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Showing 1 - 103 of 103 Journals sorted alphabetically
3C TIC     Open Access   (Followers: 1)
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: 2)
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: 11)
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: 16)
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: 12)
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: 60)
IEEE Electrical Insulation Magazine     Full-text available via subscription   (Followers: 27)
IEEE Signal Processing Magazine     Full-text available via subscription   (Followers: 66)
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: 7)
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: 11)
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: 7)
International Journal of Electrical Engineering Education     Hybrid Journal   (Followers: 6)
International Journal of Electrical Power & Energy Systems     Open Access   (Followers: 20)
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: 6)
International Journal of Nuclear Security     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: 18)
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: 6)
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)
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: 4)
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: 1)
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  
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: July 2017
      Issue No: Vol. 8, No. 3 (2017)
  • 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: July 2017
      Issue No: Vol. 8, No. 3 (2017)
  • Information for Authors
    • Abstract: These instructions give guidelines for preparing papers for this publication. Presents information for authors publishing in this journal.
      PubDate: July 2017
      Issue No: Vol. 8, No. 3 (2017)
  • Solar Irradiance Forecasting in Remote Microgrids Using Markov Switching
    • Authors: Ayush Shakya;Semhar Michael;Christopher Saunders;Douglas Armstrong;Prakash Pandey;Santosh Chalise;Reinaldo Tonkoski;
      Pages: 895 - 905
      Abstract: Photovoltaic (PV) systems integration is increasingly being used to reduce fuel consumption in diesel-based remote microgrids. However, uncertainty and low correlation of PV power availability with load reduces the benefits of PV integration. These challenges can be handled by introducing reserve. However, this leads to increased operational cost. Solar irradiance forecasting helps to reduce reserve requirement, thereby improving the utilization of PV energy. This paper presents a new solar irradiance forecasting method for remote microgrids based on the Markov switching model. This method uses locally available data to predict one-day-ahead solar irradiance for scheduling energy resources in remote microgrids. The model considers past solar irradiance data, clear sky irradiance, and Fourier basis expansions to create linear models for three regimes or states: high, medium, and low energy regimes for days corresponding to sunny, mildly cloudy, and extremely cloudy days, respectively. The case study for Brookings, SD, USA, discussed in this paper, resulted in an average mean absolute percentage error of 31.8% for five years, from 2001 to 2005, with higher errors during summer months than during winter months.
      PubDate: July 2017
      Issue No: Vol. 8, No. 3 (2017)
  • Optimal Resource Allocation and Charging Prices for Benefit Maximization
           in Smart PEV-Parking Lots
    • Authors: Ahmed S. A. Awad;Mostafa F. Shaaban;Tarek H. M. EL-Fouly;Ehab F. El-Saadany;Magdy M. A. Salama;
      Pages: 906 - 915
      Abstract: The emerging interest in deployment of plug-in electric vehicles (PEVs) in distribution networks represents a great challenge to both system planners and owners of PEV-parking lots. The owners of PEV-parking lots might be interested in maximizing their profit via installing charging units to supply the PEV demand. However, with stringent rules of network upgrades, installing these charging units would be very challenging. Network constraints could be relaxed via controlling the net demand through integrating distributed generation (DG) and/or storage units. This paper presents an optimization model for determining the optimal mix of solar-based DG and storage units, as well as the optimal charging prices for PEVs. The main objective is to maximize the benefit of the PEV-parking lot's owner without violating system constraints. Two cases are considered in this paper: uncoordinated and coordinated PEV demand. A novel mathematical model is further developed whereby the behavior of vehicles' drivers, in response to different charging prices, is considered in generating the energy consumption of PEVs.
      PubDate: July 2017
      Issue No: Vol. 8, No. 3 (2017)
  • An Adaptive Feedback Linearization Approach to Inertial Frequency Response
           of Wind Turbines
    • Authors: Mohammadreza Toulabi;Ahmad Salehi Dobakhshari;Ali Mohammad Ranjbar;
      Pages: 916 - 926
      Abstract: Synthetic inertial frequency response has attracted increasing attention due to the paradigm shift in power generation from synchronous generators toward wind turbines. This paper presents a novel nonlinear controller to enable inertial response of a variable speed wind turbine (VSWT). The VSWT has a nonlinear model which cannot efficiently be dealt with by linear control techniques as it may experience large deviations from its operating point during the frequency support period. To design the controller, a nonlinear model for the wind turbine together with power system is utilized. The output power of the wind turbine is expressed in terms of the state variables, and its exact Taylor series expansion is used in control design procedure. A regular controller is first designed based on the input-output feedback linearization approach. Then, the regular controller is replaced by an adaptive one to accommodate parameter variations of VSWT. The proposed controller is then embedded in the detailed model of the VSWT in MATLAB/Simulink environment. Extensive investigations, including the effects of different controller parameters, are carried out. Impacts of the most important practical operational constraints in the VSWT inertia response are also analyzed. Results verify the superiority and appropriateness of the proposed controller.
      PubDate: July 2017
      Issue No: Vol. 8, No. 3 (2017)
  • A Developed Integrated Scheme Based Approach for Wind Turbine Intelligent
    • Authors: Tawfek K. Mahmoud;Zhao Yang Dong;Jin Ma;
      Pages: 927 - 937
      Abstract: A doubly fed induction generator has been widely used for extracting wind energy using variable speed wind turbines. In this paper, a developed integrated intelligent automatic control system is proposed to increase the extracting energy as well as to improve the power system performance. The controller is decomposing and grouping the sensing wind speed time series via a high-accuracy anemometer into components of reduced-order complexity using the complete ensemble empirical mode decomposition with adaptive noise and approximate entropy techniques. The output signal is applied to extreme learning machines as a real-time predictive control system. Artificial neural network, fuzzy controller, and support vector machines models are used for comparison and model validity as well as accuracy. The developed integrated PowerFactory-MATLAB simulation tool is used for obtaining, testing, and adjusting optimum wind turbine speed based on the real and predictive wind speed values in the way that increase the extracting energy by using a hybrid predictive-maximum power point tracker. The selected model that connects inputs-outputs is determined during the offline training period and, then, the predictive controller is determined online using the instantaneous inputs values. The efficiency of the developed model is verified by applying it to real wind speed data from Australia and the National Renewable Energy Laboratory. The simulation results display an excellent performance of the measured generator speed, voltage, current, active, and reactive power in addition to wind turbine power as well as a pitch angle during transient and steady-state conditions. The experimental results have verified the validity and accuracy of the developed approach and the control algorithms for practical applications.
      PubDate: July 2017
      Issue No: Vol. 8, No. 3 (2017)
  • Real-Time Integration of Intermittent Generation With Voltage Rise
    • Authors: Pirathayini Srikantha;Deepa Kundur;
      Pages: 938 - 952
      Abstract: In the modern electric power grid, a commonly observable recent phenomenon is the increasing penetration of renewable generation sources especially at the distribution network (DN) level. The traditional DN is not designed for bidirectional power flow induced by these volatile sources and, therefore voltage rise is a major concern. In order to enable mass renewable integration into any type of existing radial DN without requiring expensive line/bus upgrades and avoiding adverse effects of voltage rise, these generation sources (with possible nonconvex discrete output levels) must be dispatched in real-time while taking into account nonconvex voltage constraints. Ubiquitous connectivity between power components is available in today's grid due to the cyber-physical nature of these devices. We leverage this to propose a distributed algorithm based on principles of population games for efficient dispatch that minimizes dependence of the DN on the main grid for sustainable system operation. Theoretical and simulation studies show that the proposed algorithm allows for the seamless coexistence of a large number of renewables that are highly responsive to fluctuations in demand and supply with strong convergence properties while successfully mitigating voltage rise issues.
      PubDate: July 2017
      Issue No: Vol. 8, No. 3 (2017)
  • Thermal and Reliability Assessment for Wind Energy Systems With DSTATCOM
           Functionality in Resilient Microgrids
    • Authors: Mokhtar Aly;Emad M. Ahmed;Masahito Shoyama;
      Pages: 953 - 965
      Abstract: Different functionalities can be incorporated into wind energy conversion systems (WECSs) in resilient microgrids in order to reduce the total system cost and to assist their self-healing capability. Meanwhile, wind industry-based reliability surveys have addressed that power electronics components are the most vulnerable parts in WECS. Therefore, thermal stresses and lifetime consumption of WECS are critical factors for evaluating the added functionalities and for developing new control strategies as well. Almost all of the previous methodologies in the literature tackle the problem of lifetime assessment of WECS using only the behavior of wind generation profiles and reactive power injection, which is limited by grid codes. Subsequently, these approaches cannot efficiently achieve lifetime assessment in case of resilient microgrid operation and different load demands. This paper proposes a more convenient approach for thermal behavior, and lifetime assessment for WECSs that considers the influence of the added DSTATCOM functionality, and various modes of resilient microgrids operation. Moreover, the proposed approach utilizes a joint probability distribution function (JPDF) that combines both of the collected field data of wind generation and load demand levels as well. The feasibility of the proposed approach has been verified analytically and compared to the previously addressed approaches. It can be concluded that thermal behavior and reliability assessment of WECS are highly impacted by the added DSTATCOM functionality.
      PubDate: July 2017
      Issue No: Vol. 8, No. 3 (2017)
  • Improved Cycle Control and Sizing Scheme for Wind Energy Storage System
           Based on Multiobjective Optimization
    • Authors: Feng Zhang;Guibin Wang;Ke Meng;Junhua Zhao;Zhao Xu;Zhao Yang Dong;Jun Liang;
      Pages: 966 - 977
      Abstract: This paper proposes an improved control and sizing scheme for a wind energy storage system for wind smoothing. Considering the trading rules in the electricity market, a cycle control strategy with progressive cycle period including one charge and discharge period is proposed. To determine the reference output and time duration of each cycle control period, a multiobjective optimization model is presented considering both the maximum of time duration of each cycle control period and the minimum of power variation between adjacent charge and discharge intervals. In the proposed control strategy, wind power is smoothed with flexible reference output and self-adjustable battery state of charge ranges, and then, the battery can be utilized without overdischarge. Meanwhile, the smoothed wind power with longer average interval duration can better benefit the wind power trading in electricity market. Besides, the charge/discharge switch can be significantly decreased to prolong the battery lifetime. Afterward, based on the presented control strategy, the sizing methodology is proposed according to the cumulative probability function of the charge/discharge power and energy. Moreover, the impact of wind power forecast error is also considered in the real-time operation. By using actual wind power data, case studies are fulfilled to validate the performance of the proposed cycle control and sizing strategy.
      PubDate: July 2017
      Issue No: Vol. 8, No. 3 (2017)
  • Storage Sizing With Peak-Shaving Policy for Wind Farm Based on Cyclic
           Markov Chain Model
    • Authors: Jiaojiao Dong;Feng Gao;Xiaohong Guan;Qiaozhu Zhai;Jiang Wu;
      Pages: 978 - 989
      Abstract: Due to the intermittent nature of wind power, large-scale wind farm integration creates technical challenges, such as increase of peak/valley net load difference and uncertainty of generation. Energy storage is essential in providing flexibility and ensuring system reliability. Storage sizing problem is widely studied for a given demand curve, and the needed storage capacity to achieve a certain level of peak-shaving performance is not analyzed. In this paper, a probabilistic model of storage sizing with peak-shaving policy optimization under required matching probability is established to minimize net cost considering time-variant energy price. Storage is used not only for reducing energy deficit and keeping generation reliable but also for energy shifting to obtain higher profit. A cyclic nonhomogeneous Markov chain (CNHMC) steady-state analysis method is proposed, serving as a more efficient way to test probability constraint than commonly used time-consuming sequential Monte-Carlo simulation. CNHMC is used in stored power modeling representing diurnal variation of wind power and load. Probability constraint is tested by obtained analytical expression of matching probability. Numerical test shows that reliable power supply is achieved with little profit sacrifice, peak/valley net load difference decreases with little increment on storage capacity, and the proposed solution method is fast and accurate.
      PubDate: July 2017
      Issue No: Vol. 8, No. 3 (2017)
  • Power Smoothing of a Variable-Speed Wind Turbine Generator in Association
           With the Rotor-Speed-Dependent Gain
    • Authors: Yeonhee Kim;Moses Kang;Eduard Muljadi;Jung-Wook Park;Yong Cheol Kang;
      Pages: 990 - 999
      Abstract: This paper proposes a power-smoothing scheme for a variable-speed wind turbine generator (WTG) that can smooth out the WTG's fluctuating power caused by varying wind speeds, and thereby keep the system frequency within a narrow range. The proposed scheme employs an additional loop based on the system frequency deviation that operates in conjunction with the maximum power point tracking (MPPT) control loop. Unlike the conventional, fixed-gain scheme, its control gain is modified with the rotor speed. In the proposed scheme, the control gain is determined by considering the ratio of the output of the additional loop to that of the MPPT loop. To improve the contribution of the scheme toward maintaining the frequency while ensuring the stable operation of WTGs, in the low rotor speed region, the ratio is set to be proportional to the rotor speed; in the high rotor speed region, the ratio remains constant. The performance of the proposed scheme is investigated under varying wind conditions for the IEEE 14-bus system. The simulation results demonstrate that the scheme successfully operates regardless of the output power fluctuation of a WTG by adjusting the gain with the rotor speed, and thereby improves the frequency-regulating capability of a WTG.
      PubDate: July 2017
      Issue No: Vol. 8, No. 3 (2017)
  • Dependent Discrete Convolution Based Probabilistic Load Flow for the
           Active Distribution System
    • Authors: Yi Wang;Ning Zhang;Qixin Chen;Jingwei Yang;Chongqing Kang;Junhui Huang;
      Pages: 1000 - 1009
      Abstract: Active distribution system (ADS) plays a significant role in enabling the integration of distributed generation. The stochastic nature of renewable energy resources injects the complex uncertainties of power flow into ADS. This paper proposes a discrete convolution methodology for probabilistic load flow (PLF) of ADS considering correlated uncertainties. First, the uncertainties of load and renewable energy are modeled using the distribution of the corresponding forecasting error, and the correlation is formulated using a Copula function. A novel reactive power-embedded DC power flow model with high accuracy in both branch flow and node voltage is introduced into ADS. Finally, the distribution of power flow is calculated using dependent discrete convolution, which is capable of handling nonanalytical probability distribution functions. In addition, a reduced dimension approximation method is proposed to further reduce the computational burden. The proposed PLF algorithm is tested on the IEEE 33-nodes system and 123-nodes system, and the results show that the proposed methodology requires less computation and produces higher accuracy compared with current methods.
      PubDate: July 2017
      Issue No: Vol. 8, No. 3 (2017)
  • On Distributed PV Hosting Capacity Estimation, Sensitivity Study, and
    • Authors: Fei Ding;Barry Mather;
      Pages: 1010 - 1020
      Abstract: This paper first studies the estimated distributed photovoltaic (PV) hosting capacities of 17 utility distribution feeders using the Monte Carlo simulation based stochastic analysis, and then analyzes the sensitivity of PV hosting capacity to both feeder and PV system characteristics. Furthermore, an active distribution network management approach is proposed to maximize PV hosting capacity by optimally switching capacitors, adjusting voltage regulator taps, managing controllable branch switches, and controlling smart PV inverters. The approach is formulated as a mixed-integer nonlinear optimization problem and a genetic algorithm is developed to obtain the solution. Multiple simulation cases are studied and the effectiveness of the proposed approach on increasing PV hosting capacity is demonstrated.
      PubDate: July 2017
      Issue No: Vol. 8, No. 3 (2017)
  • Worst-Case Photovoltaic Generation and Power Change Distribution Under
           Dense Cloud Cover
    • Authors: Sanjoy Roy;
      Pages: 1021 - 1028
      Abstract: Photovoltaic (PV) power generation units located in tropical or equatorial sites frequently experience low-lying, dense cloud cover; and are thereby exposed to rapid real time changes in irradiance. Commonly referred to as cloud transients, the changes lead to short duration power variations and substantial reduction of output from individual units. The paper proposes pessimistic (or worst-case) analytical assessment of power variation statistics at a PV generation unit, as well as the consequent drop in output power. Statistical estimates are introduced for worst-case short duration mean output power, its temporal variability, and the associated power change distribution. The metrics are verified against ensemble estimates from field studies conducted in Brazil and India. Statistical estimates have the advantage of exclusive parametric dependence on optical air mass, which makes them applicable across diverse geography and climate. They can therefore be used for quick evaluation of short duration performance as well as comparative studies, both at existing as well as prospective PV generating stations.
      PubDate: July 2017
      Issue No: Vol. 8, No. 3 (2017)
  • Hierarchical Optimization for the Double-Sided Ring Structure of the
           Collector System Planning of Large Offshore Wind Farms
    • Authors: Shurong Wei;Lu Zhang;Yao Xu;Yang Fu;Fangxing Li;
      Pages: 1029 - 1039
      Abstract: High reliability double-sided ring collector systems have been applied in practice for long distance and off the coast large-capacity offshore wind farms. To reduce investment and improve reliability, it is important to optimize and evaluate the double-sided ring collector systems. In this paper, a capital cost optimization model is developed to solve the mutual coupling effects among the system structure, power flow, and short circuit current in the collector system constraints. Based on the characteristics of the offshore electrical collector systems, the optimization model is divided into the offshore substation layer, the wind turbine layer, and the submarine cable layer. The fuzzy clustering algorithm, single parent genetic algorithm, and multiple traveling salesman solution technique are integrated and applied to solve the hierarchical optimization model. Finally, the proposed model and the optimization algorithms are tested in a real, large-scale offshore wind farm. The simulation results are compared with the radial collector systems from an economics and reliability point of view. The simulation results show that the double-sided ring design will achieve more profit with higher reliability in the long run. The results can also provide a benchmark for the collector system design of large-scale offshore wind farms.
      PubDate: July 2017
      Issue No: Vol. 8, No. 3 (2017)
  • Effect of Risk Aversion on Reserve Procurement With Flexible Demand Side
           Resources From the ISO Point of View
    • Authors: Nikolaos G. Paterakis;Agustín A. Sánchez de la Nieta;Anastasios G. Bakirtzis;Javier Contreras;João P. S. Catalão;
      Pages: 1040 - 1050
      Abstract: In this study, a two-stage stochastic programming joint day-ahead energy and reserve scheduling model to address uncertainty in wind power generation is developed. Apart from the generation side, the demand side is also eligible as a reserve resource and is modeled through responsive load aggregations, as well as large industrial loads that directly participate in the scheduling procedure. The main contribution of this paper is the inclusion of a risk metric, namely the conditional value-at-risk, which renders a conceptually different resource scheduling framework. The proposed model is employed in order to analyze the behavior of energy and reserve scheduling by both generation and demand for a risk-averse independent system operator. To reach practical conclusions, the proposed methodology is tested on the real non-interconnected insular power system of Crete, Greece, which is characterized by a significant penetration of wind power generation.
      PubDate: July 2017
      Issue No: Vol. 8, No. 3 (2017)
  • Model Predictive Control of LPC-Looped Active Distribution Network With
           High Penetration of Distributed Generation
    • Authors: Xuetao Xing;Jin Lin;Can Wan;Yonghua Song;
      Pages: 1051 - 1063
      Abstract: Loop power flow controller (LPC) enables closed-loop operations of active distribution network at medium-voltage level to maximize network utilization and to mitigate power variations under high penetration of distributed generation. The operation strategy of LPC plays a key role to enhance the security and efficiency of LPC-looped active distribution network (LPC-ADN). This paper develops a comprehensive model predictive control (MPC) model for LPC-ADN to timely respond to operation statuses and output variations of distributed generations under security constraints over multiple operation periods. Multiterminal LPCs are innovatively applied to active distribution network in this study. An improved double description approximation method is proposed to transform nonconvexity security constraints of LPC-ADN into a set of linear constraints. Network regulations, such as tap changing, are appropriately integrated into the comprehensive model and coordinated with LPC actions to balance loads of feeder lines with distributed generations. Two test systems with 32 and 123 nodes are used to verify the accuracy and effectiveness of the proposed MPC model of LPC-ADN.
      PubDate: July 2017
      Issue No: Vol. 8, No. 3 (2017)
  • Wind-Friendly Flexible Ramping Product Design in Multi-Timescale Power
           System Operations
    • Authors: Mingjian Cui;Jie Zhang;Hongyu Wu;Bri-Mathias Hodge;
      Pages: 1064 - 1075
      Abstract: With increasing wind power penetration in the electricity grid, system operators are recognizing the need for additional flexibility, and some are implementing new ramping products as a type of ancillary service. However, wind is generally thought of as causing the need for ramping services, not as being a potential source for the service. In this paper, a multi-timescale unit commitment and economic dispatch model is developed to consider the wind power ramping product (WPRP). An optimized swinging door algorithm with dynamic programming is applied to identify and forecast wind power ramps (WPRs). Designed as positive characteristics of WPRs, the WPRP is then integrated into the multi-timescale dispatch model that considers new objective functions, ramping capacity limits, active power limits, and flexible ramping requirements. Numerical simulations on the modified IEEE 118-bus system show the potential effectiveness of WPRP in increasing the economic efficiency of power system operations with high levels of wind power penetration. It is found that WPRP not only reduces the production cost by using less ramping reserves scheduled by conventional generators, but also possibly enhances the reliability of power system operations. Moreover, wind power forecasts play an important role in providing high-quality WPRP service.
      PubDate: July 2017
      Issue No: Vol. 8, No. 3 (2017)
  • Conservation Voltage Reduction for Autonomous Microgrids Based on
           V–I Droop Characteristics
    • Authors: Aisha Munawer Pasha;Hatem H. Zeineldin;Ameena Saad Al-Sumaiti;Mohamed Shawky El Moursi;Ehab Fahamy El Sadaany;
      Pages: 1076 - 1085
      Abstract: Conventional droop characteristics for microgrids have been primarily proposed to achieve proper load sharing between the various distributed generation units. This paper proposes a different perspective for designing autonomous microgrids, which aims at reducing the power consumption of the microgrid by utilizing the concept of conservation voltage reduction. The proposed control strategy relies on a voltage-current (V-I ) droop characteristic, designed to perform demand side management through voltage control. The effectiveness of the proposed control scheme is demonstrated through time-domain simulation studies considering voltage dependent loads tested over a range of loading conditions and power factors. The performance of the proposed scheme is compared to the conventional and adaptive P-f/Q-V decentralized droop control. Further, a comparison of the transient analysis of the three droop schemes in case of a fault has been evaluated. The proposed V-I droop control scheme can maximize the number of loads being supplied during power shortage.
      PubDate: July 2017
      Issue No: Vol. 8, No. 3 (2017)
  • A Novel DC Fault Ride-Through Scheme for MTDC Networks Connecting
           Large-Scale Wind Parks
    • Authors: Wasiu Sanusi;Mohamed Al Hosani;Mohamed Shawky El Moursi;
      Pages: 1086 - 1095
      Abstract: This paper proposes a novel fault ride-through protection scheme for multiterminal dc (MTDC) networks connecting large-scale offshore wind parks. The proposed scheme introduces an MTDC network with a hybrid fault current limiter (FCL), which consists of a high-temperature superconducting FCL (HTS-FCL) and series braking resistor (SBR) integrated with low-loss mechanical dc circuit breaker (DCCB). The aim of HTS-FCL is to provide fast quenching, limit the dc fault current within the interrupting capacity of the DCCB, and reduce the dc fault current to certain levels such that converters can sustain prolonged periods of operation without blocking. Also, SBR allows automatic reclosing of DCCBs following a temporary fault, thereby enhancing the network security and reliability. Mechanical DCCBs with the proposed hybrid limiter are installed at the terminating points of each dc cable. The proposed protection scheme is based on differential current approaches with fault clearing time of few milliseconds, which gives enhanced network selectivity and reliability. A four-terminal meshed MTDC network with the proposed hybrid FCL is modeled in PSCAD/EMTDC. The obtained simulation results confirm successful dc fault isolation and network recovery for different dc fault scenarios.
      PubDate: July 2017
      Issue No: Vol. 8, No. 3 (2017)
  • Multisampling Maximum Power Point Tracker (MS-MPPT) to Compensate
           Irradiance and Temperature Changes
    • Authors: Gerardo Escobar;Sami Pettersson;Carl Ngai Man Ho;Roberto Rico-Camacho;
      Pages: 1096 - 1105
      Abstract: This paper presents a maximum power point tracking (MPPT) method that compensates fast, though smooth, irradiance (or temperature) changes. The proposed method belongs to the family of perturb and observe (P&O) methods as the photovoltaic (PV) voltage is intentionally perturbed to induce changes on the PV power. In consequence, the slope of the pv-characteristic curve can be detected, which reveals the MPP position. The perturbation is usually an increment with varying direction, which is used to update the next PV voltage reference. However, changes on irradiance (or temperature) may also cause changes on the PV power, which mix with the algorithm's intentional increment effect on the PV power. This combination of effects confuses the slope detection, which may entail a wrong decision on the next increment direction, and a considerable deviation from the MPP. The scheme presented here proposes the use of more samplings and an associated combination of increments directions before taking a decision. This additional information is used to separate the effect of irradiance (or temperature) changes from the algorithm's intentional perturbation effect. Thus, the proposed multisampling MPPT can provide effective MPP tracking despite of irradiance (or temperature) changes. The proposed scheme is experimentally tested and compared to the conventional P&O under irradiance changes.
      PubDate: July 2017
      Issue No: Vol. 8, No. 3 (2017)
  • Look-Ahead Bidding Strategy for Energy Storage
    • Authors: Yishen Wang;Yury Dvorkin;Ricardo Fernández-Blanco;Bolun Xu;Ting Qiu;Daniel S. Kirschen;
      Pages: 1106 - 1117
      Abstract: As the cost of battery energy storage continues to decline, we are likely to see the emergence of merchant energy storage operators. These entities will seek to maximize their operating profits through strategic bidding in the day-ahead electricity market. One important parameter in any storage bidding strategy is the state-of-charge at the end of the trading day. Because this final state-of-charge is the initial state-of-charge for the next trading day, it has a strong impact on the profitability of storage for this next day. This paper proposes a look-ahead technique to optimize a merchant energy storage operator's bidding strategy considering both the day-ahead and the following day. Taking into account the discounted profit opportunities that could be achieved during the following day allows us to optimize the state-of-charge at the end of the first day. We formulate this problem as a bilevel optimization. The lower-level problem clears a ramp-constrained multiperiod market and passes the results to the upper-level problem that optimizes the storage bids. Linearization techniques and Karush-Kuhn-Tucker conditions are used to transform the original problem into an equivalent single-level mixed-integer linear program. Numerical results obtained with the IEEE Reliability Test System demonstrate the benefits of the proposed look-ahead bidding strategy and the importance of considering ramping and network constraints.
      PubDate: July 2017
      Issue No: Vol. 8, No. 3 (2017)
  • Statistical Analysis of a 1:7 Scale Field Test Wave Energy Converter Using
    • Authors: Ratanak So;Carlos Michelen;Bret Bosma;Pukha Lenee-Bluhm;Ted K. A. Brekken;
      Pages: 1118 - 1126
      Abstract: This study uses the open-source wave energy converter simulator (WEC-Sim) code to model the Columbia Power Technologies SeaRay 1:7 scale WEC. WEC-Sim is intended to run quickly on standard desktop equipment and provide a very gentle learning curve for WEC modeling. This paper focuses on the linear implementation of WEC-Sim as that requires the least simulation time and is often the starting point for basic system design. WECSim results are compared against the SeaRay experimental data. Two studies were conducted: A comparison of WEC-Sim predications versus experimental data across 285 trials of varying sea states to determine the overall average power and energy production; and a determination of WEC-Sim's accuracy in predicting the experimental ranges of position, speed, torque, and power. The study of average power production across many sea states shows that the WEC-Sim predicts the average power of the aft float well, within 15%, but the error in the fore float is larger at 34%. The error in total predicted power is 24%. The detailed analysis of range of motion shows WEC-Sim predicted 95th percentile outliers (which dominate the design considerations) in position, speed, and torque by +15%, +14%, and +17%, respectively, for the fore float and -1%, -9%, and -6%, respectively, for the aft float.
      PubDate: July 2017
      Issue No: Vol. 8, No. 3 (2017)
  • New Voltage Control Strategies for VSC-Based DG Units in an Unbalanced
    • Authors: Noel Richard Merritt;Chandan Chakraborty;Prabodh Bajpai;
      Pages: 1127 - 1139
      Abstract: This paper presents the positive-sequence, negative-sequence, and zero-sequence voltage and current control schemes in the dq frame for the voltage-source converter (VSC)-based distributed generation (DG) units in order to compensate for voltage unbalance in a microgrid. The objective of these schemes is to control the positive-, negative-, and zero-sequence components (separately and independently) of the voltage at the point of common coupling and the VSC currents to their respective reference commands. Dynamically varying limits have been proposed for the positive- and negative-sequence references for the current control schemes in order to protect the VSC from overloading (under unbalanced conditions) and unsymmetrical faults. The active power control, frequency control, and the reactive power-voltage droop control schemes decide the references of the positive-sequence voltage control scheme in order to fulfill the objective of using the same control schemes for the grid-connected and the islanded modes of operation of the microgrid, thereby eliminating the need for islanding detection. The performance of the various control schemes employed for controlling the VSC-based DG unit has been tested on two identical VSC-based DG units feeding power to the IEEE 34 node distribution network implemented in PSCAD/EMTDC.
      PubDate: July 2017
      Issue No: Vol. 8, No. 3 (2017)
  • Coordinated Control Strategy of a Battery Energy Storage System to Support
    • Authors: Jin Tan;Yingchen Zhang;
      Pages: 1140 - 1153
      Abstract: With increasing penetrations of wind generation on electric grids, wind power plants (WPPs) are encouraged to provide frequency ancillary services (FAS); however, it is a challenge to ensure that variable wind generation can reliably provide these ancillary services. This paper proposes using a battery energy storage system (BESS) to ensure the WPPs' commitment to FAS. This method also focuses on reducing the BESS's size and extending its lifetime. In this paper, a state-machine-based coordinated control strategy is developed to utilize a BESS to support the obliged FAS of a WPP (including both primary and secondary frequency control). This method takes into account the operational constraints of the WPP (e.g., real-time reserve) and the BESS (e.g., state of charge [SOC], charge and discharge rate) to provide reliable FAS. Meanwhile, an adaptive SOC-feedback control is designed to maintain SOC at the optimal value as much as possible, and, thus, reduce the size and extend the lifetime of the BESS. The effectiveness of the control strategy is validated with an innovative multi-area interconnected power system simulation platform that can mimic realistic power systems operation and control by simulating real-time economic dispatch, regulating reserve scheduling, multi-area automatic generation control, and generators' dynamic response.
      PubDate: July 2017
      Issue No: Vol. 8, No. 3 (2017)
  • Harmonic Domain Modeling of PV System for the Assessment of Grid
           Integration Impact
    • Authors: Onyema S. Nduka;Bikash C. Pal;
      Pages: 1154 - 1165
      Abstract: In this paper, a comprehensive harmonic domain reference frame model of a voltage source converter grid interactive photovoltaic (PV) system is presented. The model is useful for assessing the harmonic coupling between the PV system and the network. Different components of the PV system such as inverter, LCL filter, and interconnecting transformer have been incorporated into the model. Using this model, harmonic currents from the PV system connected to both distorted and undistorted networks have been quantified. Also, the model has been deployed in investigating resonance occurrence in a medium-voltage distribution network, where the results provide interesting technical insight and understanding.
      PubDate: July 2017
      Issue No: Vol. 8, No. 3 (2017)
  • Coordinated Optimal Dispatch of Energy Storage in a Network of
           Grid-Connected Microgrids
    • Authors: Mohsen Rafiee Sandgani;Shahin Sirouspour;
      Pages: 1166 - 1176
      Abstract: A method is proposed for coordinated optimal dispatch of storage units in a group of grid-connected microgrids with storage and renewable energy assets to minimize the electricity costs. The method allows the microgrids to share these resources and collectively interact with the grid as one customer. A multiobjective optimization problem is formulated to obtain optimal storage charge/discharge activities using a forecast of the microgrids net electricity demands within a rolling horizon control framework. The solution to this problem also produces a virtual decomposition of the microgrids net power into local and grid components for the purpose of computing their share of electricity cost. The multiple-objective optimization is converted to a single-objective optimization by adding up the costs of the individual microgrids. An equivalent linear program free of binary/integer variables is derived from the original nonlinear optimization model, which can be effectively solved using existing solvers. Results of numerical simulations with real demand and renewable generation data are presented. They demonstrate that the coordinated optimal dispatch of the energy storage devices with the possibility of local energy transactions can significantly reduce the microgrids electricity costs compared to the cases in which they interact with the utility grid on an individual basis.
      PubDate: July 2017
      Issue No: Vol. 8, No. 3 (2017)
  • Data-Driven Statistical Analysis and Diagnosis of Networked Battery
    • Authors: Le Yi Wang;Wen Chen;Feng Lin;George Yin;
      Pages: 1177 - 1186
      Abstract: This paper analyzes system-level capacity, stored energy, and power loss, and introduces methods for their diagnosis with reliability characterization, for networked battery systems. Since system-level features of a networked battery system are functions of its member battery packs, it is of essential importance to establish rigorously this component-to-system relationship. The paper provides a method to calculate accurately diagnosis error probabilities on the system-level quantities when individual batteries' measurements are subject to measurement errors and their characterizing parameters are estimated from such measurements. These results are then used to choose diagnosis decision variables such as the thresholds for detecting faulty batteries and data sizes for estimation. Focusing on stored energy, capacity, and power loss, this paper characterizes error statistics of estimation algorithms for these quantities. Convergence of the algorithms, asymptotic probability distributions of the estimates, and diagnosis reliability analysis are performed rigorously by using stochastic differential equations, central limit theorems, and large deviations principles. Simulated case studies and experimental data are used to illustrate the methods and their usefulness.
      PubDate: July 2017
      Issue No: Vol. 8, No. 3 (2017)
  • Analysis of a Tidal Power Plant in the Estuary of Bacanga in Brazil Taking
           Into Account the Current Conditions and Constraints
    • Authors: Pedro Bezerra Leite Neto;Osvaldo R. Saavedra;Luiz Antonio de Souza Ribeiro;
      Pages: 1187 - 1194
      Abstract: There have been an increasing number of government policies and research activities aimed at the exploitation of renewable energy resources to diversify power supply and meet the growing demand for electricity. In the context of Brazil, an example of this is tidal energy, which has a significant potential and is mainly concentrated on the coast of the States of Maranhão, Pará, and Amapá. However, only a few studies have been conducted to evaluate and take advantage of this energy source. One of the works in progress involves the study of a tidal power plant installation at the dam situated at Bacanga. This paper outlines and analyzes the configuration management of a tidal power plant, which is suited to the current physical conditions of the dam and complies with operational and physical constraints. In specific terms, the study takes account the reservoir operating restrictions and available physical space for installing turbines. A recent assessment has been carried out that involves bathymetry, high-resolution photos, and 3-D scanning to evaluate the potential value of the reservoir. This allowed a complete reservoir characterization and the designing of its digital model. Annual studies of optimal operation are reported, as well as factors, such as the technical and economic benefits and drawbacks of the plant.
      PubDate: July 2017
      Issue No: Vol. 8, No. 3 (2017)
  • Probabilistic Power Flow Analysis of Power Systems Incorporating Tidal
           Current Generation
    • Authors: Zhouyang Ren;Ke Wang;Wenyuan Li;Liming Jin;Yi Dai;
      Pages: 1195 - 1203
      Abstract: A probabilistic power-flow analysis method for power systems with tidal power sources is presented in this paper. The regularity of tidal power is modeled using a k-means clustering technique and the randomness of tidal power is modeled by using a nonparametric kernel density estimation method. A stochastic sampling method is also developed to generate random samples of tidal power time series for Monte Carlo based probabilistic power-flow analysis. The influence of tidal current generation on power flows is then evaluated and quantified considering both the regularity and randomness of tidal power. The measured tidal current speed data of two different locations in Florida and Alaska states, USA, and the IEEE 57-bus standard test system are used to verify the correctness and effectiveness of the presented probabilistic power-flow analysis method.
      PubDate: July 2017
      Issue No: Vol. 8, No. 3 (2017)
  • MPPT in Dynamic Condition of Partially Shaded PV System by Using WODE
    • Authors: Nishant Kumar;Ikhlaq Hussain;Bhim Singh;Bijaya Ketan Panigrahi;
      Pages: 1204 - 1214
      Abstract: This paper introduces a humpback whale hunting behavior inspired whale optimization with differential evolution (WODE) technique-based tracking algorithm for the maximum power point tracking in the dynamic as well as the steady-state conditions of a partially shaded solar photovoltaic (PV) system. This “WODE” technique is used for quick and oscillation-free tracking of the global best peak position in a few steps. The unique advantage of this algorithm for maximum power point tracking in partially shaded condition is as, it is free from common and generalized problems of other evolutionary techniques, like longer convergence duration, a large number of search particles, steady-state oscillation, heavy computational burden, etc., which creates power loss and oscillations in output. This hybrid algorithm is tested in MATLAB simulation and verified on a developed hardware of the solar PV system, which consists of multiple peaks in voltage-power curve. Moreover, the tracking ability is compared with the state-of-the-art methods. The satisfactory steady-state and dynamic performances of the new hybrid technique under variable irradiance and temperature levels show the superiority over the state-of-the-art control methods.
      PubDate: July 2017
      Issue No: Vol. 8, No. 3 (2017)
  • Energy Demand Model for Residential Sector: A First Principles Approach
    • Authors: Rajesh Subbiah;Anamitra Pal;Eric K. Nordberg;Achla Marathe;Madhav V. Marathe;
      Pages: 1215 - 1224
      Abstract: According to the U.S. Energy Information Administration (EIA), the residential sector accounts for one-third of the country's energy consumption. This number is steadily increasing, posing a challenge to energy regulators as well as suppliers. To manage the growing demand for energy, there is a need for energy system optimization, especially on the demand side. This paper uses a first principles approach to build a high-resolution energy demand model, which can be used as a test bed by academicians as well as policy makers for performing such optimizations. This framework generates activity-based, building-level, time-dependent demand profiles. The model associates appliance usage with each household activity and calculates energy consumption based on the appliance energy rating, the duration of the energy consuming activity, and the type of activity performed by each household member. It also accounts for shared activities among household members to avoid double counting. Additionally, passive energy consumptions such as space heating/cooling, lighting, etc., are measured. Finally, validation of the results obtained by this model against real-world data for Virginia is carried out. The results indicate that the modeling framework is robust and can be extended to other parts of the U.S. and beyond.
      PubDate: July 2017
      Issue No: Vol. 8, No. 3 (2017)
  • Dispatch Model of Combined Heat and Power Plant Considering Heat Transfer
    • Authors: Yuanhang Dai;Lei Chen;Yong Min;Qun Chen;Kang Hu;Junhong Hao;Yiwei Zhang;Fei Xu;
      Pages: 1225 - 1236
      Abstract: Due to the coupling of its heat and power output, combined heat and power (CHP) has limited flexibility, which is one of the main reasons for variable renewable energy source (RES) curtailment problem in Northern China. Almost all the existing studies have modelled the CHP's output characteristics as a feasible operation region of electric power and heat power. However, only the extraction steam of a CHP unit that used for district heating can be controlled directly, without considering the extraction steam's heat transfer process, the actual heat power output cannot be precisely decided. Thus this paper proposes a detailed CHP dispatch model based on the principles of heat transfer. A three-stage heat transfer model of the extraction steam is used to describe the heating process. Then, a joint dispatch model concerning CHP units, conventional thermal power units, and RESs is given. Finally, the impacts of different factors on the extraction steam's heat transfer process and its influence for RES accommodation are analyzed. Results show that considering heat transfer process is essential in modelling the CHP plant that used for district heating, especially when the CHP plant is working at a status that deviates from the rated one significantly.
      PubDate: July 2017
      Issue No: Vol. 8, No. 3 (2017)
  • Security-Constrained Unit Commitment With Flexible Uncertainty Set for
           Variable Wind Power
    • Authors: Chengcheng Shao;Xifan Wang;Mohammad Shahidehpour;Xiuli Wang;Biyang Wang;
      Pages: 1237 - 1246
      Abstract: Power system operation has recently witnessed major challenges, which are often due to large-scale integrations of wind power generation. In this paper, a two-stage robust security-constrained unit commitment (SCUC) model is proposed for managing the wind power uncertainty in the hourly scheduling of power system generation. Different from previous studies on robust SCUC, which considered a predefined uncertainty set, the proposed method applies a flexible uncertainty set for managing the variable wind power generation. The proposed method seeks a feasible and economic dispatch in the flexible uncertainty set, takes into account wind spillage and load curtailment risks, and makes a tradeoff between the optimal wind power absorption and the economic grid operation. Several case studies are applied to the proposed method and the corresponding solutions are analyzed in the paper. The impacts of major factors, including flexible generation resources and power transmission capacity, on the proposed solution are also discussed. The numerical results demonstrate the merits of the proposed method for managing large variations in the hourly wind power generation and lowering the power system operation cost in uncertain conditions.
      PubDate: July 2017
      Issue No: Vol. 8, No. 3 (2017)
  • Fatigue Load Sensitivity-Based Optimal Active Power Dispatch For Wind
    • Authors: Haoran Zhao;Qiuwei Wu;Shaojun Huang;Mohammad Shahidehpour;Qinglai Guo;Hongbin Sun;
      Pages: 1247 - 1259
      Abstract: This paper proposes an optimal active power dispatch algorithm for wind farms based on wind turbine (WT) load sensitivity. The control objectives include tracking power references from the system operator and minimizing fatigue loads experienced by WTs. The sensitivity of WT fatigue loads to power references is defined which simplifies the formulation of the optimal power dispatch problem. Since the sensitivity value is calculated at the local WT controller, the computation burden of the central wind farm controller is largely reduced. Moreover, explicit analytical equations of the fatigue load sensitivity are derived, which significantly improves the computation efficiency of the local WT controller. The proposed algorithm can be implemented in different active power control schemes. Case studies were conducted with a wind farm under balance control for both low and high wind conditions. By comparing the rainflow cycles and damage equivalent load (DEL), the efficacy of the proposed algorithm is verified.
      PubDate: July 2017
      Issue No: Vol. 8, No. 3 (2017)
  • Day-Ahead Self-Scheduling of a Transmission-Constrained GenCo With
           Variable Generation Units Using the Incomplete Market Information
    • Authors: Yahya Kabiri Renani;Mehdi Ehsan;Mohammad Shahidehpour;
      Pages: 1260 - 1268
      Abstract: In this paper, a self-generation scheduling method for a power generation company (GenCo) with renewable generation units is presented. In the proposed method, locational market prices (LMPs) are calculated using the incomplete information on competing market participants by simulating the ISO's market clearing program and considering the effect of physical limitations of transmission lines. The errors associated with forecasted LMP and renewable production are modeled in the GenCo's generation scheduling using a robust optimization approach. The scheduling problem is modeled as a mixed-integer linear programming which is solved by a CPLEX solver in GAMS. An eight-bus system is employed to illustrate the applications of the proposed method. The numerical results show the efficiency of proposed method to reduce the GenCo's financial risks pertaining to uncertain parameters in a competitive electricity market.
      PubDate: July 2017
      Issue No: Vol. 8, No. 3 (2017)
  • Power Reserves Control for PV Systems With Real-Time MPP Estimation via
           Curve Fitting
    • Authors: Efstratios I. Batzelis;Georgios E. Kampitsis;Stavros A. Papathanassiou;
      Pages: 1269 - 1280
      Abstract: In order for a photovoltaic (PV) system to provide a full range of ancillary services to the gird, including frequency response, it has to maintain active power reserves. In this paper, a new control scheme for the dc/dc converter of a two-stage PV system is introduced, which permits operation at a reduced power level, estimating the available power (maximum power point-MPP) at the same time. This control scheme is capable of regulating the output power to any given reference, from near-zero to 100% of the available power. The proposed MPP estimation algorithm applies curve fitting on voltage and current measurements obtained during operation to determine the MPP in real time. This is the first method in the literature to use the nonsimplified single-diode model for the determination of the MPP and the five model parameters while operating at a curtailed power level. The developed estimation technique exhibits very good accuracy and robustness in the presence of noise and rapidly changing environmental conditions. The effectiveness of the control scheme is validated through simulation and experimental tests using a 2-kW PV array and a dc/dc converter prototype at constant and varying irradiance conditions.
      PubDate: July 2017
      Issue No: Vol. 8, No. 3 (2017)
  • Non-Homogeneous Markov Wind Speed Time Series Model Considering Daily and
           Seasonal Variation Characteristics
    • Authors: Kaigui Xie;Qinglong Liao;Heng-Ming Tai;Bo Hu;
      Pages: 1281 - 1290
      Abstract: Wind speed model lays the foundation of wind power simulation and is crucial to the analysis of wind power integrated into power systems. This paper proposes a non-homogeneous Markov chain (NHMC) wind speed model that takes the daily and seasonal characteristics of wind speed variation into account. An optimal partition method is adopted to divide the wind speed time series into several segments affected by seasonal changes. A seasonal index is introduced before modeling to reduce the impact of seasonal variation. A time-related variable is also introduced to describe the daily periodic variation of wind speed. Evaluation on the probability distribution, autocorrelation function, and power spectral density of NHMC model and commonly used wind speed models is conducted. Moreover, the number of NHMC states on model performance is investigated. Simulation results demonstrate that the proposed approach offers excellent fitness on overall statistical properties of the wind speed time series.
      PubDate: July 2017
      Issue No: Vol. 8, No. 3 (2017)
  • Probabilistic Optimal PV Capacity Planning for Wind Farm Expansion Based
           on NASA Data
    • Authors: Yongji Cao;Yi Zhang;Hengxu Zhang;Xiaohan Shi;Vladimir Terzija;
      Pages: 1291 - 1300
      Abstract: Considering the complementary characteristics of wind and solar energy, expanding an existing wind farm with photovoltaic panels can significantly smooth fluctuation of output power and improve operation economy. This paper proposes a two-stage approach to optimize the wind farm expansion. Based on the National Aeronautics and Space Administration data, modified meteorological models are developed considering the correlation between wind speed and solar irradiation. Taking into account fluctuation of output power, utilization of electrical equipment, and losses of renewable energy, a multi-objective optimization model is established. Two scenarios with different transformer ratings are analyzed to determine whether to expand electrical equipment. The Monte Carlo simulation is utilized to generate meteorological data in the first stage. The Pareto optimal solution set is searched by the multi-objective particle swarm optimization algorithm to determine the final solution in the second stage. A case study was conducted to validate the proposed approach.
      PubDate: July 2017
      Issue No: Vol. 8, No. 3 (2017)
  • Power System Electromechanical Oscillation Modes as Affected by Dynamic
           Interactions From Grid-Connected PMSGs for Wind Power Generation
    • Authors: Wenjuan Du;Xiao Chen;H. F. Wang;
      Pages: 1301 - 1312
      Abstract: Dynamic interactions between a grid-connected permanent magnet synchronous generator (PMSG) and power system are normally weak. This paper reports a special condition of modal resonance, under which the grid-connected PMSG may dynamically interact with power system strongly to affect power system electromechanical oscillation modes (EOMs). The special condition of modal resonance reported in this paper is that an open-loop converter oscillation mode (COM) of PMSG is close to an open-loop EOM of a power system on the complex plane. Damping torque analysis is carried out to explain why strong dynamic interactions between PMSG and power system may occur under the condition of modal resonance. Results of theoretical analysis in this paper indicate that occurrence of modal resonance may possibly cause the damping of either closed-loop COM or EOM to decrease such that power system small-signal angular stability is affected negatively by grid connection of PMSG. Responsible COMs for modal resonance are found to be related with active/reactive power control systems of a grid-side converter of PMSG. In the paper, an example multimachine power system with PMSGs is presented to demonstrate and validate analysis and conclusions made.
      PubDate: July 2017
      Issue No: Vol. 8, No. 3 (2017)
  • Maximum Power Point Tracking in Grid Connected Wind Plant by Using
           Intelligent Controller and Switched Reluctance Generator
    • Authors: Ehsan Rahmanian;Hasan Akbari;G. Hossein Sheisi;
      Pages: 1313 - 1320
      Abstract: This paper presents intelligent controllers as a maximum power point tracking system for a switched reluctance generator (SRG) driven by a variable speed wind turbine to attain the maximum power. The intelligent controller systems are artificial neural network (ANN) controller and fuzzy logic (FL) controller. Both controllers manipulate the wind turbine rotational speed by changing turn-off angle of the SRG. The turn on angle is fixed. The wind plant is connected to the grid through a DC-AC inverter system and two step up power transformers. The systems are simulated in MATLAB/ Simulink environment. The results show that the ANN controller is more accurate and efficient than the FL controller.
      PubDate: July 2017
      Issue No: Vol. 8, No. 3 (2017)
  • An Ultrafast Maximum Power Point Tracking Technique for Optimal Battery
    • Authors: Ala A. Hussein;Abbas A. Fardoun;Samantha S. Stephen;
      Pages: 1321 - 1329
      Abstract: In this paper, a new method is proposed for allocating and tracking the optimal charging frequency for sinusoidal chargers. The proposed method is based on tracking the maximum power point of the charging power by autovarying the frequency adaptively in order to get a unity power factor at the battery terminals. The proposed method has a superior performance in terms of convergence speed, ease of implementation, and applicability to different battery types. Details on the proposed method followed by simulation and experimental verification using different types of commercial batteries are presented.
      PubDate: July 2017
      Issue No: Vol. 8, No. 3 (2017)
  • Coordinated Control Strategy of Battery Energy Storage System and PMSG-WTG
           to Enhance System Frequency Regulation Capability
    • Authors: Ziping Wu;David Wenzhong Gao;Huaguang Zhang;Shijie Yan;Xiao Wang;
      Pages: 1330 - 1343
      Abstract: A novel inertial control method based on the torque limit control (TLC) is proposed in this study for the purpose of maximizing the temporary inertial response of permanent magnet synchronous generator-wind turbine generator (PMSG-WTG) over a wide range of variable wind speed conditions. To eliminate the secondary frequency drop issue during the rotor speed restoration, a small-scale battery energy storage system (BESS) is utilized by adopting the coordinated control strategy between BESS and PMSG-WTG. For the sake of minimizing the excessive use of BESS energy, this control strategy can smoothly discontinue the participation of BESS once the system frequency restores to the specified value. The simulation results conclude that the overall system frequency regulation performance can be significantly improved through such coordination control of BESS, PMSG-WTG, and conventional generators for the enhanced inertial response under different wind power penetration levels as well as variable wind speed conditions. Furthermore, the potential impact of TLC on the mechanical structures of wind turbine throughout the inertial response is investigated by using the CART2-PMSG integrated model.
      PubDate: July 2017
      Issue No: Vol. 8, No. 3 (2017)
  • Enhancing Low-Throttle-Operation Robustness of ICE-Based APU by
           Supercapacitor-Realized Virtual Inertia
    • Authors: Gal Geula;Svetlana Bronshtein;Moshe Averbukh;Alon Kuperman;
      Pages: 1344 - 1346
      Abstract: Low throttle operation of internal combustion engine-based auxiliary power units is desirable under light load to decrease specific fuel consumption. Unfortunately, sudden load increase may lead to voltage collapse and consequent stability lost due to limited total inertia and slow prime mover dynamics. This letter demonstrates that connecting a supercapacitor across auxiliary power unit output terminals is equivalent to increasing total inertia and may enhance low throttle operational robustness. Proposed findings are validated by experimental results.
      PubDate: July 2017
      Issue No: Vol. 8, No. 3 (2017)
  • The Power of Information
    • Pages: 1347 - 1347
      Abstract: Advertisement, IEEE.
      PubDate: July 2017
      Issue No: Vol. 8, No. 3 (2017)
  • Introducing the IEEE PES Resource Center
    • Pages: 1348 - 1348
      Abstract: Advertisement, IEEE.
      PubDate: July 2017
      Issue No: Vol. 8, No. 3 (2017)
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