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Actuators     Open Access  
Advances in Electrical Engineering     Open Access   (Followers: 3)
Advances in Microelectronic Engineering     Open Access   (Followers: 2)
Advances in Signal Processing     Open Access   (Followers: 1)
American Journal of Electrical and Electronic Engineering     Open Access   (Followers: 11)
American Journal of Sensor Technology     Open Access   (Followers: 1)
APSIPA Transactions on Signal and Information Processing     Open Access   (Followers: 6)
Archives of Control Sciences     Full-text available via subscription   (Followers: 2)
Archives of Electrical Engineering     Open Access   (Followers: 9)
Atom Indonesia     Open Access  
Bulletin of Electrical Engineering and Informatics     Open Access   (Followers: 9)
Circuits, Systems, and Signal Processing     Hybrid Journal   (Followers: 8)
Computers & Electrical Engineering     Hybrid Journal   (Followers: 8)
Current Trends in Signal Processing     Full-text available via subscription   (Followers: 2)
Electric Power Components and Systems     Hybrid Journal   (Followers: 7)
Electric Power Systems Research     Partially Free   (Followers: 12)
Electrical and Electronic Engineering     Open Access   (Followers: 10)
Electrical and Power Engineering Frontier     Open Access   (Followers: 9)
Electrical Engineering     Hybrid Journal   (Followers: 14)
Electrical Engineering and Automation     Open Access   (Followers: 2)
Electrical Engineering in Japan     Hybrid Journal   (Followers: 7)
Electrical, Control and Communication Engineering     Open Access   (Followers: 7)
Emerging and Selected Topics in Circuits and Systems     Hybrid Journal   (Followers: 4)
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: 2)
Frontiers of Electrical and Electronic Engineering     Hybrid Journal   (Followers: 6)
IEA Electricity Information     Full-text available via subscription   (Followers: 5)
IEEE Access     Open Access   (Followers: 5)
IEEE Electrical Insulation Magazine     Full-text available via subscription   (Followers: 8)
IEEE Signal Processing Magazine     Full-text available via subscription   (Followers: 36)
IEEE Transactions on Control of Network Systems     Hybrid Journal  
IEEE Transactions on Dielectrics and Electrical Insulation     Hybrid Journal   (Followers: 5)
IEEJ Transactions on Electrical and Electronic Engineering     Hybrid Journal   (Followers: 10)
IET Control Theory & Applications     Hybrid Journal   (Followers: 11)
IET Electric Power Applications     Hybrid Journal   (Followers: 9)
IET Electrical Systems in Transportation     Hybrid Journal   (Followers: 6)
IETE Journal of Education     Open Access   (Followers: 2)
Ingeniería Electrónica, Automática y Comunicaciones     Open Access  
Integrated Ferroelectrics: An International Journal     Hybrid Journal   (Followers: 1)
International Journal of Advanced Electronics and Communication Systems     Open Access   (Followers: 5)
International Journal of Advances in Telecommunications, Electrotechnics, Signals and Systems     Open Access   (Followers: 3)
International Journal of Electrical and Computer Engineering     Open Access   (Followers: 9)
International Journal of Electrical Engineering Education     Full-text available via subscription   (Followers: 6)
International Journal of Electrical Power & Energy Systems     Open Access   (Followers: 10)
International Journal of Emerging Electric Power Systems     Hybrid Journal   (Followers: 5)
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 on Communication     Full-text available via subscription   (Followers: 9)
International Journal on Control System and Instrumentation     Full-text available via subscription   (Followers: 10)
International Journal on Electrical and Power Engineering     Full-text available via subscription   (Followers: 11)
International Journal on Signal and Image Processing     Full-text available via subscription   (Followers: 4)
International Transaction of Electrical and Computer Engineers System     Open Access  
International Transactions on Electrical Energy Systems     Hybrid Journal   (Followers: 7)
J3eA     Open Access   (Followers: 2)
Journal of Control, Automation and Electrical Systems     Hybrid Journal   (Followers: 5)
Journal of Electrical and Computer Engineering     Open Access   (Followers: 7)
Journal of Electrical and Computer Engineering Innovations     Open Access   (Followers: 2)
Journal of Electrical and Electronics Engineering Research     Open Access   (Followers: 4)
Journal of Electrical Bioimpedance     Full-text available via subscription   (Followers: 2)
Journal of Electrical Engineering     Open Access   (Followers: 7)
Journal of Electrical Engineering & Electronic Technology     Hybrid Journal   (Followers: 2)
Journal of Electrical Systems and Information Technology     Open Access  
Journal of Field Robotics     Hybrid Journal   (Followers: 3)
Journal of Micro-Bio Robotics     Hybrid Journal   (Followers: 1)
Journal of Microwaves, Optoelectronics and Electromagnetic Applications     Open Access   (Followers: 7)
Journal of Power Technologies     Open Access   (Followers: 2)
Journal of the Society for Information Display     Hybrid Journal   (Followers: 1)
Journal of Zhejiang University SCIENCE C     Hybrid Journal  
Jurnal Infotel     Open Access  
Majlesi Journal of Electrical Engineering     Open Access  
Micro and Nano Systems Letters     Open Access   (Followers: 4)
Nanotechnology Development     Open Access   (Followers: 3)
Oil, Gas, Coal and Electricity - Quarterly Statistics - Electricite, charbon, gaz et petrole - Statistiques trimestrielles     Full-text available via subscription   (Followers: 8)
Photovoltaics, IEEE Journal of     Hybrid Journal   (Followers: 7)
Recent Patents on Electrical & Electronic Engineering     Full-text available via subscription   (Followers: 2)
Recent Patents on Telecommunications     Full-text available via subscription   (Followers: 1)
Research & Reviews : Journal of Embedded System & Applications     Full-text available via subscription   (Followers: 1)
Russian Electrical Engineering     Hybrid Journal   (Followers: 4)
Scientific Journal of Electrical Engineering     Open Access   (Followers: 5)
SID Symposium Digest of Technical Papers     Hybrid Journal   (Followers: 1)
Sustainable Energy, Grids and Networks     Hybrid Journal  
Sustainable Energy, IEEE Transactions on     Hybrid Journal   (Followers: 8)
Synthesis Lectures on Electrical Engineering     Full-text available via subscription   (Followers: 1)
Telematique     Open Access  
TELKOMNIKA : Indonesian Journal of Electrical Engineering     Open Access   (Followers: 9)
Trends in Electrical Engineering     Full-text available via subscription   (Followers: 2)
Turkish Journal of Electrical Engineering and Computer Science     Open Access   (Followers: 1)
Universal Journal of Electrical and Electronic Engineering     Open Access  
Wireless Engineering and Technology     Open Access   (Followers: 3)
Електротехніка і Електромеханіка     Open Access  
Journal Cover   Sustainable Energy, IEEE Transactions on
  [SJR: 2.826]   [H-I: 24]   [8 followers]  Follow
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 1949-3029
   Published by Institute of Electrical and Electronics Engineers (IEEE) Homepage  [176 journals]
  • IEEE Transactions on Sustainable Energy society information
    • Abstract: Provides a listing of current staff, committee members and society officers.
      PubDate: April 2015
      Issue No: Vol. 6, No. 2 (2015)
  • IEEE Power Engineering Society information for authors
    • Abstract: Presents information for authors publishing in this journal.
      PubDate: April 2015
      Issue No: Vol. 6, No. 2 (2015)
  • Table of Contents
    • Pages: 293
      Abstract: Presents the table of contents for this issue of the publication.
      PubDate: April 2015
      Issue No: Vol. 6, No. 2 (2015)
  • IEEE Transactions on Sustainable Energy
    • Abstract: Provides a listing of the editorial board, current staff, committee members and society officers.
      PubDate: April 2015
      Issue No: Vol. 6, No. 2 (2015)
  • Numerical Optimal Control of Wave Energy Converters
    • Authors: Bacelli; G.;Ringwood, J.V.;
      Pages: 294 - 302
      Abstract: Energy maximizing control for wave energy converters (WECs) is a nonstandard optimal control problem. While the constrained optimal control problem for WECs has been addressed by model-predictive control strategies, such strategies need to employ cost function modifications due to convexity problems and the algorithms are computationally complex, making real-time implementation difficult. The recently developed family of direct transcription methods offer a promising alternative, since they are computationally efficient and a convex problem results. Moreover, constraints on both the device displacement and velocity, and power take off force, are easily incorporated. Both single-body and multibody device models can be used, as well as arrays of single-body or multibody devices.
      PubDate: April 2015
      Issue No: Vol. 6, No. 2 (2015)
  • A Parallel Capacitor Control Strategy for Enhanced FRT Capability of DFIG
    • Authors: Huchel; L.;El Moursi, M.S.;Zeineldin, H.H.;
      Pages: 303 - 312
      Abstract: This paper presents a novel dc-link scheme for enhancing the fault ride-through (FRT) capability of doubly fed induction generator-based wind turbine (DFIG-WT). The proposed system consists of parallel capacitors with a dedicated control strategy designed to provide means for power evacuation during grid fault conditions. This technically simple and cost-effective scheme was developed considering transmission line autoreclosing which may cause multiple fault inceptions. Simulation studies were carried out to compare the performance of the introduced solution with a DFIG-WT, equipped with the dc chopper and crowbar. The simulation results demonstrate the enhanced performance of the proposed approach in maintaining the dc-link voltage, transient rotor voltages, and currents within the permissible operating range during a bolted three-phase-to-ground fault. The proposed schemes were also tested in response to asymmetrical grid faults, and the enhancement in transient response has been verified. An experimental setup was developed to emulate the behavior of the dc-link circuit during fault conditions. These experimental results demonstrate the effectiveness of the switching parallel capacitors in preventing dc-link overvoltage during imbalance power operation. The discharging capacitor circuit highlighted the capability of tackling the multiple fault inception problems while adhering to grid code requirements.
      PubDate: April 2015
      Issue No: Vol. 6, No. 2 (2015)
  • Demand Side Storage to Increase Hydroelectric Generation Efficiency
    • Authors: Moghadam; M.F.;Metcalfe, M.;Dunford, W.G.;Vaahedi, E.;
      Pages: 313 - 324
      Abstract: In this paper, a new generation control strategy is proposed based on combined use of different resources including large hydroelectric power plants and directly controlled industrial responsive loads. Water pumping in water storage systems is modeled as a virtual power plant (VPP) in transmission system. The balance model is in the economic dispatch (ED) time frame and loads are scheduled to be dispatched optimally along with the swing hydroelectric plant, which realizes load-following and frequency regulation. The model is implemented on the IEEE 24 bus reliability test system with hydroelectric generation units. Real-field data of responsive loads are used and the results show the value of flexibility of responsive loads in increasing generation efficiency of hydroelectric power plants operated in swing mode.
      PubDate: April 2015
      Issue No: Vol. 6, No. 2 (2015)
  • Aggregation and Bidirectional Charging Power Control of Plug-in Hybrid
           Electric Vehicles: Generation System Adequacy Analysis
    • Authors: Zhe Liu;Dan Wang;Hongjie Jia;Djilali; N.;Weixin Zhang;
      Pages: 325 - 335
      Abstract: With increasing penetration of plug-in hybrid electric vehicles (PHEVs), it is necessary to introduce a two-way interactive mechanism between PHEVs and the power system to improve system reliability and satisfy the PHEV charging requirements. To address these requirements, a bidirectional charging power control method, based on the time series model of PHEV charging, is developed. The control strategy ensures that PHEVs achieve full-charge before the users' desired disconnecting time, and allows the spare time during users desired charging horizons to be used to manage PHEV charging power and to respond to the generation capacity shortage signal. Grid-to-vehicle (G2V) and vehicle-to-grid (V2G) control strategies are defined to determine whether PHEVs draw power from the grid or inject power to the grid. Generation system adequacy and PHEV charging behavior are analyzed for various scenarios under this interactive mechanism, and the costs and benefits to vehicle users and utilities are analyzed based on several new generation system adequacy indices. The simulation results illustrate how charging power control can effectively improve generation system adequacy, particularly for higher PHEV penetration and when users are incentivized to extend charging horizons.
      PubDate: April 2015
      Issue No: Vol. 6, No. 2 (2015)
  • Model Predictive Control of a Nonlinear 2-Body Point Absorber Wave Energy
           Converter With Estimated State Feedback
    • Authors: Amann; K.U.;Magana, M.E.;Sawodny, O.;
      Pages: 336 - 345
      Abstract: Ocean wave energy has the potential to significantly contribute to sustainable power generation in coastal regions. Much of the research effort has gone into developing time domain state space models of point absorber wave energy converters (WECs) and subsequently into model-based optimal control to efficiently harvest the maximum possible amount of energy. The resulting controllers require knowledge of the states of the WEC in order to achieve the design goals. The purpose of this paper is to design and apply an extended Kalman filter-based estimation algorithm to a nonlinear two-body WEC model and to evaluate its performance in conjunction with a model predictive controller (MPC), which maximizes energy yield while satisfying operational constraints.
      PubDate: April 2015
      Issue No: Vol. 6, No. 2 (2015)
  • Preemptive Demand Response Management for Buildings
    • Authors: Sivaneasan; B.;Nandha Kumar, K.;Tan, K.T.;So, P.L.;
      Pages: 346 - 356
      Abstract: A building energy management system (BEMS), which forms an integral part of a smart grid, enables building operators to monitor, manage, and control the energy utilized in their buildings, thus reducing the demand and consumption of energy. Building operators are responsible for the day-to-day maintenance and operation of their buildings' heating, cooling, mechanical, and electrical systems. This paper proposes an intelligent preemptive demand response management (DRM) using the BEMS to ensure contracted capacity or demand limit (CC/DL) is not exceeded and at the same time reduce energy consumption in buildings. In this paper, dynamic electric vehicle (EV) charge scheduling, speed control of air conditioning (AC) system's variable speed drive (VSD), and priority-based load shedding are considered in the DRM program. The performance of the proposed DRM program to keep the building power demand within the CC/DL and reduce the energy consumption is tested and analyzed using the BEMS.
      PubDate: April 2015
      Issue No: Vol. 6, No. 2 (2015)
  • Adjustable Robust Real-Time Power Dispatch With Large-Scale Wind Power
    • Authors: Zhigang Li;Wenchuan Wu;Boming Zhang;Bin Wang;
      Pages: 357 - 368
      Abstract: In this paper, we propose a robust real-time wind power dispatch framework for coordinating wind farms, automatic generation control (AGC) units, and nonAGC units, which enables wind farms to operate flexibly using maximum power-point tracking strategies. Robust real-time dispatch is formulated as an adjustable robust optimization model incorporating an affinely adjustable controlling strategy compatible with AGC systems. The proposed model can be equivalently transformed to a nonlinear programming problem with linear constraints via duality. The proposed model can also be approximately reduced to a quadratic programming with the objective function simplified. Monte Carlo simulations are carried out to compare the performance of the proposed method against the conventional real-time dispatch scheme. The results show the proposed scheme is robust and reliable.
      PubDate: April 2015
      Issue No: Vol. 6, No. 2 (2015)
  • Microinverter Curtailment Strategy for Increasing Photovoltaic Penetration
           in Low-Voltage Networks
    • Authors: Gagrica; O.;Nguyen, P.H.;Kling, W.L.;Uhl, T.;
      Pages: 369 - 379
      Abstract: Transition toward smart distribution networks with high penetration of photovoltaics (PVs) will involve incidental generation curtailment as an alternative to grid reinforcements. Microinverters are taking over popularity of string inverters in residential and some commercial areas mainly due to increased energy harvest. This paper demonstrates how microinverters with a modified overvoltage protection scheme could provide a reliable curtailment solution and accommodate additional PV capacity. Two wide-area curtailment schemes were proposed for a typical Dutch residential feeder with densely clustered PV. First, a single worst-case scenario was used to demonstrate the capabilities of the proposed curtailment schemes: the distribution network operators can optimize between various priorities such as total feeder output, economic equality between connected parties, voltage levels, voltage unbalance, and curtailment execution time. Second, a yearly comparison was made against conventional overvoltage protection and the results show 62%-100% reduction in overvoltage losses.
      PubDate: April 2015
      Issue No: Vol. 6, No. 2 (2015)
  • A Temperature-Dependent Study of Sealed Lead-Acid Batteries Using Physical
           Equivalent Circuit Modeling With Impedance Spectra Derived High
           Current/Power Correction
    • Authors: Greenleaf; M.;Dalchand, O.;Hui Li;Zheng, J.P.;
      Pages: 380 - 387
      Abstract: A lead-acid battery model was developed for use in characterizing lead-acid battery performance for renewable energy power generation and load balancing. This model includes the effect of temperature, current, and state of charge (SOC). The model was tested against experimental results for constant power discharge. This model also shows a strong link between the applied dc current and the effective impedance of the cell.
      PubDate: April 2015
      Issue No: Vol. 6, No. 2 (2015)
  • SSR Damping Controller Design and Optimal Placement in Rotor-Side and
           Grid-Side Converters of Series-Compensated DFIG-Based Wind Farm
    • Authors: Mohammadpour; H.A.;Santi, E.;
      Pages: 388 - 399
      Abstract: This paper deals with subsynchronous resonance (SSR) phenomena in a capacitive series-compensated DFIG-based wind farm. Using both modal analysis and time-domain simulation, it is shown that the DFIG wind farm is potentially unstable due to the SSR mode. In order to damp the SSR, the rotor-side converter (RSC) and grid-side converter (GSC) controllers of the DFIG are utilized. The objective is to design a simple proportional SSR damping controller (SSRDC) by properly choosing an optimum input control signal (ICS) to the SSRDC block, so that the SSR mode becomes stable without decreasing or destabilizing the other system modes. Moreover, an optimum point within the RSC and GSC controllers to insert the SSRDC is identified. Three different signals are tested as potential ICSs including rotor speed, line real power, and voltage across the series capacitor, and an optimum ICS is identified using residue-based analysis and root-locus method. Moreover, two methods are discussed in order to estimate the optimum ICS, without measuring it directly. The studied power system is a math\bf{100;{\rm MW}} DFIG-based wind farm connected to a series-compensated line whose parameters are taken from the IEEE first benchmark model (FBM) for computer simulation of the SSR. MATLAB/Simulink is used as a tool for modeling and designing the SSRDC, and power system computer aided design/electromagnetic transients including dc (PSCAD/EMTDC) is used to perform time-domain simulation for design process validation.
      PubDate: April 2015
      Issue No: Vol. 6, No. 2 (2015)
  • Integrated Photovoltaic and Dynamic Voltage Restorer System Configuration
    • Authors: Rauf; A.M.;Khadkikar, V.;
      Pages: 400 - 410
      Abstract: This paper presents a new system configuration for integrating a grid-connected photovoltaic (PV) system together with a self-supported dynamic voltage restorer (DVR). The proposed system termed as a “six-port converter,” consists of nine semiconductor switches in total. The proposed configuration retains all the essential features of normal PV and DVR systems while reducing the overall switch count from twelve to nine. In addition, the dual functionality feature significantly enhances the system robustness against severe symmetrical/asymmetrical grid faults and voltage dips. A detailed study on all the possible operational modes of six-port converter is presented. An appropriate control algorithm is developed and the validity of the proposed configuration is verified through extensive simulation as well as experimental studies under different operating conditions.
      PubDate: April 2015
      Issue No: Vol. 6, No. 2 (2015)
  • Grid Harmonics Suppression Scheme for LCL-Type
           Grid-Connected Inverters Based on Output Admittance Revision
    • Authors: Xiaojie Wu;Xiaoqiang Li;Xibo Yuan;Yiwen Geng;
      Pages: 411 - 421
      Abstract: In this paper, the influence of grid harmonics on the output current of grid-connected inverters with an LCL filter is investigated by means of the output admittance. With the complex transfer model of the output admittance, the full-feedforward scheme of grid voltage is derived, which, however, is difficult to be implemented due to the derivative terms in the feedforward link. A detailed theoretical analysis is also presented to explain the compensation error introduced by the active damping and delays when the grid voltage proportional feedforward is adopted. Then a feedforward scheme based on the band-pass filter (BPF) is proposed to compensate the grid harmonics at the selected frequencies, and the parameters of the BPF are derived to revise the output admittance. It has also been found that with the commonly used phase-locked loop (PLL), an additional admittance matrix is introduced. The compensation effect will be degraded when the PLL with a high bandwidth is used for tracking grid phase accurately. Therefore, a modified PLL is proposed to revise the output admittance again, for suppressing the output current distortion arising from the grid harmonics, which propagate to control system through the PLL. Finally, the experimental results verify the effectiveness of the proposed scheme, where the current harmonics are effectively suppressed.
      PubDate: April 2015
      Issue No: Vol. 6, No. 2 (2015)
  • Wind Power Ramp Event Forecasting Using a Stochastic Scenario Generation
    • Authors: Mingjian Cui;Deping Ke;Yuanzhang Sun;Di Gan;Jie Zhang;Hodge; B.-M.;
      Pages: 422 - 433
      Abstract: Wind power ramp events (WPREs) have received increasing attention in recent years as they have the potential to impact the reliability of power grid operations. In this paper, a novel WPRE forecasting method is proposed which is able to estimate the probability distributions of three important properties of the WPREs. To do so, a neural network (NN) is first proposed to model the wind power generation (WPG) as a stochastic process so that a number of scenarios of the future WPG can be generated (or predicted). Each possible scenario of the future WPG generated in this manner contains the ramping information, and the distributions of the designated WPRE properties can be stochastically derived based on the possible scenarios. Actual wind power data from a wind power plant in the Bonneville Power Administration (BPA) were selected for testing the proposed ramp forecasting method. Results showed that the proposed method effectively forecasted the probability of ramp events.
      PubDate: April 2015
      Issue No: Vol. 6, No. 2 (2015)
  • An Improved Photovoltaic Power Forecasting Model With the Assistance of
           Aerosol Index Data
    • Authors: Jun Liu;Wanliang Fang;Xudong Zhang;Chunxiang Yang;
      Pages: 434 - 442
      Abstract: Due to the intermittency and randomness of solar photovoltaic (PV) power, it is difficult for system operators to dispatch PV power stations. In order to find a precise expectation for day-ahead PV power generation, conventional models have taken into consideration the temperature, humidity, and wind speed data for forecasting, but these predictions were always not accurate enough under extreme weather conditions. Aerosol index (AI), which indicates the particulate matter in the atmosphere, has been found to have strong linear correlation with solar radiation attenuation, and might have potential influence on the power generated by PV panels. A novel PV power forecasting model is proposed in this paper, considering AI data as an additional input parameter. Based on seasonal weather classification, the back propagation (BP) artificial neural network (ANN) approach is utilized to forecast the next 24-h PV power outputs. The estimated results of the proposed PV power forecasting model coincide well with measurement data, and the proposed model has shown the ability of improving prediction accuracy, compared with conventional methods using ANN.
      PubDate: April 2015
      Issue No: Vol. 6, No. 2 (2015)
  • Coordination of Hydro Units With Wind Power Generation Using Interval
    • Authors: Yangyang Liu;Chuanwen Jiang;Jingshuang Shen;Jiakai Hu;
      Pages: 443 - 453
      Abstract: The coordination of wind power and hydro power is an effective way for generating companies to enhance the ability of wind power dispatch and to avoid imbalance charges. However, specifying the probability distributions of random variables can be challenging for decision makers (DMs). This paper proposes a bidding strategy for wind farms and hydro stations in a generating company using interval optimization. Pessimistic preference ordering and DMs' degrees of pessimism are also adopted in the optimization to compare interval numbers. Variations in wind power, the day-ahead energy price, and the intrahour energy price are then considered and represented by interval numbers instead of probability distributions. Compared with stochastic optimization, interval optimization does not need an exact probability distribution for the random variables. Moreover, it can reduce computational complexity as well as determine and optimize profit intervals, as illustrated in the numerical example presented herein.
      PubDate: April 2015
      Issue No: Vol. 6, No. 2 (2015)
  • Conditional Range Metric for Determining Wind Power Variability of Scarce
           or Noisy Data
    • Authors: Yichuan Niu;Santoso; S.;
      Pages: 454 - 463
      Abstract: Understanding the nature and characteristics of wind power variability is critical to improving power system operations. Using a relatively large volume of measured wind power time series, the conditional range metric (CRM) has successfully been employed to quantify intra-hour wind power variability. The objective of this paper is to extend the application of the CRM-based method to sparsely sampled wind power time series. To improve the accuracy and adaptability of the CRM, a gamma distribution is proposed to model the power-deviation series without introducing the joint probability density matrix. The shape and inverse scale parameters \alpha and \beta of the gamma distribution are calculated by the maximum-likelihood estimator (MLE) at each production level. Bayesian estimators (BEs) for \alpha and \beta are then developed as a posterior joint distribution to calculate their expectations by taking the mean value of the paired sample points via a modified rejection sampling strategy. The match between the two estimation results indicates a valid assumption of the likelihood distribution and exact estimated parameters. Applying data from the National Renewable Energy Laboratory and their down-sampled subsets, the efficacy of the proposed CRM with the gamma distribution approach is compared to that of the existing CRM with a quantile model.
      PubDate: April 2015
      Issue No: Vol. 6, No. 2 (2015)
  • Performance of Medium-Voltage DC-Bus PV System Architecture Utilizing
           High-Gain DC–DC Converter
    • Authors: Hyuntae Choi;Ciobotaru; M.;Minsoo Jang;Agelidis, V.G.;
      Pages: 464 - 473
      Abstract: The number of large-scale solar photovoltaic (PV) systems continues to increase, while the size of the largest systems has already reached several hundred megawatts. This trend will challenge existing PV system architectures and will require new PV system architectures with higher power ratings and higher voltage levels at the point of common coupling (PCC). This paper reports a medium-voltage (MV) dc-bus PV system architecture based on a high-gain soft-switched interleaved boost (SSIB) dc-dc converter. The interleaved characteristic increases the flexibility of the converter, allowing for either a higher voltage and/or current rating, thus increasing the power rating of the converter. The high-gain capability of the SSIB converter allows it to be connected directly to an MV dc bus. This will facilitate direct connection of a PV system to an MV ac grid (i.e., 20 kV) using only one step-up transformer. Simulation and experimental results are presented to verify the operation of the SSIB converter and to confirm the steady-state and dynamic performance of the proposed PV system architecture.
      PubDate: April 2015
      Issue No: Vol. 6, No. 2 (2015)
  • High-Precision Forecasting Model of Solar Irradiance Based on Grid Point
           Value Data Analysis for an Efficient Photovoltaic System
    • Authors: Bin Mohd Shah; A.S.;Yokoyama, H.;Kakimoto, N.;
      Pages: 474 - 481
      Abstract: An accurate forecasting system is extremely crucial in order to simulate an optimum output level of photovoltaic (PV) power production for the next day. In this study, a relatively high-precision model of solar irradiance forecasting based on grid point value (GPV) datasets using relative humidity, precipitation, and three-level cloud covers parameterization has been conducted in Hitachi and four main cities in Japan. In the case of cloudy/rainy/snowy days, the influence of liquid water path is further introduced to the model. As a result, correlation coefficient r of 0.94, 0.91, 0.91, 0.89, and 0.92 have been obtained using 21UTC forecast version in 2012 datasets for Hitachi, Tokyo, Nagoya, Osaka, and Fukuoka, respectively. Surprisingly, although the earlier forecast version, using 9UTC datasets, was later applied to the model, there was no significant change to the r for these five locations as their values reduced by only approximately 0.01 at most. Furthermore, a similar trend has also been observed for the 2013 datasets from a comparison of 21UTC and 9UTC versions, which highly supports the fact that this model is reliable, since it still remains in a high-precision state even in the case where the earlier datasets of previous day are used.
      PubDate: April 2015
      Issue No: Vol. 6, No. 2 (2015)
  • A Grid-Connected Dual Voltage Source Inverter With Power Quality
           Improvement Features
    • Authors: Manoj Kumar; M.V.;Mishra, M.K.;Kumar, C.;
      Pages: 482 - 490
      Abstract: This paper presents a dual voltage source inverter (DVSI) scheme to enhance the power quality and reliability of the microgrid system. The proposed scheme is comprised of two inverters, which enables the microgrid to exchange power generated by the distributed energy resources (DERs) and also to compensate the local unbalanced and nonlinear load. The control algorithms are developed based on instantaneous symmetrical component theory (ISCT) to operate DVSI in grid sharing and grid injecting modes. The proposed scheme has increased reliability, lower bandwidth requirement of the main inverter, lower cost due to reduction in filter size, and better utilization of microgrid power while using reduced dc-link voltage rating for the main inverter. These features make the DVSI scheme a promising option for microgrid supplying sensitive loads. The topology and control algorithm are validated through extensive simulation and experimental results.
      PubDate: April 2015
      Issue No: Vol. 6, No. 2 (2015)
  • Stochastic Capacity Expansion Planning of Remote Microgrids With Wind
           Farms and Energy Storage
    • Authors: Hajipour; E.;Bozorg, M.;Fotuhi-Firuzabad, M.;
      Pages: 491 - 498
      Abstract: A majority of remote power systems are going to be supplied by diesel-renewable resources such as wind and photovoltaic energy in the future. However, the unpredictable nature of wind generation increases the concern about the reliable operation of these isolated microgrids. Using energy storage systems (ESSs) is recently accepted as an efficient solution to the volatility and intermittency of renewable energy sources. In this paper, a stochastic programming based on the Monte Carlo approach is introduced for optimal planning of remote systems. So far, most literatures have focused exclusively on the energy storage initial sizing. However, capacity expansion of ESS through the time span can result in significant cost saving and will be illustrated in this paper. Factors such as reliability criteria together with the investment and the operation costs are taken into account in the proposed methodology. This method utilizes practical operational constraints of ESS including efficiency and life cycle. Considering life cycle constraint reinforces the proposed method to completely investigate the difference between ESS technologies. The results of case study demonstrate that the proposed capacity expansion algorithm could lead to about 10% more profit over the traditional energy storage sizing.
      PubDate: April 2015
      Issue No: Vol. 6, No. 2 (2015)
  • Partial Shading Analysis of Multistring PV Arrays and Derivation of
           Simplified MPP Expressions
    • Authors: Psarros; G.N.;Batzelis, E.I.;Papathanassiou, S.A.;
      Pages: 499 - 508
      Abstract: In this paper, the electrical response of a partially shaded photovoltaic (PV) array, comprising several strings connected in parallel, is investigated. The PV array is simulated by employing an enhanced version of the widely used single-diode model, reformulated in an explicit manner employing the Lambert W function. The multiple maximum power points (MPPs) that appear on the P-V characteristic of the array in partial shading conditions are analyzed, in terms of their number and properties. Simplified empirical expressions are then derived to calculate the voltage, current, and power for each local MPP, at any irradiance level and temperature, using only datasheet information, in a most simple and straightforward manner, without resorting to detailed modeling and simulations. The derived formulae are validated using both simulation and experimental results.
      PubDate: April 2015
      Issue No: Vol. 6, No. 2 (2015)
  • Shuffled Frog Leaping Algorithm for Photovoltaic Model Identification
    • Authors: Hasanien; H.M.;
      Pages: 509 - 515
      Abstract: In simulation studies of photovoltaic (PV) systems with power electronic converters, the simulation results are affected by the accuracy of the PV model. The maximum power point tracking, transient and dynamic analysis of the PV systems, and operation of microgrids systems are examples of these simulation studies. The mathematical model of the PV module is a nonlinear I-V characteristic that includes several unknown parameters because of the limited information provided by the PV manufacturers. This paper presents a novel approach using the shuffled frog leaping algorithm (SFLA) to determine the unknown parameters of the single diode PV model. The validity of the proposed PV model is verified by the simulation results which are performed under different environmental conditions. The simulation results are compared with the experimental results of different PV modules such as Kyocera KC200GT and Solarex MSX-60. The effectiveness of the proposed PV model is evaluated by comparing the absolute error of the model with respect to the experimental results with that of other PV models. With the application of the SFLA technology, an accurate PV model can be achieved.
      PubDate: April 2015
      Issue No: Vol. 6, No. 2 (2015)
  • Demand Response Exchange in the Stochastic Day-Ahead Scheduling With
           Variable Renewable Generation
    • Authors: Hongyu Wu;Shahidehpour; M.;Alabdulwahab, A.;Abusorrah, A.;
      Pages: 516 - 525
      Abstract: This paper proposes a pool-based demand response exchange (DRX) model in which economic demand response (DR) is traded among DR participants as an alternative for managing the variability of renewable energy sources (RES). Load curtailment bids are provided by individual DRX participants and the DRX is cleared by maximizing the total social welfare, which is subject to supply-demand balance and individual bidders' inter-temporal operation constraints. The proposed DRX model is further integrated in the current context of the ISO's day-ahead scheduling in electricity markets. A two-step sequential market clearing framework is presented in which the ISO's stochastic day-ahead scheduling is simulated first for calculating the expected locational marginal prices (LMPs) and then, the proposed DRX is cleared successively using the expected LMPs. The simulation of the ISO's stochastic day-ahead scheduling incorporates random outages of system components and forecast errors for hourly renewable generation and loads. The decomposition-based method is employed to solve the ISO's day-ahead scheduling in the base case and scenarios. Numerical tests are performed for a 6-bus system and an IEEE 118-bus system. The results demonstrate the benefit of utilizing the DRX model for customer market participation in the ISO's day-ahead market scheduling.
      PubDate: April 2015
      Issue No: Vol. 6, No. 2 (2015)
  • Multiple Lightning Discharges in Wind Turbines Associated With Nearby
           Cloud-to-Ground Lightning
    • Authors: Candela Garolera; A.;Cummins, K.L.;Madsen, S.F.;Holboell, J.;Myers, J.D.;
      Pages: 526 - 533
      Abstract: This paper presents the analysis of five events where simultaneous lightning currents were registered in different wind turbines of a wind farm with lightning monitoring equipment installed. Measurements from current monitoring devices installed at the wind turbines and observations from auto-triggering video cameras were correlated with data from the U.S. National Lighting Detection Network. In all five events, the correlation showed that a cloud-to-ground (CG) lightning stroke with high peak current struck the ground within 10 km of the affected turbines at the time of the currents in the wind turbines. The polarity of the CG discharges was negative in two events and positive in the three remaining events, which were also accompanied by small intracloud pulses. According to the analysis of the data for each event, the simultaneous discharges at the wind turbines are most likely caused by the nearby CG strokes, involving mechanisms that vary depending on the polarity of the associated CG stroke. The analysis also suggests that the event of upward lightning from wind turbines triggered by nearby lightning activity occurs very often and therefore it should be considered carefully in the processes of assessing the lightning exposure of the wind turbines, designing the lightning protection, and defining validation tests.
      PubDate: April 2015
      Issue No: Vol. 6, No. 2 (2015)
  • A Novel Multiagent Control Scheme for Voltage Regulation in DC
           Distribution Systems
    • Authors: Hamad; A.A.;Farag, H.E.;El-Saadany, E.F.;
      Pages: 534 - 545
      Abstract: This paper proposes a novel multiagent control scheme to mitigate the voltage regulation challenges of dc distribution systems (DCDSs) with high penetration of distributed and renewable generation (DG). The proposed control scheme consists of two sequential stages. In the first stage, a distributed state estimation algorithm is implemented to estimate the voltage profile in a DCDS, thus enhancing the ac/dc converter operation to keep the system voltages within specified limits. The second stage is activated only when the ac/dc fails to regulate the system voltages. Two distributed power management control strategies are proposed in the second stage. The first is based on a distributed equal curtailment, at which all DG units responsible for the voltage violation are equally curtailed. The second strategy aims to optimize the output power in order to maximize the revenue of DG units. The formulated problem in the second strategy is classified as a convex optimization problem under global constraints. A distributed Lagrangian primal-dual subgradient (DLPDS) algorithm is proposed in order to obtain the global optimal solution of the formulated problem. Various case studies are performed to prove the effectiveness, robustness, and convergence characteristics of the proposed control schemes.
      PubDate: April 2015
      Issue No: Vol. 6, No. 2 (2015)
  • A Semi-Markov Model for Control of Energy Storage in Utility Grids and
           Microgrids With PV Generation
    • Authors: Barnes; A.K.;Balda, J.C.;Escobar-Mejia, A.;
      Pages: 546 - 556
      Abstract: Photovoltaic (PV) penetration levels in the power grid have significantly increased during the last years. However, issues such as cloud-induced intermittency in PV generation forces equipment on the electrical grid to cycle excessively, preventing PV generation from being considered as a reliable or dispatchable source of power, particularly by utilities. A semi-Markov process model is proposed to model PV power. Unlike existing models of PV power, the proposed model has a wide range of applicability across both small and large timescales. These applications include simulating PV power, short-term forecasting of PV power, design of rule-based controllers for energy storage units (ESU), and stochastic scheduling of ESU in conjunction with other resources. The model is applied to study two cases of coordinating ESU with PV generation. In the first case, the model serves to design a coordination scheme for a hybrid battery-ultracapacitor (UC) ESU where the UC serves to extend the lifetime of a lead-acid battery. In the second case, the model allows probabilistic scheduling in a standalone PV/diesel/battery-ESU microgrid. In both cases, the model improves performance in terms of either battery lifetime or fuel consumption.
      PubDate: April 2015
      Issue No: Vol. 6, No. 2 (2015)
  • A Balance-of-Plant Vanadium Redox Battery System Model
    • Authors: Xin Qiu;Crow; M.L.;Elmore, A.C.;
      Pages: 557 - 564
      Abstract: The vanadium redox flow battery (VRB) is well suited for renewable energy applications. It has many attributes, which make it an excellent choice for bulk power applications. However, as with all energy storage systems, the energy storage device must consider the balance of plant in computing performance efficiencies. This paper studies VRB use within a microgrid system from a practical perspective. A reduced order circuit model of the VRB is introduced that includes the losses from the balance of system including system and environmental controls. Experimental field data are collected to estimate the key parameters of the VRB system. The proposed models include the circulation pumps and the heating, ventilation, and air conditioning system that regulates the environment of the VRB enclosure. In this paper, the VRB model is extended to include the energy storage system environmental controls to provide a model that provides a more realistic efficiency profile.
      PubDate: April 2015
      Issue No: Vol. 6, No. 2 (2015)
  • Control of PMSG-Based Wind Turbines for System Inertial Response and Power
           Oscillation Damping
    • Authors: Yi Wang;Jianhui Meng;Xiangyu Zhang;Lie Xu;
      Pages: 565 - 574
      Abstract: This paper investigates an improved active power control method for variable speed wind turbine to enhance the inertial response and damping capability during transient events. The optimized power point tracking (OPPT) controller, which shifts the turbine operating point from the maximum power point tracking (MPPT) curve to the virtual inertia control (VIC) curves according to the frequency deviation, is proposed to release the “hidden” kinetic energy and provide dynamic frequency support to the grid. The effects of the VIC on power oscillation damping capability are theoretically evaluated. Compared to the conventional supplementary derivative regulator-based inertia control, the proposed control scheme can not only provide fast inertial response, but also increase the system damping capability during transient events. Thus, inertial response and power oscillation damping function can be obtained in a single controller by the proposed OPPT control. A prototype three-machine system containing two synchronous generators and a PMSG-based wind turbine with 31% of wind penetration is tested to validate the proposed control strategy on providing rapid inertial response and enhanced system damping.
      PubDate: April 2015
      Issue No: Vol. 6, No. 2 (2015)
  • Control-Informed Optimal Array Layout for Wave Farms
    • Authors: Garcia-Rosa; P.B.;Bacelli, G.;Ringwood, J.V.;
      Pages: 575 - 582
      Abstract: Somewhat similar to wind farms, commercial wave energy will be realized using farms of devices. However, for wave farms, both constructive and destructive interference may occur between individual devices; whereas, for wind farms, only destructive interference occurs. In order to maximize constructive interference, the layout of the wave farm must be optimized. In addition, power absorption may be improved by applying a control system technology to the farm of devices. As with many applications, there is a tendency in wave energy to separate the design of the array layout from the design of an energy maximizing control system. In this paper, we show that integrating the activities of optimal array layout design and control design are crucial if the full potential of the wave farm is to be realized. In particular, we show that a layout optimized without knowledge of the control system to be used can be inferior to the extent of recovering 40% less energy than a farm layout optimized with knowledge of the control system. This loss is significantly more than the difference in performance between a simple and a very complex control strategy.
      PubDate: April 2015
      Issue No: Vol. 6, No. 2 (2015)
  • Reducing Generation Uncertainty by Integrating CSP With Wind Power: An
           Adaptive Robust Optimization-Based Analysis
    • Authors: Runze Chen;Hongbin Sun;Qinglai Guo;Zhigang Li;Tianhu Deng;Wenchuan Wu;Boming Zhang;
      Pages: 583 - 594
      Abstract: The uncertainty of wind power generation brings problems in power system operation, such as requiring more reserves and possible frequency issues. In this paper, we propose an idea of combining concentrating solar power (CSP) plants with wind farms to reduce the overall uncertainty in the joint power output. Taking advantage of the dispatchability of CSP, the uncertainty of joint power generation is expected to decrease. Based on the operational model of CSP plants with thermal storage system, we search for the narrowest but robust bounds of the joint power output with a given uncertainty of the wind power output and solar power availability, and within operational constraints of CSP plants. The problem is formulated as an adaptive robust optimization (RO) problem, containing mixed-integer variables at the second stage. We introduce an algorithm that combines a nested column-and-constraint generation (C-CG) method and an outer approximation (OA) method to solve the problem. The case studies show that robust intervals for the joint power output can be obtained, and the obtained intervals can be significantly narrower than the original intervals of wind power.
      PubDate: April 2015
      Issue No: Vol. 6, No. 2 (2015)
  • An Improved Current Controller for Grid Connected Voltage Source Converter
           in Microgrid Applications
    • Authors: Tummuru; N.R.;Mishra, M.K.;Srinivas, S.;
      Pages: 595 - 605
      Abstract: This paper proposes an improved control scheme for grid interactive voltage source converter (VSC) feeding nonlinear and unbalanced loads connected at the point of common coupling (PCC). A gain scheduling multiresonating controller is proposed to cope with step changes in the reference power commands. The gain scheduling laws are presented under different conditions of reference and load powers. A variable window Fourier transform (VWFT) is employed to compute the average grid power under grid frequency variation and instantaneous symmetrical components theory (ISCT) is used for generation of VSC reference currents. This scheme is also used to facilitate the power flow control along with additional power quality compensation features under distorted grid conditions. The proposed control scheme provides good compensation and tracking performance under step changes in the reference power, grid frequency, and load disturbances. The effectiveness of the proposed control scheme is tested using MATLAB/Simulink simulations and is validated experimentally on a laboratory prototype.
      PubDate: April 2015
      Issue No: Vol. 6, No. 2 (2015)
  • Coordination of Interdependent Natural Gas and Electricity Infrastructures
           for Firming the Variability of Wind Energy in Stochastic Day-Ahead
    • Authors: Alabdulwahab; A.;Abusorrah, A.;Xiaping Zhang;Shahidehpour, M.;
      Pages: 606 - 615
      Abstract: In this paper, the coordination of constrained electricity and natural gas infrastructures is considered for firming the variability of wind energy in electric power systems. The stochastic security-constrained unit commitment is applied for minimizing the expected operation cost in the day-ahead scheduling of power grid. The low cost and sustainable wind energy could substitute natural gas-fired units, which are constrained by fuel availability and emission. Also, the flexibility and quick ramping capability of natural gas units could firm the variability of wind energy. The electricity and natural gas network constraints are considered in the proposed model (referred to as EGTran) and Benders decomposition is adopted to check the natural gas network feasibility. The autoregressive moving average (ARMA) time-series model is used to simulate wind speed forecast errors in multiple Monte Carlo scenarios. Illustrative examples demonstrate the effectiveness of EGTran for firming the variable wind energy by coordinating the constrained electricity and natural gas delivery systems.
      PubDate: April 2015
      Issue No: Vol. 6, No. 2 (2015)
  • An Integrated Dynamic Voltage Restorer-Ultracapacitor Design for Improving
           Power Quality of the Distribution Grid
    • Authors: Somayajula; D.;Crow, M.L.;
      Pages: 616 - 624
      Abstract: Cost of various energy storage technologies is decreasing rapidly and the integration of these technologies into the power grid is becoming a reality with the advent of smart grid. Dynamic voltage restorer (DVR) is one product that can provide improved voltage sag and swell compensation with energy storage integration. Ultracapacitors (UCAP) have low-energy density and high-power density ideal characteristics for compensation of voltage sags and voltage swells, which are both events that require high power for short spans of time. The novel contribution of this paper lies in the integration of rechargeable UCAP-based energy storage into the DVR topology. With this integration, the UCAP-DVR system will have active power capability and will be able to independently compensate temporary voltage sags and swells without relying on the grid to compensate for faults on the grid like in the past. UCAP is integrated into dc-link of the DVR through a bidirectional dc-dc converter, which helps in providing a stiff dc-link voltage, and the integrated UCAP-DVR system helps in compensating temporary voltage sags and voltage swells, which last from 3 s to 1 min. Complexities involved in the design and control of both the dc-ac inverter and the dc-dc converter are discussed. The simulation model of the overall system is developed and compared to the experimental hardware setup.
      PubDate: April 2015
      Issue No: Vol. 6, No. 2 (2015)
  • Demand Response Management for Smart Grids With Wind Power
    • Authors: Cicek; N.;Delic, H.;
      Pages: 625 - 634
      Abstract: In this paper, we study demand response (DR) management when a wind farm is connected to a smart grid. Total social welfare, defined in terms of consumer utility and cost of power production, is maximized while the probability of power deficit due to the uncertainty in renewable production is limited by an upper bound. We find the optimal deficit-limiting conventional power production and consumption schedules, and demonstrate their superiority over competing policies, particularly when the renewable share is high. It is also noted that geographically diverse turbines (or wind farms) should be connected to the grid to ensure less variable power output and low enough probability of deficit.
      PubDate: April 2015
      Issue No: Vol. 6, No. 2 (2015)
  • Load Balancing With EV Chargers and PV Inverters in Unbalanced
           Distribution Grids
    • Authors: Weckx; S.;Driesen, J.;
      Pages: 635 - 643
      Abstract: Balanced three-phase four-wire distribution grids can host significantly more distributed generation and electric vehicles. Three-phase photovoltaic (PV) inverters and electric vehicle (EV) chargers can be adapted to transfer power from highly loaded to less loaded phases, without overloading the inverter or charger. Grid conditions will be improved due to a more balanced operation of the network and more PV panels and EVs can be connected before the limits of the network are reached. A classic coordinated charging strategy for EVs is adapted in this paper. It is shown that the charging of EVs can be improved when power can be transferred from one phase to another. Using PV inverters with a balancing inverter, the power injected in each phase will become a controllable variable as the total amount of produced power does not necessarily need to be equally divided across the three phases. The improvements made by using EV chargers and PV inverters that can balance the network are investigated. Several load flow simulations with realistic data show a positive effect on the system losses, the grid voltage, and voltage unbalance. Finally, a local controller is proposed to control the balancing between the phases when a real-time communication channel is not available.
      PubDate: April 2015
      Issue No: Vol. 6, No. 2 (2015)
  • An Optimal Maximum Power Point Tracking Algorithm for PV Systems With
           Climatic Parameters Estimation
    • Authors: Chikh; A.;Chandra, A.;
      Pages: 644 - 652
      Abstract: This paper presents a maximum power point tracking (MPPT) method for photovoltaic (PV) systems with reduced hardware setup. It is realized by calculating the instantaneous conductance and the junction conductance of the array. The first one is done using the array voltage and current, whereas the second one, which is a function of the array junction current, is estimated using an adaptive neuro-fuzzy (ANFIS) solar cell model. Knowing the difficulties of measuring solar radiation and cell temperature, since those require two extra sensors that will increase the hardware circuitry and measurement noise, an analytical model is proposed to estimate them with a denoising-based wavelet algorithm. The proposed MPPT technique helps to reduce the hardware setup using only one voltage sensor, while increases the array power efficiency and MPPT response time. The simulation and experimental results are provided to validate the MPPT algorithm operation as well as the climatic parameters estimation capabilities.
      PubDate: April 2015
      Issue No: Vol. 6, No. 2 (2015)
  • Erratum to “Up-Wave and Autoregressive Methods for Short-Term Wave
           Forecasting for an Oscillating Water Column” [Jan 15 171-178]
    • Authors: Paparella; F.;Monk, K.;Winands, V.;Lopes, M.F.P.;Conley, D.;Ringwood, J.V.;
      Pages: 653 - 653
      Abstract: In the above paper (ibid., vol. 6, no. 1, pp. 171-178, Jan. 2015), the acknowledgement of financial support was not included, due to a publication error. It is presented here.
      PubDate: April 2015
      Issue No: Vol. 6, No. 2 (2015)
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