time-domain simulation verifies the effectiveness of the scheme, which is able to mitigate frequency drop and r... [more]
Techno-Economic Modeling and Analysis of Redox Flow Battery Systems
Jens Noack, Lars Wietschel, Nataliya Roznyatovskaya, Karsten Pinkwart, Jens Tübke
January 30, 2019 (v1)
Keywords: cost, materials, redox flow battery, Technoeconomic Analysis
A techno-economic model was developed to investigate the influence of components on the system costs of redox flow batteries. Sensitivity analyses were carried out based on an example of a 10 kW/120 kWh vanadium redox flow battery system, and the costs of the individual components were analyzed. Particular consideration was given to the influence of the material costs and resistances of bipolar plates and energy storage media as well as voltages and electric currents. Based on the developed model, it was possible to formulate statements about the targeted optimization of a developed non-commercial vanadium redox flow battery system and general aspects for future developments of redox flow batteries.
Perspectives on Near ZEB Renovation Projects for Residential Buildings: The Spanish Case
Faustino Patiño-Cambeiro, Julia Armesto, Faustino Patiño-Barbeito, Guillermo Bastos
January 30, 2019 (v1)
Subject: Energy Policy
Keywords: buildings, cost-optimal, Energy Efficiency, nZEB, renovation
EU regulations are gradually moving towards policies that reduce energy consumption and its environmental impact. To reach this goal, improving energy efficiency in residential buildings is a key action line. The European Parliament adopted the Near Zero-Energy Building (nZEB) as the energy efficiency paradigm through Directive 2010/31/EU, but a common technical and legislative framework for energy renovations is yet to be established. In this paper, the nZEB definition by COHERENO was adopted to evaluate several energy renovation packages in a given building, which is also representative of the Spanish building stock. Global costs are calculated for all of them following EPBD prescriptions. Two economic scenarios are analysed: with entirely private funding and with the current public financial incentives, respectively. The results show the divergence between optimum solutions in terms of costs and of minimum CO₂ footprint and maximum energy saving. Moreover, in the absence of enough i... [more]
Energy Optimization for Train Operation Based on an Improved Ant Colony Optimization Methodology
Youneng Huang, Chen Yang, Shaofeng Gong
January 30, 2019 (v1)
Subject: Optimization
Keywords: ant colony optimization, CBTC, discrete combination, optimization of energy-savings
More and more lines are using the Communication Based Train Control (CBTC) systems in urban rail transit. Trains are operated by tracking a pre-determined target speed curve in the CBTC system, so one of the most effective ways of reducing energy consumption is to fully understand the optimum curves that should prevail under varying operating conditions. Additionally, target speed curves need to be calculated with optimum real-time performance in order to cope with changed interstation planning running time. Therefore, this paper proposes a fast and effective algorithm for optimization, based on a two-stage method to find the optimal curve using a max-min ant colony optimization system, using approximate calculations of a discrete combination optimization model. The first stage unequally discretizes the line based on static gradient and speed limit in low-density and it could conduct a comprehensive search for viable energy saving target speed curves. The second stage unequally discret... [more]
Activity-Aware Energy-Efficient Automation of Smart Buildings
Brian L. Thomas, Diane J. Cook
January 30, 2019 (v1)
Keywords: activity prediction, activity recognition, building automation, cyber-physical systems (CPS), smart cities
This paper introduces the idea of activity-aware cyber-physical systems (CPS). Activity-aware systems allow smart city services to adapt to the needs of individual residents by being sensitive to their daily tasks. The paper first defines activity recognition and activity prediction algorithms that form the foundation of activity-aware CPS and implement a prototype activity-aware building automation system, called CASAS activity aware resource learning (CARL). Evaluation of CARL on real sensor data shows not only an accurate ability to sense and predict activities but an effective means of automation buildings that reduces energy consumption while being sensitive to user activities in the building. Our ideas are demonstrated in the context of a smart home but can be utilized in a variety of smart city settings including smart offices, smart hospitals, and smart communities.
Partial Discharge Measurement under an Oscillating Switching Impulse: A Potential Supplement to the Conventional Insulation Examination in the Field
Ming Ren, Ming Dong, Chongxing Zhang, Jierui Zhou
January 30, 2019 (v1)
Keywords: gas insulated switchgear, impulse voltage, insulation diagnosis, partial discharge, power apparatus, SF6
Partial discharge (PD) detection under oscillating switching impulse (OSI) voltage was performed on three types of insulation defects, including a protrusion on a conductor, a particle on an insulator surface, and a void in an insulator, which are three kinds of the common potential insulation hazards in gas insulated power apparatus. Experiment indicated that the PD sequences under OSI were composed of various combinations of the single pulse, the multiple pulses, and the reverse polarity pulse. The difference between the PD inception voltage (PDIV) and the breakdown voltage (BDV) under OSI voltage was greater than that under alternating current (AC) voltage in some cases, which can provide a more sufficient margin below the BDV for PD diagnosis. The OSI voltage also showed a better performance for exciting PDs with detectable magnitudes from small-scale defects, of which the AC voltage was incapable under our test conditions. The different PD activities with different interfaces unde... [more]
Showing records 133 to 155 of 155. [First] Page: 1 3 4 5 6 7 Last