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ELECTRICAL ENGINEERING (105 journals)                     

Showing 1 - 105 of 105 Journals sorted alphabetically
Actuators     Open Access   (Followers: 4)
Advances in Electrical and Electronic Engineering     Open Access   (Followers: 2)
Advances in Electrical Engineering     Open Access   (Followers: 20)
Advances in Microelectronic Engineering     Open Access   (Followers: 13)
Advances in Signal Processing     Open Access   (Followers: 11)
American Journal of Electrical and Electronic Engineering     Open Access   (Followers: 24)
American Journal of Sensor Technology     Open Access   (Followers: 4)
Archives of Control Sciences     Open Access   (Followers: 3)
Archives of Electrical Engineering     Open Access   (Followers: 12)
Atom Indonesia     Open Access   (Followers: 1)
Case Studies in Mechanical Systems and Signal Processing     Open Access  
Circuits, Systems, and Signal Processing     Hybrid Journal   (Followers: 12)
Computers & Electrical Engineering     Hybrid Journal   (Followers: 9)
Current Trends in Signal Processing     Full-text available via subscription   (Followers: 5)
Edu Elektrika Journal     Open Access  
Electric Power Components and Systems     Hybrid Journal   (Followers: 7)
Electric Power Systems Research     Partially Free   (Followers: 17)
Electrical and Electronic Engineering     Open Access   (Followers: 24)
Electrical and Power Engineering Frontier     Open Access   (Followers: 23)
Electrical Engineering     Hybrid Journal   (Followers: 19)
Electrical Engineering and Automation     Open Access   (Followers: 8)
Electrical Engineering in Japan     Hybrid Journal   (Followers: 8)
Electrical, Control and Communication Engineering     Open Access   (Followers: 13)
Emerging and Selected Topics in Circuits and Systems     Hybrid Journal   (Followers: 8)
EURASIP Journal on Advances in Signal Processing     Open Access   (Followers: 7)
Ferroelectrics     Hybrid Journal   (Followers: 1)
Ferroelectrics Letters Section     Hybrid Journal   (Followers: 1)
Frequenz     Hybrid Journal   (Followers: 1)
Frontiers of Electrical and Electronic Engineering     Hybrid Journal   (Followers: 8)
IEA Electricity Information     Full-text available via subscription   (Followers: 3)
IEEE Access     Open Access   (Followers: 61)
IEEE Electrical Insulation Magazine     Full-text available via subscription   (Followers: 27)
IEEE Signal Processing Magazine     Full-text available via subscription   (Followers: 68)
IEEE Transactions on Control of Network Systems     Hybrid Journal   (Followers: 11)
IEEE Transactions on Dielectrics and Electrical Insulation     Hybrid Journal   (Followers: 13)
IEEE Transactions on Signal and Information Processing over Networks     Full-text available via subscription   (Followers: 8)
IEEJ Transactions on Electrical and Electronic Engineering     Hybrid Journal   (Followers: 14)
IET Control Theory & Applications     Hybrid Journal   (Followers: 23)
IET Electric Power Applications     Hybrid Journal   (Followers: 20)
IET Electrical Systems in Transportation     Hybrid Journal   (Followers: 9)
IETE Journal of Education     Open Access   (Followers: 4)
IJEIS (Indonesian Journal of Electronics and Instrumentation Systems)     Open Access  
Indonesian Journal of Electrical Engineering and Computer Science     Open Access   (Followers: 13)
Ingeniería Electrónica, Automática y Comunicaciones     Open Access  
Integrated Ferroelectrics: An International Journal     Hybrid Journal   (Followers: 1)
International Journal of Advances in Telecommunications, Electrotechnics, Signals and Systems     Open Access   (Followers: 8)
International Journal of Electrical Engineering Education     Hybrid Journal   (Followers: 6)
International Journal of Electrical Power & Energy Systems     Open Access   (Followers: 21)
International Journal of Emerging Electric Power Systems     Hybrid Journal   (Followers: 6)
International Journal of Monitoring and Surveillance Technologies Research     Full-text available via subscription   (Followers: 4)
International Journal of Nano Devices, Sensors and Systems     Open Access   (Followers: 7)
International Journal of Nuclear Security     Open Access   (Followers: 1)
International Journal of Turbomachinery, Propulsion and Power     Open Access   (Followers: 1)
International Journal on Communication     Full-text available via subscription   (Followers: 13)
International Journal on Control System and Instrumentation     Full-text available via subscription   (Followers: 14)
International Journal on Electrical and Power Engineering     Full-text available via subscription   (Followers: 8)
International Journal on Signal and Image Processing     Full-text available via subscription   (Followers: 4)
International Transaction of Electrical and Computer Engineers System     Open Access   (Followers: 2)
International Transactions on Electrical Energy Systems     Hybrid Journal   (Followers: 8)
Izvestiya Vysshikh Uchebnykh Zavedenii. Materialy Elektronnoi Tekhniki : Materials of Electronics Engineering     Full-text available via subscription  
J3eA     Open Access   (Followers: 2)
Journal of Control, Automation and Electrical Systems     Hybrid Journal   (Followers: 10)
Journal of Electrical and Computer Engineering     Open Access   (Followers: 9)
Journal of Electrical and Computer Engineering Innovations     Open Access   (Followers: 4)
Journal of Electrical and Electronics Engineering Research     Open Access   (Followers: 19)
Journal of Electrical Bioimpedance     Open Access   (Followers: 2)
Journal of Electrical Engineering     Open Access   (Followers: 22)
Journal of Electrical Engineering & Electronic Technology     Hybrid Journal   (Followers: 7)
Journal of Electrical Systems and Information Technology     Open Access   (Followers: 6)
Journal of Field Robotics     Hybrid Journal   (Followers: 2)
Journal of International Council on Electrical Engineering     Open Access  
Journal of Micro-Bio Robotics     Hybrid Journal  
Journal of Microwaves, Optoelectronics and Electromagnetic Applications     Open Access   (Followers: 9)
Journal of Power Technologies     Open Access   (Followers: 6)
Journal of the Society for Information Display     Hybrid Journal  
Journal of World's Electrical Engineering and Technology     Open Access   (Followers: 2)
Journal of Zhejiang University SCIENCE C     Hybrid Journal  
Jurnal Elkomika     Open Access  
Jurnal Ilmiah Mahasiswa SPEKTRUM     Open Access  
Jurnal Nasional Teknik Elektro     Open Access   (Followers: 4)
Jurnal Rekayasa Elektrika     Open Access  
Majalah Ilmiah Teknologi Elektro : Journal of Electrical Technology     Open Access   (Followers: 2)
Majlesi Journal of Electrical Engineering     Open Access   (Followers: 1)
Micro and Nano Systems Letters     Open Access   (Followers: 5)
Nanotechnology Development     Open Access   (Followers: 20)
Oil, Gas, Coal and Electricity - Quarterly Statistics - Electricite, charbon, gaz et petrole - Statistiques trimestrielles     Full-text available via subscription   (Followers: 9)
Photovoltaics, IEEE Journal of     Hybrid Journal   (Followers: 14)
Quantum Beam Science     Open Access  
Recent Patents on Electrical & Electronic Engineering     Full-text available via subscription   (Followers: 9)
Recent Patents on Telecommunications     Full-text available via subscription   (Followers: 2)
Research & Reviews : Journal of Embedded System & Applications     Full-text available via subscription   (Followers: 5)
Russian Electrical Engineering     Hybrid Journal   (Followers: 4)
SID Symposium Digest of Technical Papers     Hybrid Journal  
Simetris : Jurnal Teknik Mesin, Elektro dan Ilmu Komputer     Open Access  
Sustainable Energy, Grids and Networks     Hybrid Journal   (Followers: 4)
Sustainable Energy, IEEE Transactions on     Hybrid Journal   (Followers: 16)
Synthesis Lectures on Electrical Engineering     Full-text available via subscription   (Followers: 2)
System analysis and applied information science     Open Access  
Telematique     Open Access  
Transactions on Environment and Electrical Engineering     Open Access  
Trends in Electrical Engineering     Full-text available via subscription   (Followers: 4)
Tri Dasa Mega : Jurnal Teknologi Reaktor Nuklir     Open Access  
Universal Journal of Electrical and Electronic Engineering     Open Access   (Followers: 6)
Wireless Engineering and Technology     Open Access   (Followers: 4)
Електротехніка і Електромеханіка     Open Access  


Journal Cover Sustainable Energy, IEEE Transactions on
  [SJR: 3.646]   [H-I: 45]   [16 followers]  Follow
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 1949-3029
   Published by IEEE Homepage  [191 journals]
  • IEEE Transactions on Sustainable Energy
    • Abstract: Presents a listing of the editorial board, board of governors, current staff, committee members, and/or society editors for this issue of the publication.
      PubDate: Oct. 2017
      Issue No: Vol. 8, No. 4 (2017)
  • IEEE Transactions on Sustainable Energy
    • Abstract: Provides a listing of current committee members and society officers.
      PubDate: Oct. 2017
      Issue No: Vol. 8, No. 4 (2017)
  • Information for Authors
    • Abstract: These instructions give guidelines for preparing papers for this publication. Presents information for authors publishing in this journal.
      PubDate: Oct. 2017
      Issue No: Vol. 8, No. 4 (2017)
  • Co-Optimization Scheme for Distributed Energy Resource Planning in
           Community Microgrids
    • Authors: Chen Yuan;Mahesh S. Illindala;Amrit S. Khalsa;
      Pages: 1351 - 1360
      Abstract: Microgrids with distributed energy resources are being favored in various communities to lower the dependence on utility-supplied energy and cut the CO2 emissions from coal-based power plants. This paper presents a co-optimization strategy for distributed energy resource planning to minimize total annualized cost at the maximal fuel savings. Furthermore, the proposed scheme aids the community microgrids in satisfying the requirements of U.S. Department of Energy (DOE) and state renewable energy mandates. The method of Lagrange multipliers is employed to maximize fuel savings by satisfying Karush-Kuhn-Tucker conditions. With the Fourier transform and particle swarm optimization, the right mix of distributed energy resources is determined to decrease the annualized cost. A case study to test the proposed scheme for a community microgrid is presented. To validate its effectiveness, an economic justification of the solution and its comparison with HOMER Pro are also illustrated.
      PubDate: Oct. 2017
      Issue No: Vol. 8, No. 4 (2017)
  • Decentralized Solution for Combined Heat and Power Dispatch Through
           Benders Decomposition
    • Authors: Chenhui Lin;Wenchuan Wu;Boming Zhang;Yong Sun;
      Pages: 1361 - 1372
      Abstract: The operational flexibility of electric power systems (EPS) is restricted by combined heat and power (CHP) units that act to maintain sufficient heating supply. By exploiting the pipeline heat storage property in central heating systems (CHS), combined heat and power dispatch (CHPD) can significantly increase the operational flexibility and reduce wind power curtailment. In this paper, pipeline heat storage is modeled in the CHPD model under the constant mass flow heating dispatch mode, and the CHPD model can be formulized as a quadratic programming problem. Since the EPS and CHS are independently operated by the EPS and CHS operators, a decentralized solution to the CHPD model is proposed. During each iteration of the decentralized procedure, an optimal cut or a feasible cut is generated by the CHS operator and sent to the EPS operator. A robust model considering the wind power uncertainty is also studied with the proposed decentralized solution. This decentralized solution has a high efficiency and a light communication burden. Numerical tests on practical systems demonstrate the feasibility of the proposed decentralized method and the economic benefits brought by reducing wind curtailment.
      PubDate: Oct. 2017
      Issue No: Vol. 8, No. 4 (2017)
  • Harmonic Assessment for Wind Parks Based on Sensitivity Analysis
    • Authors: Zifa Liu;Jun Rong;Guankun Zhao;Ya Luo;
      Pages: 1373 - 1382
      Abstract: The wind power generation is currently a promising renewable energy technology. A critical feature of wind park is the existence of large distributed capacitance because of the cable laying and offshore cable transmission. This phenomenon is likely to cause harmonic resonance issues, and may threat the safety operation of wind parks. Meanwhile, the operation condition of wind turbines and the topology of wind parks affect the system structure and parameters, then affect the system harmonic resonance. Therefore, a dynamic harmonic model of the most widely used doubly fed induction generator was established to study the behaviors of harmonic resonance. At the same time, other primary electrical components in wind parks are also considered, such as power cables and transformers. In this paper, the harmonic resonance of the wind park is investigated based on the measured data and the modal sensitivity analysis. With considering the impact of various parameters on the frequency and amplitude of resonance, the sensitivity indices for these parameters are also calculated. Finally, the frequency shift method is introduced to solve resonance issue.
      PubDate: Oct. 2017
      Issue No: Vol. 8, No. 4 (2017)
  • A Statistical Model for Hourly Large-Scale Wind and Photovoltaic
           Generation in New Locations
    • Authors: Jussi Ekström;Matti Koivisto;Ilkka Mellin;Robert John Millar;Matti Lehtonen;
      Pages: 1383 - 1393
      Abstract: The analysis of large-scale wind and photovoltaic (PV) energy generation is of vital importance in power systems, where their penetration is high. This paper presents a modular methodology to assess the power generation and volatility of a system consisting of both PV plants (PVPs) and wind power plants (WPPs) in new locations. The methodology is based on statistical modeling of PV and WPP locations with a vector autoregressive model, which takes into account both the temporal correlations in individual plants and the spatial correlations between the plants. The spatial correlations are linked through distances between the locations, which allow the methodology to be used to assess scenarios with PVPs and WPPs in multiple locations without actual measurement data. The methodology can be applied by the transmission and distribution system operators when analyzing the effects and feasibility of new PVPs and WPPs in system planning. The model is verified against hourly measured wind speed and solar irradiance data from Finland. A case study assessing the impact of the geographical distribution of the PVPs and WPPs on aggregate power generation and its variability is presented.
      PubDate: Oct. 2017
      Issue No: Vol. 8, No. 4 (2017)
  • Impact of Public Aggregate Wind Forecasts on Electricity Market Outcomes
    • Authors: Lazaros Exizidis;Jalal Kazempour;Pierre Pinson;Zacharie De Grève;François Vallée;
      Pages: 1394 - 1405
      Abstract: Following a call to foster a transparent and more competitive market, member states of the European transmission system operator are required to publish, among other information, aggregate wind power forecasts. The publication of the latter information is expected to benefit market participants by offering better knowledge of the market operation, leading subsequently to a more competitive energy market. Driven by the above regulation, we consider an equilibrium study to address how public information of aggregate wind power forecasts can potentially affect market results, social welfare, as well as the profits of participating power producers. We investigate, therefore, a joint day-ahead energy and reserve auction, where producers offer their conventional power strategically based on a complementarity approach and their wind power at generation cost based on a forecast. In parallel, an iterative game-theoretic approach (diagonalization) is incorporated in order to investigate the existence of an equilibrium for various values of aggregate forecast. As anticipated, variations in public forecasts will affect market results and, more precisely, underforecasts can mislead power producers to make decisions that favor social welfare, while overforecasts will cause the opposite effect. Furthermore, energy and reserve market prices can also be affected by deviations in aggregate wind forecasts altering, inevitably, the profits of all power producers.
      PubDate: Oct. 2017
      Issue No: Vol. 8, No. 4 (2017)
  • Analysis of Energy Curtailment and Capacity Overinstallation to Maximize
           Wind Turbine Profit Considering Electricity Price–Wind Correlation
    • Authors: Peiyuan Chen;Torbjörn Thiringer;
      Pages: 1406 - 1414
      Abstract: This paper proposes a strategy of using wind energy curtailment and capacity overinstallation to increase the profit of wind turbine (WT) installations in a local grid, accounting for the correlation between the local wind power production and system electricity price. It is demonstrated that the market value of a local wind power production in Denmark would be overestimated by 11% if the average electricity price is used without considering the price-wind correlation. A first-order relation is developed to quantify the correlation between the electricity price and local wind power production to evaluate the market value and the expected revenue of the wind power. Furthermore, in the analyzed cases of a local WT installation, compared to the case with no curtailment, the profits are increased by up to 46% through 29% of energy curtailment and 113% of capacity overinstallation, when the slope of the price-wind relation is 100 €/MWh. It is also verified that the approximated analytical solutions give accurate results of the optimal curtailment level.
      PubDate: Oct. 2017
      Issue No: Vol. 8, No. 4 (2017)
  • Multi-Objective Bilevel Coordinated Planning of Distributed Generation and
           Distribution Network Frame Based on Multiscenario Technique Considering
           Timing Characteristics
    • Authors: Yajing Gao;Xiaobo Hu;Wenhai Yang;Haifeng Liang;Peng Li;
      Pages: 1415 - 1429
      Abstract: This paper presents a novel approach to planning distributed generation (DG) and distribution network frames based on a multiscenario technique. In view of the uncertainties of the load and intermittence of the DG output, the annual timing characteristics are analyzed, and the daily load and output of DG are divided into several typical situations according to respective influence factors. In the target planning year, the uncertain units are simulated using the typical daily forecast values, then the probability models are established considering the forecast errors; finally, multiple scenarios are achieved through Latin hypercube sampling and sample reduction. In view of the interaction of DG and distribution network frames, a bilevel coordinated planning model is proposed, in which the upper level planning is aimed to achieve the integrated optimal decision and the goal of the lower level planning is to comprehensively consider the benefits of DG. Finally, hybrid chaos binary particle swarm optimization based on Pareto set theory and niche sharing is applied to make a nested solving of the model, and the superiority and effectiveness of the proposed model are verified in the IEEE 33-node and 69-node distribution systems as the test cases.
      PubDate: Oct. 2017
      Issue No: Vol. 8, No. 4 (2017)
  • Coordinated Control Method of Voltage and Reactive Power for Active
           Distribution Networks Based on Soft Open Point
    • Authors: Peng Li;Haoran Ji;Chengshan Wang;Jinli Zhao;Guanyu Song;Fei Ding;Jianzhong Wu;
      Pages: 1430 - 1442
      Abstract: The increasing penetration of distributed generators (DGs) exacerbates the risk of voltage violations in active distribution networks (ADNs). The conventional voltage regulation devices limited by the physical constraints are difficult to meet the requirement of real-time voltage and VAR control (VVC) with high precision when DGs fluctuate frequently. However, soft open point (SOP), a flexible power electronic device, can be used as the continuous reactive power source to realize the fast voltage regulation. Considering the cooperation of SOP and multiple regulation devices, this paper proposes a coordinated VVC method based on SOP for ADNs. First, a time-series model of coordinated VVC is developed to minimize operation costs and eliminate voltage violations of ADNs. Then, by applying the linearization and conic relaxation, the original nonconvex mixed-integer nonlinear optimization model is converted into a mixed-integer second-order cone programming model which can be efficiently solved to meet the requirement of voltage regulation rapidity. Case studies are carried out on the IEEE 33-node system and IEEE 123-node system to illustrate the effectiveness of the proposed method.
      PubDate: Oct. 2017
      Issue No: Vol. 8, No. 4 (2017)
  • A Decentralized Control Strategy for Autonomous Transient Power Sharing
           and State-of-Charge Recovery in Hybrid Energy Storage Systems
    • Authors: Qianwen Xu;Jianfang Xiao;Peng Wang;Xuewei Pan;Changyun Wen;
      Pages: 1443 - 1452
      Abstract: This paper proposes a decentralized power management strategy for hybrid energy storage systems to achieve transient power sharing and state-of-charge (SoC) recovery simultaneously. A virtual capacitance droop control strategy with an autonomous SoC recovery loop is proposed for energy storage (ES) with fast dynamic response, and the conventional virtual resistance droop control method is employed to regulate ES with slow dynamic response. The hybrid battery/supercapacitor (SC) system is taken as an application example. With the proposed method, load power is autonomously split into high-frequency and low-frequency parts to be compensated by SC and battery. Meanwhile, SC SoC is automatically recovered and this enables continuous operation of the SC as a power buffer without mode change or performance tradeoff. A design guideline is developed to ensure desired transient power sharing dynamics and SoC recovery with negligible interactions. Both simulations and experiments are conducted to validate the effectiveness of the proposed strategy and analytical results.
      PubDate: Oct. 2017
      Issue No: Vol. 8, No. 4 (2017)
  • Current-Based Gear Fault Detection for Wind Turbine Gearboxes
    • Authors: Dingguo Lu;Wei Qiao;Xiang Gong;
      Pages: 1453 - 1462
      Abstract: Gearbox faults contribute to a significant portion of the faults and downtime of wind turbines. Gearbox fault detection using the electrical signals acquired from generator terminals has advantages over traditional vibration-based methods in terms of cost, hardware complexity, implementation, and reliability. This paper analyzes the principle of using the nonstationary stator current signals of a generator for the fault detection of a multistage gearbox connected to the generator in varying-speed conditions. Based on the analysis, the characteristic frequencies of various gearbox faults in the frequency spectra of the generator stator currents are identified. A method is then proposed for the fault detection of the gearbox using the current signals. The method consists of an adaptive signal resampling algorithm to convert the nonstationary characteristic frequencies of gearbox faults in the current signals to constant values when the gearbox operates in varying-speed conditions, a statistical analysis algorithm to extract the fault features from the frequency spectra of the resampled stator current signals, and two fault detectors based on the extracted fault features. Experimental results on a two-stage gearbox connected to an electric generator are given to show the effectiveness of the proposed analysis and method for detection of a variety of gear faults in the gearbox.
      PubDate: Oct. 2017
      Issue No: Vol. 8, No. 4 (2017)
  • Wind Turbine Structural Modeling Consideration for Dynamic Studies of DFIG
           Based System
    • Authors: Ganesh P. Prajapat;Nilanjan Senroy;Indra Narayan Kar;
      Pages: 1463 - 1472
      Abstract: This paper presents the dynamic analysis of a grid connected Doubly Fed Induction Generator based wind turbine generator system with the detailed mechanical structural modelling of the wind turbine. The Euler-Lagrangian approach has been used for the structural dynamics of the wind turbine. The driving input mechanical power to the wind turbine has been modelled by the Blade Element Momentum (BEM) method and same has been used to calculate the tangential force on the blades responsible for the edgewise vibration of it. A polynomial regression model and feed-forward back-propagation neural network have been used to replace the BEM algorithm for modal analysis and time-domain simulation, respectively. The different modes of the entire system at different operating points and system parameters have been found and the grid-structure interaction is analyzed. The results offer a deep understanding of the combined electromechanical, aerodynamic, and mechanical structural dynamics of the system and may further be used to design various control schemes. The structural and aerodynamic data from the NREL 5-MW three-bladed Horizontal Axis Wind Turbine were used for the simulation. The model has been validated by NREL's simulation tool, FAST v7.
      PubDate: Oct. 2017
      Issue No: Vol. 8, No. 4 (2017)
  • SSR Mitigation With a New Control of PV Solar Farm as STATCOM (PV-STATCOM)
    • Authors: Rajiv K. Varma;Reza Salehi;
      Pages: 1473 - 1483
      Abstract: This paper presents a novel control of a large-scale PV solar farm as STATCOM, termed PV-STATCOM, for alleviation of subsynchronous resonance (SSR) in a steam turbine driven synchronous generator connected to a series compensated transmission line. During nighttime, the PV solar farm can operate as a STATCOM with its entire inverter capacity for SSR mitigation. During daytime, if a system fault triggers SSR, the solar farm autonomously discontinues its normal active power generation and releases its entire inverter capacity to operate as PV-STATCOM for SSR prevention. Once the subsynchronous resonances are damped, the solar farm returns to its normal real power production. Electromagnetic transients studies using EMTDC/PSCAD are performed to demonstrate that a solar farm connected at the terminals of synchronous generator in the IEEE First SSR Benchmark system can damp all the four torsional modes at all the four critical levels of series compensation, and return to normal PV power production in less than half a minute. This proposed PV-STATCOM technology can either obviate or reduce the need of an expensive flexible ac transmission system device to accomplish the same objective. Furthermore, this technology is more than an order of magnitude cheaper than a conventional static var compensators or STATCOM of similar size.
      PubDate: Oct. 2017
      Issue No: Vol. 8, No. 4 (2017)
  • Artificial Neural Network for Control and Grid Integration of Residential
           Solar Photovoltaic Systems
    • Authors: Yang Sun;Shuhui Li;Bo Lin;Xingang Fu;Malek Ramezani;Ishan Jaithwa;
      Pages: 1484 - 1495
      Abstract: Residential solar photovoltaic (PV) energy is becoming an increasingly important part of the world's renewable energy. A residential solar PV array is usually connected to the distribution grid through a single-phase inverter. Control of the single-phase PV system should maximize the power output from the PV array while ensuring overall system performance, safety, reliability, and controllability for interface with the electricity grid. This paper has two main objectives. The first objective is to develop an artificial neural network (ANN) vector control strategy for an LCL-filter based single-phase solar inverter. The ANN controller is trained to implement optimal control, based on approximate dynamic programming. The second objective is to evaluate the performance of the ANN-based solar PV system by simulating the PV system behavior for grid integration and maximum power extraction from solar PV array in a realistic residential PV application and building an experimental solar PV system for hardware validation. The results demonstrate that a residential PV system using the ANN control outperforms the PV system using the conventional standard vector control method and proportional resonant control method in both simulation and hardware implementation. This is also true in the presence of noise, disturbance, distortion, and nonideal conditions.
      PubDate: Oct. 2017
      Issue No: Vol. 8, No. 4 (2017)
  • A New Asymmetric Multilevel Inverter Topology Suitable for Solar PV
           Applications With Varying Irradiance
    • Authors: Sumit K. Chattopadhyay;Chandan Chakraborty;
      Pages: 1496 - 1506
      Abstract: A new asymmetrical multilevel inverter topology is reported that is capable to operate satisfactorily with wide variation in dc-link voltage, while feeding power to the ac grid. A topological building block is first introduced that has one full-bridge inverter connected in series with a level doubling network. Following this, the interconnection of such building blocks is attempted to increase the number of levels at the output voltage waveform. The investigation reveals that for a three-phase system, a converter configuration with two such building blocks is capable to generate a nominal asymmetry of 14:7:2:1 using only four voltage sources. In solar Photovoltaic (PV) applications, one main source may be fed by PV array and the other three auxiliary sources may be fed through separate dc/dc converters, each having power rating of 3.2% of the peak power rating of PV arrays. The proposed converter can generate 3097 space vectors. Asymmetrical hexagonal decomposition is modified (to ensure satisfactory operation of LDN and to eliminate any dc component in the phase voltage waveform) to control such converter. The converter is extensively simulated in MATLAB/Simulink. A solar PV system of 9.4 kWp available in the laboratory is used to feed power to the grid at different irradiance. Simulation results match well with the prototype experiments confirming the usefulness of the proposed topological alternative for solar PV applications.
      PubDate: Oct. 2017
      Issue No: Vol. 8, No. 4 (2017)
  • A Sustainable Energy Management System for Isolated Microgrids
    • Authors: Bharatkumar V. Solanki;Kankar Bhattacharya;Claudio A. Cañizares;
      Pages: 1507 - 1517
      Abstract: In this paper, the equivalent CO2 emission models for fossil-fuel-based distributed generator units are developed considering their individual emission characteristic and fuel consumption. These models are then integrated within a microgrid energy management system (EMS) model. Constant energy, demand shifting load models are further integrated in the EMS to examine the possible impact of demand response (DR) on the total system emissions and economics of a microgrid. Thus, the impacts of including the developed emission models on the operation of an isolated microgrid, equivalent CO2 emissions, and costs are examined considering five different operating strategies. The proposed operating strategies are validated on a modified CIGRE medium voltage benchmark system. The results obtained highlight the effectiveness of the proposed EMS and also demonstrate the impact of DR on emissions and costs.
      PubDate: Oct. 2017
      Issue No: Vol. 8, No. 4 (2017)
  • Multiresonant Feedback Control of a Three-Degree-of-Freedom Wave Energy
    • Authors: Ossama Abdelkhalik;Shangyan Zou;Rush D. Robinett;Giorgio Bacelli;David G. Wilson;Ryan Coe;Umesh Korde;
      Pages: 1518 - 1527
      Abstract: For a three-degree-of-freedom wave energy converter (heave, pitch, and surge), the equations of motion could be coupled depending on the buoy shape. This paper presents a multiresonant feedback control, in a general framework, for this type of a wave energy converter that is modeled by linear time invariant dynamic systems. The proposed control strategy finds the optimal control in the sense that it computes the control based on the complex conjugate criteria. This control strategy is relatively easy to implement since it is a feedback control in the time domain that requires only measurements of the buoy motion. Numerical tests are presented for two different buoy shapes: a sphere and a cylinder. Regular, Bretschnieder, and Ochi-Hubble waves are tested. Simulation results show that the proposed controller harvests energy in the pitch-surge-heave modes that is about three times the energy that can be harvested using a heave-only device. This multiresonant control can also be used to shift the energy harvesting between the coupled modes, which can be exploited to eliminate one of the actuators while maintaining about the same level of energy harvesting.
      PubDate: Oct. 2017
      Issue No: Vol. 8, No. 4 (2017)
  • Ordinal Optimization Technique for Three-Phase Distribution Network State
           Estimation Including Discrete Variables
    • Authors: Sara Nanchian;Ankur Majumdar;Bikash Chandra Pal;
      Pages: 1528 - 1535
      Abstract: This paper has discussed transformer tap position estimation with continuous and discrete variables in the context of three-phase distribution state estimation (SE). Ordinal optimization (OO) technique has been applied to estimate the transformer tap position for the first time in an unbalanced three-phase distribution network model. The results on 129 bus system model have demonstrated that the OO method can generate a reliable estimate for transformer exact tap position with discrete variables in distribution system SE and also in short period of time. In this paper, the node voltages and power losses are calculated for 129 bus network. It is also demonstrated that OO is much faster than other accurate methods such hybrid particle swarm optimization. The losses obtained with OO are much accurate. In view of this, OO performs better than weighted least square as it provides higher accuracy of the loss calculation. In a distribution network where about 5-6% of electricity generated is lost, accurate estimation of this loss has significant technical and commercial value. The authors believe the technique proposed will help realize those benefits.
      PubDate: Oct. 2017
      Issue No: Vol. 8, No. 4 (2017)
  • Day-Ahead Prediction of Bihourly Solar Radiance With a Markov Switch
    • Authors: Yu Jiang;Huan Long;Zijun Zhang;Zhe Song;
      Pages: 1536 - 1547
      Abstract: A Bayesian inference based Markov regime switching model is introduced to predict the intraday solar radiance. The proposed model utilizes a regime switching process to describe the evolution of the solar radiance time series. The optimal number of regimes and regime-specific parameters are determined by the Bayesian inference. The Markov regime switching model provides both the point and interval prediction of solar radiance based on the posterior distribution derived from historical data by the Bayesian inference. Four solar radiance forecasting models, the persistence model, the autoregressive (AR) model, the Gaussian process regression (GPR) model, and the neural network (NN) model, are considered as baseline models for validating the Markov switching model. The comparative analysis based on numerical experiment results demonstrates that in general the Markov regime switching model performs better than compared models in the day-ahead point and interval prediction of the solar radiance.
      PubDate: Oct. 2017
      Issue No: Vol. 8, No. 4 (2017)
  • Stochastic Optimal Scheduling Based on Scenario Analysis for Wind Farms
    • Authors: Jian Xu;Xiankun Yi;Yuanzhang Sun;Tiankai Lan;Hui Sun;
      Pages: 1548 - 1559
      Abstract: In the scheduling of wind farms, the fluctuation of system's power demand is required to track within a certain time period. It benefits to reasonably arrange division of wind turbines and distribution of active power output. This paper proposes a stochastic optimal scheduling method based on scenario analysis for wind farms. While tracking the power demand on the system side, the uncertainty of wind speed and the effect of wake flow in the wind farm are also considered in the model in order to minimize the operating cost. The method of scenario analysis can determine uncertain variables, and the nonuniform segmentation piecewise linearization method is used to linearize the model. The mixed-integer linear programming method is used to figure out the optimal scheduling strategy for the wind farm, thus, greatly increasing the economical operation of the wind farm. This proposed method is proved to be effective on an actual wind farm in East Inner Mongolia of China.
      PubDate: Oct. 2017
      Issue No: Vol. 8, No. 4 (2017)
  • Volt-VAr Control and Energy Storage Device Operation to Improve the
           Electric Vehicle Charging Coordination in Unbalanced Distribution Networks
    • Authors: Carlos Sabillon-Antunez;Ozy D. Melgar-Dominguez;John F. Franco;Marina Lavorato;Marcos J. Rider;
      Pages: 1560 - 1570
      Abstract: In this paper, a new approach is presented to solve the electric vehicle charging coordination (EVCC) problem considering Volt-VAr control, energy storage device (ESD) operation and dispatchable distributed generation (DG) available in three-phase unbalanced electrical distribution networks (EDNs). Dynamic scheduling for the EVCC is proposed through a step-by-step methodology, which solves a mixed integer linear programming (MILP) problem for the whole time period. The objective is to minimize the total cost of energy purchased from the substation and DG units, the cost of energy curtailment on electric vehicles, the cost of energy injected from the ESDs, and the cost of energy curtailment on the ESDs. The Volt-VAr control considers the management of on-load tap changers, voltage regulators, and switchable capacitors installed along the grid. Furthermore, the formulation takes into account the voltage dependence of the loads, while the steady-state operation of the unbalanced distribution systems is modeled using linear constraints. The proposed model was tested in a 178-node three-phase unbalanced EDN considering a one-day time period.
      PubDate: Oct. 2017
      Issue No: Vol. 8, No. 4 (2017)
  • Improving Renewable Energy Forecasting With a Grid of Numerical Weather
    • Authors: José R. Andrade;Ricardo J. Bessa;
      Pages: 1571 - 1580
      Abstract: In the last two decades, renewable energy forecasting progressed toward the development of advanced physical and statistical algorithms aiming at improving point and probabilistic forecast skill. This paper describes a forecasting framework to explore information from a grid of numerical weather predictions (NWP) applied to both wind and solar energy. The methodology combines the gradient boosting trees algorithm with feature engineering techniques that extract the maximum information from the NWP grid. Compared to a model that only considers one NWP point for a specific location, the results show an average point forecast improvement (in terms of mean absolute error) of 16.09% and 12.85% for solar and wind power, respectively. The probabilistic forecast improvement, in terms of continuous ranked probabilistic score, was 13.11% and 12.06%, respectively.
      PubDate: Oct. 2017
      Issue No: Vol. 8, No. 4 (2017)
  • PLL-Induced Modal Resonance of Grid-Connected PMSGs With the Power System
           Electromechanical Oscillation Modes
    • Authors: Wenjuan Du;Xiao Chen;Haifeng Wang;
      Pages: 1581 - 1591
      Abstract: This study investigates the impact of a grid-connected permanent magnet synchronous generator (PMSG) for wind power generation on the power system electromechanical oscillation modes (EOMs) caused by a phase-locked loop (PLL). A closed-loop interconnected model of a power system with the PMSG is established, where the PLL and rest of the power system are modeled as two separate open-loop interconnected subsystems. Analysis based on the established model indicates that, when an open-loop PLL oscillation mode (POM) is close to an open-loop EOM of concern on the complex plane, the dynamic interactions between the PMSG and the power system may become strong. It is very likely that the modal resonance due to the closeness of the open-loop POM and EOM may degrade the small-signal stability of the power system. In this paper, case studies of an example power system with PMSGs are presented. It is demonstrated that open-loop modal resonance occurs when power system operating conditions change and the PLL parameters are tuned. Strong dynamic interactions between the PMSGs and power system are caused by the open-loop modal resonance, resulting in considerable damping degradation of the low-frequency electromechanical oscillations.
      PubDate: Oct. 2017
      Issue No: Vol. 8, No. 4 (2017)
  • A Markov-Chain-Based Availability Model of Offshore Wind Turbine
           Considering Accessibility Problems
    • Authors: Ling-Ling Huang;Yang Fu;Yang Mi;Jia-Lin Cao;Peng Wang;
      Pages: 1592 - 1600
      Abstract: Availability of wind turbine (WT) is an essential parameter both for wind project feasibility analysis and operation and maintenance optimizations, but in offshore wind farms, it is greatly affected by accessibility which has been seldom considered in traditional reliability evaluations. This paper presents a Markov-chain-based availability assessing model of offshore WT considering accessibility problems. Based on the procedure analysis of corrective maintenance offshore, the contribution of poor accessibility to availability is summarized into two independent aspects: stochastic offshore weather and inadequate maintenance resources. A three-state model of offshore WT is established. A Poisson-process-based algorithm is presented to calculate a transition rate of the three-state model. A three-integer field representing a wind farm with NWT WTs is defined for the Markov chain. Mean availability of WT is obtained by solving a Markov transition matrix. The results of case study show that the proposed model provides an effective approach for the availability assessment of WT in a multi-turbine wind farm influenced by stochastic offshore weather and different logistic policies.
      PubDate: Oct. 2017
      Issue No: Vol. 8, No. 4 (2017)
  • Estimation of Solar Irradiance on Solar Fields: An Analytical Approach and
           Experimental Results
    • Authors: Samer Yassin Alsadi;Yasser Fathi Nassar;
      Pages: 1601 - 1608
      Abstract: An extensive experiment has been designed and conducted to measure the magnitude of solar irradiance falling upon a photovoltaic solar field. The experimental results show that the second and succeeding rows received less solar irradiance than the first row. In addition, there was a degradation of the solar irradiance along a single row directing toward the center of that row. Nowadays, all available models are addressing the solar radiation incident on a single surface. However, the nature of multirows solar fields is different from that of a single surface, which indicates that these models are not suitable for solar irradiance calculation, and there is no work regarding this topic. The aim of this study is to modify a model so the design parameters are included in one model that estimates the solar irradiance on solar fields. The effect of the design parameters was demonstrated. In order to state the validity of the proposed model, a comparison between models that were used in literature and the proposed model along with the experimental results has been provided. The impact of solar degradation on the electrical characteristics has been briefly discussed.
      PubDate: Oct. 2017
      Issue No: Vol. 8, No. 4 (2017)
  • Control Techniques With System Efficiency Comparison for Microwind
    • Authors: Danilo Xavier Llano;Richard A. McMahon;
      Pages: 1609 - 1617
      Abstract: This paper presents the implementation of a sensorless speed controller and active rectification in a microwind turbine intended for battery charging. The controller was tested in a wind turbine emulator test rig using real wind data available from British bases in Antarctica. The control algorithm was successfully tested up to 14 m/s wind speed. Beyond this point, the electrical unbalance in the turbine generator compromised the stability and performance of the system. Also, a system efficiency comparison of different control algorithms is given to demonstrate the advantages of using active rectification instead of passive diode rectifiers in microwind turbines. This comparison was done between the sensorless control plus active rectifier, a dc-dc converter regulator, and the direct connection between the turbine and battery by means of a diode rectifier. The turbine with an active rectifier and sensorless control achieved the highest power coefficient over the range of wind speeds showing that this technique is an attractive and relatively low-cost solution for maintaining good performance of microwind turbines at low and moderate wind speeds.
      PubDate: Oct. 2017
      Issue No: Vol. 8, No. 4 (2017)
  • Control of a Realistic Wave Energy Converter Model Using Least-Squares
           Policy Iteration
    • Authors: Enrico Anderlini;David I. M. Forehand;Elva Bannon;Mohammad Abusara;
      Pages: 1618 - 1628
      Abstract: An algorithm has been developed for the resistive control of a nonlinear model of a wave energy converter using least-squares policy iteration, which incorporates function approximation, with tabular and radial basis functions being used as features. With this method, the controller learns the optimal power take-off damping coefficient in each sea state for the maximization of the mean generated power. The performance of the algorithm is assessed against two online reinforcement learning schemes: Q-learning and SARSA. In both regular and irregular waves, least-squares policy iteration outperforms the other strategies, especially when starting from unfavorable conditions for learning. Similar performance is observed for both basis functions, with a smaller number of radial basis functions underfitting the Q-function. The shorter learning time is fundamental for a practical application on a real wave energy converter. Furthermore, this paper shows that least-squares policy iteration is able to maximize the energy absorption of a wave energy converter despite strongly nonlinear effects due to its model-free nature, which removes the influence of modeling errors. Additionally, the floater geometry has been changed during a simulation to show that reinforcement learning control is able to adapt to variations in the system dynamics.
      PubDate: Oct. 2017
      Issue No: Vol. 8, No. 4 (2017)
  • Damping Inter-Area Oscillations With Large-Scale PV Plant by Modified
           Multiple-Model Adaptive Control Strategy
    • Authors: Lin Zhou;Xirui Yu;Bin Li;Chen Zheng;Jinhong Liu;Qiang Liu;Ke Guo;
      Pages: 1629 - 1636
      Abstract: Studies suggest that inter-area low-frequency oscillations can be damped with supplementary damping control of large-scale photovoltaic (PV) plants. Multiple-model adaptive control (MMAC) is applied as the damping strategy to deal with uncertain variations of the postdisturbance operating conditions. To reduce the scales of the model bank and the damper bank, K-means clustering algorithm is used taking inter-area modes as features for operating condition clustering, and a common damper is designed for each cluster. Based on the deviation between the output dynamic responses of the actual system and models, Bayesian approach is employed to calculate the probability of each model representing the actual system in real time, followed by updating weights of each damper's output. The weighted average of the individual damper's outputs is attached to the reactive power control of the PV plant. A new continuous form of probability calculation with an inertial link is proposed to smooth weight fluctuation caused by discrete calculation in conventional MMAC and ease stress of power regulation of the PV plant. The nonlinear simulation results demonstrate that the proposed control strategy is able to sufficiently damp the inter-area modes of interest in unexpected operating conditions without any prior knowledge about the postdisturbance state.
      PubDate: Oct. 2017
      Issue No: Vol. 8, No. 4 (2017)
  • A Combined Reliability Model of VSC-HVDC Connected Offshore Wind Farms
           Considering Wind Speed Correlation
    • Authors: Yifei Guo;Houlei Gao;Qiuwei Wu;
      Pages: 1637 - 1646
      Abstract: This paper proposes a combined reliability model of voltage source converter-based high voltage direct current (VSC-HVDC) connected offshore wind farms (WFs) using the frequency and duration technique. First, a two-dimensional multistate WF model is developed considering wind speed variations and WTGs outage. The wind speed correlation between different WFs is included in the two-dimensional multistate WF model by using an improved k-means clustering method. Then, the entire system with two WFs and a three-terminal VSC-HVDC system is modeled as a multistate generation unit. The proposed model is applied to the Roy Billinton test system for adequacy studies. Both the probability and frequency indices are calculated. The effectiveness and accuracy of the combined model is validated by comparing results with the sequential Monte Carlo simulation method. The effects of the outage of VSC-HVDC system and wind speed correlation on the system reliability were analyzed. Sensitivity analyses were conducted to investigate the impact of repair time of the offshore VSC-HVDC system on system reliability.
      PubDate: Oct. 2017
      Issue No: Vol. 8, No. 4 (2017)
  • Linear Operation of Photovoltaic Array With Directly Connected Lithium-Ion
    • Authors: Naoto Kakimoto;Ryo Asano;
      Pages: 1647 - 1657
      Abstract: This paper proposes linear operation of a photovoltaic array which is directly connected to lithium-ion batteries. The array voltage is fixed at the total battery voltage. When the amount of insolation is given, the array power decreases as the cell temperature rises. The maximum power point (MPP) voltage at the highest temperature of a year is selected as the array voltage. This voltage determines the optimal number of the batteries. The array power is guaranteed to be equal to the MPP power or greater through the year. Some simulation and experiment were executed to verify the effectiveness of the method. The utilization efficiency reaches 96.5%. The loss of power proved to be small compared with the maximum power point tracking, which can be economically recovered by using PV modules of larger capacity. A simple switch can substitute for a dc-dc converter.
      PubDate: Oct. 2017
      Issue No: Vol. 8, No. 4 (2017)
  • State of Charge Estimation of Vanadium Redox Flow Battery Based on Sliding
           Mode Observer and Dynamic Model Including Capacity Fading Factor
    • Authors: Binyu Xiong;Jiyun Zhao;Yixin Su;Zhongbao Wei;Maria Skyllas-Kazacos;
      Pages: 1658 - 1667
      Abstract: State of charge (SOC) of the batteries is a key indicator for battery monitoring and control. Long-term operation of vanadium redox flow batteries may cause ion diffusions across the membrane and the depletion of active materials, which will lead to capacity fading and increase in internal resistance. In previous studies, the capacity fading factor is not considered when designing the SOC estimation observer. This will cause a large error of SOC estimation if the capacity fading is significant. Thus, a selection of an adaptive SOC estimation method considering capacity fading factor is critical. In this paper, an adaptive observer-sliding mode observer-capable of monitoring SOC considering capacity factor is proposed based on a nonlinear electrical model. The observer is designed to adjust the capacity based on the decaying factor and compensate the error caused by the electrical model. A root mean square error of 0.013 V between the measured terminal voltage and estimated voltage is observed while a root mean square error of 0.12 V with the modeled voltage. The mean error between the observed and the modeled capacities is 0.14 Ah. The proposed method shows that the sliding mode observer could accurately estimate SOC with capacity fading.
      PubDate: Oct. 2017
      Issue No: Vol. 8, No. 4 (2017)
  • Design of Wind Turbine Dynamic Trip-Off Risk Alarming Mechanism for
           Large-Scale Wind Farms
    • Authors: Peng Liu;Zhengtian Li;Yixin Zhuo;Xiangning Lin;Suyang Ding;Muhammad Shoaib Khalid;Owolabi Sunday Adio;
      Pages: 1668 - 1678
      Abstract: The wind power in China is being developed mainly in terms of large scale, long distance, and high clustering. In this scenario, the uncertainty of wind farm operation gradually becomes a significant factor that power grid dispatcher needs to deal with. Among which, trip-off risk of wind turbine results from system disturbance, fault and fault removal of wind farm, etc. Besides, the geographical distribution of wind turbine usually also has the impact on the trip-off risk of wind farm. In view of above factors, existing security analysis methodology is difficult to satisfy the requirement of real-time alarming due to extreme analytical difficulty and huge computing complexity. Therefore, reasonable design of trip-off risk measure index of wind turbine becomes a key issue to implement a dynamic trip-off real-time alarming system. In this paper, a wind turbine trip-off decision tree system is constructed with the discrete characteristics of wind turbine distribution in wind farms taken into account. The decision trees can perform data mining using online information and make fast prediction on wind turbine voltage out-of-limit and trip-off situations under anticipated accident sets. The trip-off risk measure indexes are then output in light of the prediction results, which can provide intuitive risk level information and decision references for operators in wind farms and power systems. The results of case studies show that the proposed method can meet the requirement of prediction accuracy and resolve the contradictions between the amount of modeled nodes, the diversity of anticipated faults and the computation time when performing over-voltage early warning and control strategies.
      PubDate: Oct. 2017
      Issue No: Vol. 8, No. 4 (2017)
  • Aggregation of Distributed Energy Resources Under the Concept of
           Multienergy Players in Local Energy Systems
    • Authors: Maziar Yazdani-Damavandi;Nilufar Neyestani;Gianfranco Chicco;Miadreza Shafie-khah;João P. S. Catalão;
      Pages: 1679 - 1693
      Abstract: In recent years, in addition to the traditional aspects concerning efficiency and profitability, the energy sector is facing new challenges given by environmental issues, security of supply, and the increasing role of the local demand. Therefore, the researchers have developed new decision-making frameworks enabling higher local integration of distributed energy resources (DER). In this context, new energy players appeared in the retail markets, increasing the level of competition on the demand side. In this paper, a multienergy player (MEP) is defined, which behaves as a DER aggregator between the wholesale energy market and a number of local energy systems (LES). The MEP and the LES have to find a long-term equilibrium in the multienergy retail market, in which they are interrelated through the price signals. To achieve this goal, in this paper the decision-making conflict between the market players is represented through a bilevel model, in which the decision variables of the MEP at the upper level are parameters for the decision-making problem at the lower level (for the individual LES). The problem is transformed into a mathematical program with equilibrium constraints by implementing duality theory, which is solved with the CPLEX 12 solver. The numerical results show the different MEP behavior in various conditions that impact on the total flexibility of the energy system.
      PubDate: Oct. 2017
      Issue No: Vol. 8, No. 4 (2017)
  • Coordinated TCSC Allocation and Network Reinforcements Planning With Wind
    • Authors: Faruk Ugranli;Engin Karatepe;
      Pages: 1694 - 1705
      Abstract: Integration of wind power plants into power systems requires special attention on network planning to reduce curtailed wind energy as well as investment costs and generation costs. To this aim, in this study, transmission expansion planning, reactive power planning, and the allocation of TCSC devices are coordinated in order to minimize investment costs of transmission lines, reactive power sources, and TCSC devices along with the sum of generation costs and penalty for load curtailment. Installed wind power plants are modeled by using load-wind scenarios, which are obtained by clustering procedure. They are integrated into the constraints of the proposed method via linearized ac power flow equations. This assures keeping the proposed method as mixed-integer linear programming problem. The proposed method is applied to the Garver 6-bus and IEEE 24-bus RTS test systems under different case studies. Results prove the contributions of the coordinated network planning.
      PubDate: Oct. 2017
      Issue No: Vol. 8, No. 4 (2017)
  • Analysis of Series-DC Offshore Wind Plants with Aerodynamic Wake Effects
    • Authors: Michael H. Johnson;Dionysios C. Aliprantis;
      Pages: 1706 - 1714
      Abstract: In series-dc wind plants, variations in power output among turbines due to aerodynamic effects may lead to violations of operational limits of electric machines and power electronic converters. Turbine wakes constitute the predominant cause of such variations. It is, therefore, imperative to incorporate wake models during analysis of wind plant-level issues and control strategies. In this paper, two candidate energy conversion configurations previously proposed for series-dc connected turbines are considered. They are analyzed in the context of a notional offshore wind plant using the Jensen wake model. An optimization problem is formulated for maximizing total plant power output. A key finding is that this objective is attainable without any turbine violating operational limits for arbitrary wind direction and speed. This, however, may require variation of transmission voltage or current as a function of prevailing wind conditions by means of the onshore converter interfacing the plant with the terrestrial power grid.
      PubDate: Oct. 2017
      Issue No: Vol. 8, No. 4 (2017)
  • Multi-Agent Optimal Allocation of Energy Storage Systems in Distribution
    • Authors: Yu Zheng;David J. Hill;Zhao Yang Dong;
      Pages: 1715 - 1725
      Abstract: A variety of optimal methods for the allocation of a battery energy storage system (BESS) have been proposed for a distribution company (DISCO) to mitigate the transaction risk in a power market. All the distributed devices are assumed to be owned by the DISCO. However, in future power systems, more parties in a distribution system will have incentives to integrate BESS to reduce operational cost. In this paper, an enhanced BESS optimal allocation method is proposed for multiple agents in a distribution system. First, the electricity market mechanism is extended to a distribution system, and the corresponding energy transaction process is modeled for different agents, such as wind farms, solar power stations, demand aggregators, and the DISCO. The uncertainties of renewable energy and demand are addressed using stochastic methods. In the proposed transaction model, the integration of BESS can help an agent to reduce the operational cost, also defined as the payoff function. Next, game theory is introduced in this paper to investigate the interactions among the agents and to determine the BESS integration plans. The agents are built as players who are willing to minimize their payoff functions in the proposed non-cooperative game. The Nash equilibrium, which is the best strategy for the players, is proved to exist. Such equilibrium can be solved using an iterative algorithm. The proposed BESS allocation method for the multi-agent system is verified for two cases, and the payoff reductions are quantified based on the proposed distribution energy transaction mechanism.
      PubDate: Oct. 2017
      Issue No: Vol. 8, No. 4 (2017)
  • Operation Scheduling of Battery Storage Systems in Joint Energy and
           Ancillary Services Markets
    • Authors: Mostafa Kazemi;Hamidreza Zareipour;Nima Amjady;William D. Rosehart;Mehdi Ehsan;
      Pages: 1726 - 1735
      Abstract: This paper presents a risk-based approach for evaluating the participation strategy of a battery storage system in multiple markets. Simultaneous offering in day-ahead energy, spinning reserve, and regulation markets is considered in this paper. The uncertainties considered include predicted market prices as well as energy deployment in spinning reserve and regulation markets. A new nonprobabilistic model is introduced in this paper to handle the uncertain nature of spinning reserve and regulation markets. Robust optimization is implemented to model these uncertain parameters and manage their related risk. The proposed risk-based model is a max-min problem, which is converted to its equivalent ordinary maximization problem using duality theory. The presented model is linearized by implementing strong duality theory. Finally, the proposed method is tested and verified using an illustrative case study.
      PubDate: Oct. 2017
      Issue No: Vol. 8, No. 4 (2017)
  • Lifetime Test Design for Second-Use Electric Vehicle Batteries in
           Residential Applications
    • Authors: He Li;Mohammed Alsolami;Shaobing Yang;Yazan M. Alsmadi;Jin Wang;
      Pages: 1736 - 1746
      Abstract: This paper provides a comprehensive study on the lifetime test design of second-use electric vehicle plug-in hybrid electric vehicle ((PHEV)/hybrid electric vehicle(HEV)/battery electric vehicle(BEV)) batteries as the residential application. The work starts by modeling a realistic operation environment for the second-use batteries. As a residential application, the battery pack usage profile was simulated in detail with proposed steps and parameters. The paper then presents design procedures for transferring simulated battery pack usage profile into a lifetime test profile. Finally, a lifetime test case study is performed on a second-use PHEV (Ford C-max) battery pack. The extraction of the residential application usage profile, the configuration of the test platform, and the 150-h demonstration test results together explain the proposed test methodology.
      PubDate: Oct. 2017
      Issue No: Vol. 8, No. 4 (2017)
  • A Versatile Mixture Distribution and Its Application in Economic Dispatch
           with Multiple Wind Farms
    • Authors: Chenghui Tang;Jian Xu;Yuanzhang Sun;Ji Liu;Xiong Li;Deping Ke;Jun Yang;Xiaotao Peng;
      Pages: 1747 - 1762
      Abstract: An improved versatile distribution for wind power is proposed, with higher representation accuracy and more suitable applications in economic dispatch (ED) compared with Versatile distribution. Further, versatile mixture distribution (VMD) is proposed to represent all possible wind power distribution with customized arbitrary errors. Compared with Gaussian Mixture distribution (GMD), it has more flexible forms and can represent wind power more accurately. Its cumulative distribution function has analytical forms with higher computational efficiency. Then, real-time dynamic ED model and algorithm based on VMD with multiple wind farms (WFs) is proposed. Based on the VMD model, the probability distributions of wind power of each WF and the summation of all WFs are modeled. The ED model and algorithm solve the problem of the correlation of multiple renewable energy random variables with high computation efficiency for real-time ED. The results show that compared with GMD or unimodal distributions, VMD can represent wind power more accurately and can greatly simplify and speed up the ED model and algorithm. Compared with other methods for multiple renewable energy random variables, the proposed model and algorithm can improve economy significantly.
      PubDate: Oct. 2017
      Issue No: Vol. 8, No. 4 (2017)
  • Model-Based MPPT for Shaded and Mismatched Modules of Photovoltaic Farm
    • Authors: S. Berclin Jeyaprabha;A. Immanuel Selvakumar;
      Pages: 1763 - 1771
      Abstract: Photovoltaic modules (PVM) of same rating and manufacturer have unique characteristics in real time due to manufacturing dispersion. This unique maximum power point (MPP) of each module is tracked by the proven distributed module level maximum power point tracking (DMMPPT). Since the conventional slow iterative MPPT algorithms in DMMPPT fail under the rapidly varying environmental conditions, the model-based algorithm (MBA) is used in this paper due to its swift tracking and character leaning nature. By identifying the actual behavior of each module, the new MBA is implemented here in compensation power dc-dc converter for the distributed model-based maximum power point tracking (CPDC-DMBMPPT). The flyback converter-based CPDC converter, which provides the current or voltage compensation is used to operate the module in its own MPP without any compromise even at the mismatched or partial shaded condition. As the individual module parameters used in MBA are estimated during the installation, the costly high precision measuring instruments are avoided in the consumer site. Also, due to the LabVIEW-based centralized control, updates in the MBA becomes easy without changing the individual controllers in Photovoltaic farms. The proposed methodology and its proven outcomes are discussed through the simulation and hardware outputs.
      PubDate: Oct. 2017
      Issue No: Vol. 8, No. 4 (2017)
  • Modification of DFIG's Active Power Control Loop for Speed Control
           Enhancement and Inertial Frequency Response
    • Authors: Alireza Ashouri-Zadeh;Mohammadreza Toulabi;Shahab Bahrami;Ali Mohammad Ranjbar;
      Pages: 1772 - 1782
      Abstract: This paper proposes a fuzzy-based speed controller for the doubly fed induction generator (DFIG)-based wind turbines with the rotor speed and wind speed inputs. The controller parameters are optimized using the particle swarm optimization algorithm. To accelerate tracking the maximum power point trajectory, the conventional controller is augmented with a feed-forward compensator, which uses the wind speed input and includes a high-pass filter. The proposed combined speed controller is robust against wind measurement errors and as the accuracy of anemometers increases the speed regulation tends toward the ideal controller. The cutoff frequency of the applied filter is determined considering a compromise between the sensitivity to measurement errors and speed of regulation process. We also design an auxiliary frequency controller to equip the DFIGs with an inertial frequency response. In the proposed controller, two important constraints are taken into account: the feasible rotor speed range during the injection period, and the minimum time to recover the DFIG's speed. The impacts of the proposed controllers are evaluated through extensive time-domain simulations on an IEEE 9-bus test system using the DIgSILENT/PowerFactory software. Results confirm the effectiveness of the proposed controllers in serious transients and load disturbances.
      PubDate: Oct. 2017
      Issue No: Vol. 8, No. 4 (2017)
  • Four-Parameter Models for Wind Farm Power Curves and Power Probability
           Density Functions
    • Authors: Andrés Feijóo;Daniel Villanueva;
      Pages: 1783 - 1784
      Abstract: This letter is an additional contribution to the calculation of wind farm power curves and power probability density functions with the help of the logistic function and Jensen's model for wake effect calculation. The goal is to complete a previous formulation based on the use of the 3P-DP logistic function, with two other, called the 4P-DS and the 4P-DP ones.
      PubDate: Oct. 2017
      Issue No: Vol. 8, No. 4 (2017)
School of Mathematical and Computer Sciences
Heriot-Watt University
Edinburgh, EH14 4AS, UK
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