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  Subjects -> ENGINEERING (Total: 2235 journals)
    - CHEMICAL ENGINEERING (188 journals)
    - CIVIL ENGINEERING (178 journals)
    - ELECTRICAL ENGINEERING (102 journals)
    - ENGINEERING (1194 journals)
    - ENGINEERING MECHANICS AND MATERIALS (374 journals)
    - HYDRAULIC ENGINEERING (54 journals)
    - INDUSTRIAL ENGINEERING (60 journals)
    - MECHANICAL ENGINEERING (85 journals)

ELECTRICAL ENGINEERING (102 journals)                  1 2     

3C TIC     Open Access  
Actuators     Open Access   (Followers: 1)
Advances in Electrical Engineering     Open Access   (Followers: 7)
Advances in Microelectronic Engineering     Open Access   (Followers: 6)
Advances in Signal Processing     Open Access   (Followers: 4)
American Journal of Electrical and Electronic Engineering     Open Access   (Followers: 15)
American Journal of Sensor Technology     Open Access   (Followers: 2)
APSIPA Transactions on Signal and Information Processing     Open Access   (Followers: 6)
Archives of Control Sciences     Open Access   (Followers: 2)
Archives of Electrical Engineering     Open Access   (Followers: 11)
Atom Indonesia     Open Access   (Followers: 1)
Bulletin of Electrical Engineering and Informatics     Open Access   (Followers: 10)
Circuits, Systems, and Signal Processing     Hybrid Journal   (Followers: 11)
Computers & Electrical Engineering     Hybrid Journal   (Followers: 10)
Current Trends in Signal Processing     Full-text available via subscription   (Followers: 4)
Edu Elektrika Journal     Open Access  
Electric Power Components and Systems     Hybrid Journal   (Followers: 8)
Electric Power Systems Research     Partially Free   (Followers: 16)
Electrical and Electronic Engineering     Open Access   (Followers: 16)
Electrical and Power Engineering Frontier     Open Access   (Followers: 16)
Electrical Engineering     Hybrid Journal   (Followers: 16)
Electrical Engineering and Automation     Open Access   (Followers: 3)
Electrical Engineering in Japan     Hybrid Journal   (Followers: 7)
Electrical, Control and Communication Engineering     Open Access   (Followers: 10)
Emerging and Selected Topics in Circuits and Systems     Hybrid Journal   (Followers: 5)
EURASIP Journal on Advances in Signal Processing     Open Access   (Followers: 7)
Ferroelectrics     Hybrid Journal   (Followers: 2)
Ferroelectrics Letters Section     Hybrid Journal   (Followers: 1)
Frequenz     Hybrid Journal   (Followers: 3)
Frontiers of Electrical and Electronic Engineering     Hybrid Journal   (Followers: 8)
IEA Electricity Information     Full-text available via subscription   (Followers: 6)
IEEE Access     Open Access   (Followers: 27)
IEEE Electrical Insulation Magazine     Full-text available via subscription   (Followers: 10)
IEEE Signal Processing Magazine     Full-text available via subscription   (Followers: 47)
IEEE Transactions on Control of Network Systems     Hybrid Journal   (Followers: 7)
IEEE Transactions on Dielectrics and Electrical Insulation     Hybrid Journal   (Followers: 7)
IEEE Transactions on Signal and Information Processing over Networks     Full-text available via subscription   (Followers: 1)
IEEJ Transactions on Electrical and Electronic Engineering     Hybrid Journal   (Followers: 9)
IET Control Theory & Applications     Hybrid Journal   (Followers: 12)
IET Electric Power Applications     Hybrid Journal   (Followers: 13)
IET Electrical Systems in Transportation     Hybrid Journal   (Followers: 8)
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: 10)
International Journal of Electrical Engineering Education     Full-text available via subscription   (Followers: 6)
International Journal of Electrical Power & Energy Systems     Open Access   (Followers: 15)
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: 5)
International Journal on Communication     Full-text available via subscription   (Followers: 13)
International Journal on Control System and Instrumentation     Full-text available via subscription   (Followers: 11)
International Journal on Electrical and Power Engineering     Full-text available via subscription   (Followers: 10)
International Journal on Signal and Image Processing     Full-text available via subscription   (Followers: 3)
International Transaction of Electrical and Computer Engineers System     Open Access  
International Transactions on Electrical Energy Systems     Hybrid Journal   (Followers: 7)
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: 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: 7)
Journal of Electrical Bioimpedance     Full-text available via subscription   (Followers: 2)
Journal of Electrical Engineering     Open Access   (Followers: 10)
Journal of Electrical Engineering & Electronic Technology     Hybrid Journal   (Followers: 3)
Journal of Electrical Systems and Information Technology     Open Access  
Journal of Field Robotics     Hybrid Journal   (Followers: 2)
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: 4)
Journal of the Society for Information Display     Hybrid Journal   (Followers: 1)
Journal of World's Electrical Engineering and Technology     Open Access  
Journal of Zhejiang University SCIENCE C     Hybrid Journal  
Jurnal Ilmiah Mahasiswa SPEKTRUM     Open Access  
Jurnal Infotel     Open Access  
Jurnal Nasional Teknik Elektro     Open Access   (Followers: 1)
Jurnal Rekayasa Elektrika     Open Access  
Majalah Ilmiah Teknologi Elektro : Journal of Electrical Technology     Open Access   (Followers: 1)
Majlesi Journal of Electrical Engineering     Open Access  
Micro and Nano Systems Letters     Open Access   (Followers: 4)
Nanotechnology Development     Open Access   (Followers: 5)
Oil, Gas, Coal and Electricity - Quarterly Statistics - Electricite, charbon, gaz et petrole - Statistiques trimestrielles     Full-text available via subscription   (Followers: 10)
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: 9)
Synthesis Lectures on Electrical Engineering     Full-text available via subscription   (Followers: 1)
System analysis and applied information science     Open Access  
Telematique     Open Access  
TELKOMNIKA : Indonesian Journal of Electrical Engineering     Open Access   (Followers: 10)
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   (Followers: 2)

        1 2     

Journal Cover Sustainable Energy, IEEE Transactions on
  [SJR: 2.826]   [H-I: 24]   [9 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  [177 journals]
  • IEEE Transactions on Sustainable Energy society information
    • Abstract: Provides a listing of current committee members and society officers.
      PubDate: Jan. 2016
      Issue No: Vol. 7, No. 1 (2016)
       
  • IEEE Power Engineering Society information for authors
    • Abstract: Provides instructions and guidelines to prospective authors who wish to submit manuscripts.
      PubDate: Jan. 2016
      Issue No: Vol. 7, No. 1 (2016)
       
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    • Abstract: This page or pages intentionally left blank.
      PubDate: Jan. 2016
      Issue No: Vol. 7, No. 1 (2016)
       
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    • Abstract: This page or pages intentionally left blank.
      PubDate: Jan. 2016
      Issue No: Vol. 7, No. 1 (2016)
       
  • Table of contents
    • Pages: 2
      Abstract: Presents the cover/table of contents for this issue of the periodical.
      PubDate: Jan. 2016
      Issue No: Vol. 7, No. 1 (2016)
       
  • IEEE Transactions on Sustainable Energy
    • Abstract: Provides a listing of current staff, committee members and society officers.
      PubDate: Jan. 2016
      Issue No: Vol. 7, No. 1 (2016)
       
  • A Resistance Emulation Approach to Optimize the Wave Energy Harvesting for
           a Direct Drive Point Absorber
    • Authors: Mendonca; H.;Martinez, S.;
      Pages: 3 - 11
      Abstract: In general, a major challenge for the exploitation of renewable energies is to improve their efficiency. In electricity generation from the energy of ocean waves, not unlike other technologies, the converter must be optimized to make the energy harvesting economically feasible. This paper proposes a passive tuning control strategy of a point absorber in which the power captured is maximized by controlling the electromagnetic force of the generator with a resistance emulation approach. The proposed strategy consists of mapping the optimal values for regular waves and applying them to irregular waves. This strategy is tested in a wave energy converter in which the generator is connected to a boost rectifier converter whose controller is designed to emulate a resistance. The power electronics system implemented is validated by comparing its performance with the case in which the generator is directly connected to a resistive load. The simulation results show the effectiveness of the proposed strategy as the maximum captured power is concentrated around the optimal values previously calculated and with the same behavior for both excitations.
      PubDate: Jan. 2016
      Issue No: Vol. 7, No. 1 (2016)
       
  • Combined Heat and Power Dispatch Considering Pipeline Energy Storage of
           District Heating Network
    • Authors: Zhigang Li;Wenchuan Wu;Shahidehpour; M.;Jianhui Wang;Boming Zhang;
      Pages: 12 - 22
      Abstract: The regional integration of variable wind power could be restricted by a strong coupling of electric power generation dispatch and heat supply of combined heat-and-power (CHP) units. The coupling in cold seasons precludes CHPs from providing the necessary flexibility for managing the wind power dispatch. The lack of flexibility problem can be tackled by exploiting the energy storage capability of a district heating network (DHN) which decouples the strong linkage of electric power and heat supplies. In this paper, a combined heat and power dispatch (CHPD) is formulated to coordinate the operation of electric power system (EPS) and district heating system (DHS). The proposed CHPD model which is solved by an iterative method considers the temperature dynamics of DHN for exploiting energy storage as an option for managing the variability of wind energy. The simulation results are discussed for several test systems to demonstrate the potential benefits of the proposed method in terms of operation economics, wind power utilization, as well as the potential benefits for real systems.
      PubDate: Jan. 2016
      Issue No: Vol. 7, No. 1 (2016)
       
  • Bumpless Transfer-Based Inter-Region Controller Switching of Wind Turbines
           for Reducing Power and Load Fluctuation
    • Authors: Quan Chen;Yaoyu Li;Seem; J.E.;
      Pages: 23 - 31
      Abstract: For wind turbine operation, wind variations around the rated wind speed can lead to frequent controller switching actions, which may result in significant fluctuation in power output and structural load. This paper presents a bumpless transfer scheme for the inter-region controller switching for variable-speed variable-pitch wind turbines, which aims to reduce the associated power fluctuation and fatigue load. The study follows a typical partition of Region 2 (maximum power capture control), Region 2.5 (rotor speed regulation), and Region 3 (constant power control) around the rated wind speed. Two relatively simple bumpless transfer techniques, i.e., 1)the conditioning technique and 2)the linear quadratic (LQ) technique, respectively, are employed for different situations of inter-region controller switching. The conditioning bumpless transfer approach is adopted for switching between Regions 2 and 2.5 via generator torque control. The LQ bumpless transfer technical is applied to the switching between Regions 2.5 and 3, when the generator torque is saturated at its rated value, the pitch controller takes over so as to limit the load of wind turbine. The simulation results demonstrated the effectiveness of the proposed scheme of inter-region switching, with significant reduction of power flicker and structural load.
      PubDate: Jan. 2016
      Issue No: Vol. 7, No. 1 (2016)
       
  • An Online Frequency Tracking Algorithm Using Terminal Voltage Spectroscopy
           for Battery Optimal Charging
    • Authors: Hussein; A.A.;Fardoun, A.A.;Stephen, S.S.;
      Pages: 32 - 40
      Abstract: This paper proposes an online tracking algorithm to allocate and track the optimal charging frequency for common batteries in real time under any condition. The optimal frequency refers to the frequency of the sinusoidal component of the charging current at which the internal ac impedance of the battery is minimal. The ac impedance depends on the physical properties of the batterys electrodes and electrolyte. It also varies nonlinearly with temperature, state-of-charge (SOC), and state-of-health (SOH). Although the ac impedance can be determined offline using sophisticated ac battery models or measurement equipment, there is no direct way to measure it in real time. The proposed technique has the capability of allocating and tracking the optimal frequency in real time without using an ac battery model or measurement equipment. Moreover, the proposed technique is simple, inexpensive to implement, and applicable to any battery cell or pack. Derivation of the proposed technique is presented and followed by simulation and experimental verification.
      PubDate: Jan. 2016
      Issue No: Vol. 7, No. 1 (2016)
       
  • Wind Turbine Inverter Robust Loop-Shaping Control Subject to Grid
           Interaction Effects
    • Authors: Gryning; M.P.S.;Qiuwei Wu;Blanke, M.;Niemann, H.H.;Andersen, K.P.H.;
      Pages: 41 - 50
      Abstract: An H∞ robust control of wind turbine (WT) inverters employing an inductor-capacitor-inductor (LCL) filter is proposed in this paper. The controller dynamics are designed for selective harmonic filtering in an offshore transmission network subject to parameter perturbations. Parameter uncertainty in the network originates from the grid and the number of WTs connected. Power converter-based turbines inject harmonic currents, which are attenuated by passive filters. A robust high-order active filter controller is proposed to complement the passive filtering. The H∞ design of the control loop enables desired tracking with integral effect while bounding the induced change. The design was tested in an aggregated model of the London Array offshore wind power plant and compared with traditional Proportional-Integral (PI) controller designs. Robust stability and performance and a reduction of control effort by 25% are obtained over the full envelope of operation.
      PubDate: Jan. 2016
      Issue No: Vol. 7, No. 1 (2016)
       
  • Electrical Oscillations in Wind Farm Systems: Analysis and Insight Based
           on Detailed Modeling
    • Authors: Kunjumuhammed; L.P.;Pal, B.C.;Oates, C.;Dyke, K.J.;
      Pages: 51 - 62
      Abstract: This paper presents modeling and analysis of electrical oscillations in a wind farm system. The detailed modeling and modal analysis of a wind farm system are presented in this paper. The approach to modeling uses detailed representation of a wind turbine generator and collection system including high-voltage direct-current (HVDC) power converter system control, facilitating a comprehensive analysis of the wind farm system. Various modes are classified according to the frequency of oscillation. The detailed modal analysis is used to characterize the critical modes. Time-domain simulation also confirms the presence of these modes. The effect of wind farm operating conditions and voltage source converter control tuning on critical oscillatory modes are also assessed and discussed in detail.
      PubDate: Jan. 2016
      Issue No: Vol. 7, No. 1 (2016)
       
  • Advanced Auxiliary Control of an Energy Storage Device for Transient
           Voltage Support of a Doubly Fed Induction Generator
    • Authors: Yang-Wu Shen;De-Ping Ke;Yuan-Zhang Sun;Kirschen; D.S.;Wei Qiao;Xiang-Tian Deng;
      Pages: 63 - 76
      Abstract: This paper proposes to employ an energy storage device (ESD) to assist a doubly fed induction generator (DFIG) in providing the required reactive power to the grid during severe grid faults. The energy storage side converter (ESC) that connects the ESD to the rotor circuit is placed in parallel and coordinated with the normally sized rotor-side converter (RSC) to provide the rotor demagnetizing and reactive currents. Moreover, by appropriate distribution of these two rotor current components between the ESC and the RSC, the required current rating of the ESC and the energy capacity of the ESD are optimized. In particular, this paper proposes to utilize the ESD for the above control objective in an auxiliary control manner, where the primary objective of the ESD is also for steady-state active power regulation for the DFIG. This improves the overall performance/cost ratio of the ESD. The proposed use of the ESD for the transient reactive power control of the DFIG is not only a technically advanced but also economically feasible and promising alternative to the existing control methods for enhancing the transient performance of DFIGs. Numerical simulations are performed to validate the proposed control method.
      PubDate: Jan. 2016
      Issue No: Vol. 7, No. 1 (2016)
       
  • A Near-Optimal Model-Based Control Algorithm for Households Equipped With
           Residential Photovoltaic Power Generation and Energy Storage Systems
    • Authors: Yanzhi Wang;Xue Lin;Pedram; M.;
      Pages: 77 - 86
      Abstract: Integrating residential photovoltaic (PV) power generation and energy storage systems into the Smart Grid is an effective way of reducing fossil fuel consumptions. This has become a particularly interesting problem with the introduction of dynamic electricity energy pricing, since consumers can use their PV-based energy generation and controllable energy storage devices for peak shaving on their power demand profile, thereby minimizing their electricity bill. A realistic electricity pricing function is considered with billing period of a month, comprising both an energy price component and a demand price component. Due to the characteristics of electricity price function and energy storage capacity limitation, the residential storage control algorithm should 1)utilize PV power generation and load power consumption predictions and 2)account for various energy loss components during system operation, including energy loss components due to rate capacity effect in the storage system and power dissipation of the power conversion circuitry. A near-optimal storage control algorithm is proposed accounting for these aspects. The near-optimal algorithm, which controls the charging/discharging of the storage system, is effectively implemented by solving a convex optimization problem at the beginning of each day with polynomial time complexity. For further improvement, the reinforcement learning technique is adopted to adaptively determine the residual energy in the storage system at the end of each day in a billing period.
      PubDate: Jan. 2016
      Issue No: Vol. 7, No. 1 (2016)
       
  • Hybrid Probabilistic Wind Power Forecasting Using Temporally Local
           Gaussian Process
    • Authors: Juan Yan;Kang Li;Er-Wei Bai;Jing Deng;Foley; A.M.;
      Pages: 87 - 95
      Abstract: The demand for sustainable development has resulted in a rapid growth in wind power worldwide. Although various approaches have been proposed to improve the accuracy and to overcome the uncertainties associated with traditional methods, the stochastic and variable nature of wind still remains the most challenging issue in accurately forecasting wind power. This paper presents a hybrid deterministicprobabilistic method where a temporally local moving window technique is used in Gaussian process (GP) to examine estimated forecasting errors. This temporally local GP employs less measurement data with faster and better predictions of wind power from two wind farms, one in the USA and the other in Ireland. Statistical analysis on the results shows that the method can substantially reduce the forecasting error while it is more likely to generate Gaussian-distributed residuals, particularly for short-term forecast horizons due to its capability to handle the time-varying characteristics of wind power.
      PubDate: Jan. 2016
      Issue No: Vol. 7, No. 1 (2016)
       
  • An Efficient Modeling Technique to Simulate and Control
           Submodule-Integrated PV System for Single-Phase Grid Connection
    • Authors: Khan; O.;Weidong Xiao;
      Pages: 96 - 107
      Abstract: The photovoltaic (PV) system that is based on submodule-integrated converters (subMICs) is capable of maximizing solar energy harvest by eradicating power losses due to intrapanel mismatch. Modeling and simulation of subMIC-based systems are important to study the effect of PV partial shading, prove new control strategies, analyze distributed system dynamics, optimize system configurations, and determine system parameters, etc. However, the simulation of such systems can be very challenging due to the large number of switching-mode power units, nonlinear nature of PV generators, and complication of the coordinating control. This paper provides an effective solution to simulate and control single-phase grid-tied PV systems that are based on a practical subMICs configuration. The approach includes the simplified PV cell model and averaged model for power converters, which consider all dynamic interactions among the maximum power point tracking (MPPT), PV submodule voltage regulation, dc-link voltage control, and double frequency ripple. The effectiveness of the proposed simulation and the subMIC system is validated by the comparison with a practical system based on centralized PV inverter under the real-world solar irradiance and various PV mismatch conditions, e.g., partial shading and uneven temperature distribution etc.
      PubDate: Jan. 2016
      Issue No: Vol. 7, No. 1 (2016)
       
  • Capacity-Fading Model of Lithium-Ion Battery Applicable to Multicell
           Storage Systems
    • Authors: Kakimoto; N.;Goto, K.;
      Pages: 108 - 117
      Abstract: This paper proposes a capacity-fading model of a lithium-ion (Li-ion) battery. The model includes two capacity fade mechanisms, i.e., loss of lithium and increased cell resistance. It is based on a conventional model consisting of a voltage source and three internal resistances. The voltage source is a function of the amount of lithium in the positive electrode. The shape of voltage curve is affected by the discharging current. Its effect is larger than that of internal resistances, and is included in the model. Some parameters vary with the cumulative charge involved in the cycling. A closed form of the capacity is derived. The model reproduces variation in voltage curve due to the capacity fading. The model is applied to a pack of four parallel-connected batteries. It is degraded as a single battery, but some unevenness exists among batteries. The model accurately expresses their behaviors.
      PubDate: Jan. 2016
      Issue No: Vol. 7, No. 1 (2016)
       
  • A Fully Coupled Wave-to-Wire Model of an Array of Wave Energy Converters
    • Authors: Forehand; D.I.M.;Kiprakis, A.E.;Nambiar, A.J.;Wallace, A.R.;
      Pages: 118 - 128
      Abstract: This paper describes a fully coupled, wave-to-wire time-domain model that can simulate the hydrodynamic, mechanical, and electrical response of an array of wave energy converters. Arrays of any configuration can be simulated to explore both the effects of the array on the electricity network and of network events on the devices within the array. State-space modeling of the hydrodynamic radiation forces enables fast and accurate prediction of the interacting response of multiple devices, including the effects of wave climate, control strategies, and network power flow. Case studies include the demonstration of the bidirectional interaction of the array and the network.
      PubDate: Jan. 2016
      Issue No: Vol. 7, No. 1 (2016)
       
  • A Time-Dependent Approach to Evaluate Capacity Value of Wind and Solar PV
           Generation
    • Authors: Mosadeghy; M.;Ruifeng Yan;Saha, T.K.;
      Pages: 129 - 138
      Abstract: Contribution of renewable energies in power systems is increasing due to continuous growth of wind and solar generators. Because of intermittency and uncertainty of these resources, conventional reliability evaluation methods are not applicable and different techniques have been developed to model these generators. However, most of these methods are time-consuming or may not be able to keep time dependency and correlations between renewable resources and load. Therefore, this paper intends to improve the existing methods and proposes a fast and simple approach. In this approach, wind power, photovoltaic (PV) generation, and electricity demand have been modeled as time-dependent clusters, which not only can capture their time-dependent attributes, but also are able to keep the correlations between these data sets. To illustrate the effectiveness of this framework, the proposed methodology has been applied on two different case studies: 1)IEEE RTS system and 2)South Australia (SA) power network. The developed technique is validated by comparing results with sequential Monte Carlo technique.
      PubDate: Jan. 2016
      Issue No: Vol. 7, No. 1 (2016)
       
  • Multiobjective Stochastic Economic Dispatch With Variable Wind Generation
           Using Scenario-Based Decomposition and Asynchronous Block Iteration
    • Authors: Yimu Fu;Mingbo Liu;Licheng Li;
      Pages: 139 - 149
      Abstract: We investigated a multiobjective stochastic economic dispatch (MOSED) problem considering variable wind power integration. We transformed this problem into an equivalent large-scale multiobjective deterministic optimization model based on the scenario method. We simultaneously minimized power purchase costs and polluting gas emissions. We introduced the normal boundary intersection (NBI) method to convert the multiobjective optimization (MOO) model into a series of single-objective optimization (SOO) problems, which we solved using the interior-point method (IPM). In the process used to solve each SOO problem, we rearranged the coefficient matrix of the correction equation in the block bordered diagonal form (BBDF) according to the sequence of the forecast scenario and sampling scenarios. Thus, we were able to decompose this correction equation further into a number of low-dimensional equations corresponding to the forecast scenario and sampling scenarios, respectively, and solve them using the asynchronous block iteration method. Furthermore, we implemented the proposed algorithm on an IEEE 39-bus system and a real-provincial power system, and built a parallel computational framework on high-performance clusters to demonstrate the enhancements in computational speed and the reduced memory requirements obtained by parallelization. Through this framework, one can obtain scheduling of the outputs of generators on a day-ahead basis.
      PubDate: Jan. 2016
      Issue No: Vol. 7, No. 1 (2016)
       
  • An Optimized Swinging Door Algorithm for Identifying Wind Ramping Events
    • Authors: Mingjian Cui;Jie Zhang;Florita; A.R.;Hodge, B.-M.;Deping Ke;Yuanzhang Sun;
      Pages: 150 - 162
      Abstract: With the increasing penetration of renewable energy in recent years, wind power ramp events (WPREs) have started affecting the economic and reliable operation of power grids. In this paper, we develop an optimized swinging door algorithm (OpSDA) to improve the state of the art in WPREs detection. The swinging door algorithm (SDA) is utilized to segregate wind power data through a piecewise linear approximation. A dynamic programming algorithm is performed to optimize the segments by: 1)merging adjacent segments with the same ramp changing direction; 2)handling wind power bumps; and 3)postprocessing insignificant-ramps intervals. Measured wind power data from two case studies are utilized to evaluate the performance of the proposed OpSDA. Results show that the OpSDA provides 1)significantly better performance than the SDA and 2)equal-to-better performance compared to the L1-Ramp Detect with Sliding Window (L1-SW) method with significantly less computational time.
      PubDate: Jan. 2016
      Issue No: Vol. 7, No. 1 (2016)
       
  • Integrated Bidding and Operating Strategies for Wind-Storage Systems
    • Authors: Huajie Ding;Pinson; P.;Zechun Hu;Yonghua Song;
      Pages: 163 - 172
      Abstract: Due to their flexible charging and discharging capabilities, energy storage systems (ESS) are considered a promising complement to wind farms (WFs) participating in electricity markets. This paper presents integrated day-ahead bidding and real-time operation strategies for a wind-storage system to perform arbitrage and to alleviate wind power deviations from day-ahead contracts. The strategy is developed with two-price balancing markets in mind. A mixed integer nonlinear optimization formulation is built to determine optimal offers by taking into account expected wind power forecasting errors and the power balancing capability of the ESS. A modified gradient descent algorithm is designed to solve this nonlinear problem. A number of case studies validate the computational efficiency and optimality of the algorithm. Compared to the existing strategies, the proposed strategies yield increased economic profit, regardless of the temporal dependence of wind power forecasting errors.
      PubDate: Jan. 2016
      Issue No: Vol. 7, No. 1 (2016)
       
  • Mitigation Control Against Partial Shading Effects in Large-Scale PV Power
           Plants
    • Authors: Rahmann; C.;Vittal, V.;Ascui, J.;Haas, J.;
      Pages: 173 - 180
      Abstract: This study proposes a novel control strategy to allow partially shaded photovoltaic power plants (PV-PPs) to mitigate the detrimental effects on the frequency of power systems without the need for energy storage. The strategy divides the PV-PP into N sections operating in a deloaded mode with a specific reserve level. A central controller continually monitors each of these PV sections. When one or more sections are under shaded conditions, the control orders the unshaded sections to deploy their active power reserves to smooth the power output at the interconnection point of the PV-PP. The proposed control was tested in the isolated power system of northern Chile considering different PV scenarios and levels of deload. Results show that the control is effective in assisting frequency regulation, especially under large PV penetration scenarios. For these cases, and only on days with high irradiance variability, the benefits gained from the control strategy could be more valuable for the system than the forgone revenues due to the deloaded operation.
      PubDate: Jan. 2016
      Issue No: Vol. 7, No. 1 (2016)
       
  • A New MPPT Design Using Grey Wolf Optimization Technique for Photovoltaic
           System Under Partial Shading Conditions
    • Authors: Mohanty; S.;Subudhi, B.;Ray, P.K.;
      Pages: 181 - 188
      Abstract: This paper presents a maximum power point tracking (MPPT) design for a photovoltaic (PV) system using a grey wolf optimization (GWO) technique. The GWO is a new optimization method which overcomes the limitations such as lower tracking efficiency, steady-state oscillations, and transients as encountered in perturb and observe (P&O) and improved PSO (IPSO) techniques. The problem of tracking the global peak (GP) of a PV array under partial shading conditions (PSCs) is attempted employing the GWO-based MPPT technique. The proposed scheme is studied for a PV array under PSCs which exhibits multiple peaks and its tracking performance is compared with that of two MPPT algorithms, namely P&O-MPPT and IPSO-MPPT. The proposed GWO-MPPT algorithm is implemented on a PV system using MATLAB/SIMULINK. Furthermore, an experimental setup is developed to verify the efficacy of the proposed system. From the obtained simulation and experimental results, it is observed that the proposed MPPT algorithm outperforms both P&O and IPSO MPPTs.
      PubDate: Jan. 2016
      Issue No: Vol. 7, No. 1 (2016)
       
  • Balanced Control Strategies for Interconnected Heterogeneous Battery
           Systems
    • Authors: Le Yi Wang;Caisheng Wang;Yin; G.;Feng Lin;Polis, M.P.;Caiping Zhang;Jiuchun Jiang;
      Pages: 189 - 199
      Abstract: This paper develops new balanced charge/discharge strategies that distribute charge or discharge currents properly so that during operation, battery systems maintain uniform state-of-charge (SOC) all the time. The proposed balanced charge/discharge control strategies are useful for interconnected heterogeneous battery systems that can be built from battery modules with different types, ages, and power/capacity ratings. Both voltage-based and SOC-based balanced charge/discharge strategies are developed. Their convergence properties are rigorously established, and illustrative examples using production batteries demonstrate their convergence behavior under different charging current profiles. The approach will be especially useful for battery storage systems to support power grids with renewable energy sources where the battery systems are required to operate continuously.
      PubDate: Jan. 2016
      Issue No: Vol. 7, No. 1 (2016)
       
  • A Novel Probabilistic Optimal Power Flow Model With Uncertain Wind Power
           Generation Described by Customized Gaussian Mixture Model
    • Authors: Deping Ke;Chung; C.Y.;Yuanzhang Sun;
      Pages: 200 - 212
      Abstract: A novel probabilistic optimal power flow (P-OPF) model with chance constraints that considers the uncertainties of wind power generation (WPG) and load is proposed in this paper. An affine generation dispatch strategy is adopted to balance the system power uncertainty by several conventional generators, and thus the linear approximation of the cost function with respect to the power uncertainty is proposed to compute the quantile (which is also recognized as the value-at-risk) corresponding to a given probability value. The proposed model applies this quantile as the objective function and minimizes it to meet distinct probabilistic cost regulation purposes via properly selecting the given probability. In particular, the hedging effect due to the used affine generation dispatch is also thoroughly investigated. In addition, an analytical method to calculate probabilistic load flow (PLF) is developed with the probability density function of WPG, which is proposed to be approximated by a customized Gaussian mixture model whose parameters are easily obtained. Accordingly, it is successful to analytically compute the chance constraints on the transmission line power and the power outputs of conventional units. Numerical studies of two benchmark systems show the satisfactory accuracy of the PLF method, and the effectiveness of the proposed P-OPF model.
      PubDate: Jan. 2016
      Issue No: Vol. 7, No. 1 (2016)
       
  • Coordinated Frequency Control Using MT-HVDC Grids With Wind Power Plants
    • Authors: Bianchi; F.D.;Dominguez-Garcia, J.L.;
      Pages: 213 - 220
      Abstract: In the last years, wind power has continuously increased the participation in the power generation share. For transmitting the power generated from wind power plants (WPPs)to AC grids, multiterminal high-voltage direct current (HVDC)systems are envisaged as the future backbone of a European SuperGrid interconnecting wind power generation with various AC grids and countries. This paper presents a coordinated control scheme in order that offshore WPPs connected through multiterminal HVDC systems are able to contribute to the primary frequency control of the land AC grids. The proposed control scheme is capable of achieving a suitable frequency regulation even under low wind power conditions by allowing also the power share among AC areas. The control scheme is evaluated by dynamic simulations in an adapted version of the Cigr DC grid benchmark with a five-terminal HVDC grid including two wind farms and three AC networks.
      PubDate: Jan. 2016
      Issue No: Vol. 7, No. 1 (2016)
       
  • Long-Term Renewable Energy Planning Model for Remote Communities
    • Authors: Arriaga; M.;Canizares, C.A.;Kazerani, M.;
      Pages: 221 - 231
      Abstract: This paper presents a novel long-term renewable energy (RE) planning model for remote communities (RCs), considering the characteristics of diesel-based RCs in Canada and other parts of the world such as Alaska and northern Chile. Over the past few years, there has been a significant increase in assessing and deploying RE projects in northern remote locations. The model proposed in this paper adds to such efforts by creating a multiple-year community planning tool that can be used to determine economic and technically feasible RE solutions, considering the current operating structures, electricity pricing systems, subsidy frameworks, and project funding alternatives under which RE can be deployed in RCs. The proposed model is implemented in a case study for the Kasabonika Lake First Nation community in northern Ontario. The case study shows that RE projects can be feasible under current operating conditions, for a set of funding alternatives that share the economic risks.
      PubDate: Jan. 2016
      Issue No: Vol. 7, No. 1 (2016)
       
  • Optimal Planning of Storage in Power Systems Integrated With Wind Power
           Generation
    • Authors: Peng Xiong;Singh; C.;
      Pages: 232 - 240
      Abstract: This paper proposes an approach for determining the optimal location and size of an energy storage system (ESS) in a power system network integrated with uncertain wind power generation. The uncertainty of wind power output is represented by a scenario tree model, so that the nonanticipative behavior of operating decisions under system uncertainties can be properly addressed. The proposed formulation is too huge to be solved directly, so a Benders decomposition algorithm is applied to reduce the computational burden. Case studies are conducted to illustrate the influence of ESS on power system operation. It is shown that increasing the capital investment on ESS can reduce the daily operating cost of the power system. A capital/operating cost frontier is presented in this paper to demonstrate the tradeoff between ESS capital investment and daily operating cost, and to show how ESS planning decisions are affected by the budget for investment.
      PubDate: Jan. 2016
      Issue No: Vol. 7, No. 1 (2016)
       
  • Short-Term Wind Speed or Power Forecasting With Heteroscedastic Support
           Vector Regression
    • Authors: Qinghua Hu;Shiguang Zhang;Man Yu;Zongxia Xie;
      Pages: 241 - 249
      Abstract: Wind speed or wind power forecasting plays an important role in large-scale wind power penetration due to their uncertainty. Support vector regression, widely used in wind speed or wind power forecasting, aims at discovering natural structures of wind variation hidden in historical data. Most current regression algorithms, including least squares support vector regression (SVR), assume that the noise of the data is Gaussian with zero mean and the same variance. However, it is discovered that the uncertainty of short-term wind speed satisfies Gaussian distribution with zero mean and heteroscedasticity in this work. This kind of task is called heteroscedastic regression. In order to deal with this problem, we derive an optimal loss function for heteroscedastic regression and develop a new framework of v-SVR for learning tasks of Gaussian noise (GN) with heteroscedasticity. In addition, we introduce the stochastic gradient descent (SGD) method to solve the proposed model, which leads the models to be trained online. Finally, we reveal the uncertainty properties of wind speed with two real-world datasets and test the proposed algorithms on these data. The experimental results confirm the effectiveness of the proposed model.
      PubDate: Jan. 2016
      Issue No: Vol. 7, No. 1 (2016)
       
  • Optimal Operation of Distributed Energy Storage Systems to Improve
           Distribution Network Load and Generation Hosting Capability
    • Authors: Jayasekara; N.;Masoum, M.A.S.;Wolfs, P.J.;
      Pages: 250 - 261
      Abstract: This paper proposes a strategy for optimal integration of battery energy storage systems (BESSs) to improve the load and distributed generation (DG) hosting ability of the utility grid. An effective tool that determines the optimal capacity and day-ahead operation strategy for deployment of distribution network operator (DNO)-controlled BESSs is presented. It is a cost-based multiobjective optimization strategy that considers two primary factors: 1)distribution system cost; and 2)battery cycling cost. Quantitative analyses on the benefits and tradeoffs of BESS installations are carried out considering different service options. BESS is investigated for three main service options: 1)voltage regulation; 2)loss reduction; and 3)peak reduction. The performance and benefits of the optimized BESS to control one service option exclusively or multiple services simultaneously is compared. The analysis is further extended to study the effect of installation site on the size, management strategy, and the service option. Results show that optimal integration of BESSs can realize maximum operational and cost benefits while effectively elevating the load and DG hosting capability of the network. The approach is developed using MATLAB interior-point algorithm. Simulations are conducted for the medium voltage (MV) IEEE 33 bus system and a low voltage (LV) distribution network in Western Australia studied during the Perth Solar City Trial.
      PubDate: Jan. 2016
      Issue No: Vol. 7, No. 1 (2016)
       
  • Dispatching and Frequency Control Strategies for Marine Current Turbines
           Based on Doubly Fed Induction Generator
    • Authors: Anwar; M.B.;El Moursi, M.S.;Weidong Xiao;
      Pages: 262 - 270
      Abstract: This paper presents the modeling and development of a dispatchable large-scale marine current turbine (MCT)farm equipped with power fluctuation compensation and primary frequency control schemes. The proposed control strategies rely on the regular and highly predictable power extraction from the marine currents, which are essentially governed by astronomical forces. Therefore, a mathematical model for prediction of marine current speed is developed and validated with the recorded measurements. Subsequently, the effect of velocity disturbances caused by the swell effect is studied and a battery energy storage station (BESS)control strategy for power fluctuation mitigation is proposed with reduced BESS capacity. Additionally, the provision of frequency control for MCT based on BESS has been discussed. The performance of the BESS-based frequency control strategy has been analyzed and compared with that of frequency control based on the combination of inertial response and deloaded operation. The simulation results depict that both these strategies can effectively enable MCTs to participate in primary frequency control, however, provision of frequency control based on BESS is more feasible in terms of profitability and reduction in fossil fuel consumption.
      PubDate: Jan. 2016
      Issue No: Vol. 7, No. 1 (2016)
       
  • A Simplified Model for Predicting Primary Control Inadequacy for
           Nonresponsive Wind Power
    • Authors: Chavez; H.;Reza Hezamsadeh, M.;Carlsson, F.;
      Pages: 271 - 278
      Abstract: The integration of wind power (WP) into power systems has led to concerns on the adequacy of primary frequency control. Such concerns have currently arisen in interconnections with high penetration of WP and may appear in other systems where high penetration of WP is planned. This paper proposes a method for predicting the level of WP penetration that may lead to primary frequency control inadequacy, considering a empirically-validated model of primary frequency control, worst-case scenario conditions and no frequency response from WP machines. The NORDEL interconnection is considered as a case study.
      PubDate: Jan. 2016
      Issue No: Vol. 7, No. 1 (2016)
       
  • Releasable Kinetic Energy-Based Inertial Control of a DFIG Wind Power
           Plant
    • Authors: Jinsik Lee;Muljadi; E.;Sorensen, P.;Yong Cheol Kang;
      Pages: 279 - 288
      Abstract: Wind turbine generators (WTGs) in a wind power plant (WPP) contain different levels of releasable kinetic energy (KE) because of the wake effects. This paper proposes a releasable KE-based inertial control scheme for a doubly fed induction generator (DFIG) WPP that differentiates the contributions of the WTGs depending on their stored KE. The proposed KE-based gain scheme aims to make use of the releasable KE in a WPP to raise the frequency nadir. To achieve this, two additional loops for the inertial control are implemented in each DFIG controller: the rate of change of frequency and droop loops. The proposed scheme adjusts the two loop gains in a DFIG controller depending on its rotor speed so that a DFIG operating at a higher rotor speed releases more KE. The performance of the proposed scheme was investigated under various wind conditions. The results clearly indicate that the proposed scheme successfully improves the frequency nadir more than the conventional same gain scheme by releasing more KE stored in a WPP, and it helps all WTGs to ensure stable operation during inertial control by avoiding the rotor speed reaching the minimum speed limit.
      PubDate: Jan. 2016
      Issue No: Vol. 7, No. 1 (2016)
       
  • Distributionally Robust Co-Optimization of Energy and Reserve Dispatch
    • Authors: Wei Wei;Feng Liu;Shengwei Mei;
      Pages: 289 - 300
      Abstract: This paper proposes a two-stage distributionally robust optimization model for the joint energy and reserve dispatch (D-RERD for short) of bulk power systems with significant renewable energy penetration. Distinguished from the prevalent uncertainty set-based and worst-case scenario oriented robust optimization methodology, we assume that the output of volatile renewable generation follows some ambiguous distribution with known expectations and variances, the probability distribution function (pdf) is restricted in a functional uncertainty set. D-RERD aims at minimizing the total expected production cost in the worst renewable power distribution. In this way, D-RERD inherits the advantages from both stochastic optimization and robust optimization: statistical characteristic is taken into account in a data-driven manner without requiring the exact pdf of uncertain factors. We present a convex optimization-based algorithm to solve the D-RERD, which involves solving semidefinite programming (SDP), convex quadratic programming (CQP), and linear programming (LP). The performance of the proposed approach is compared with the emerging adaptive robust optimization (ARO)-based model on the IEEE 118-bus system. Their respective features are discussed in case studies.
      PubDate: Jan. 2016
      Issue No: Vol. 7, No. 1 (2016)
       
  • A Two-Stage Robust Reactive Power Optimization Considering Uncertain Wind
           Power Integration in Active Distribution Networks
    • Authors: Tao Ding;Shiyu Liu;Wei Yuan;Zhaohong Bie;Bo Zeng;
      Pages: 301 - 311
      Abstract: Traditional reactive power optimization aims to minimize the total transmission losses by control reactive power compensators and transformer tap ratios, while guaranteeing the physical and operating constraints, such as voltage magnitudes and branch currents to be within their reasonable range. However, large amounts of renewable resources coming into power systems bring about great challenges to traditional planning and operation due to the stochastic nature. In most of the practical cases from China, the wind farms are centrally integrated into active distribution networks. By the use of conic relaxation based branch flow formulation, the reactive optimization problem in active distribution networks can be formulated as a mixed integer convex programming model that can be tractably dealt with. Furthermore, to address the uncertainties of wind power output, a two-stage robust optimization model is proposed to coordinate the discrete and continuous reactive power compensators and find a robust optimal solution that can hedge against any possible realization within the uncertain wind power output. Moreover, the second order cone programming-based column-and-constraint generation algorithm is employed to solve the proposed two-stage robust reactive power optimization model. Numerical results on 33-, 69- and 123-bus systems and comparison with the deterministic approach demonstrate the effectiveness of the proposed method.
      PubDate: Jan. 2016
      Issue No: Vol. 7, No. 1 (2016)
       
  • Distributed Frequency Control via Randomized Response of Electric Vehicles
           in Power Grid
    • Authors: Vedady Moghadam; M.R.;Rui Zhang;Ma, R.T.B.;
      Pages: 312 - 324
      Abstract: In this paper, we propose a new distributed frequency control scheme for electric vehicles (EVs) to help restore the power grid frequency upon a contingency of supply-demand imbalance. Under our scheme, each EV independently monitors the grid frequency at discrete times and responds by switching among its charging, idle, and discharging operational modes according to a simple threshold-based switching algorithm. To recover the grid frequency smoothly and prevent an undesired frequency overshoot/undershoot due to simultaneous response of EVs, we design the inter-response times of any EV to follow an exponentially distributed random variable with a certain mean value at each operational mode. To draw insights into the performance of our scheme, we characterize its impacts on the grid frequency in various aspects, including the mean and variance of the resulting grid frequency over time, the mean frequency recovery time, the average number of EV switching their modes, and the probability of frequency overshoot/undershoot. Accordingly, we formulate an optimization problem for the grid operator to minimize the expected cost of implementing our frequency control scheme by designing EVs response rates subject to their requested incentive prices and the given grid performance guarantees. Finally, we validate our analysis via simulations on the IEEE 9-Bus test system and the Ireland power system, where it is observed that our frequency control scheme can be used as a reliable and cost-efficient alternative for the conventional primary reserve service.
      PubDate: Jan. 2016
      Issue No: Vol. 7, No. 1 (2016)
       
  • Risk-Based Admissibility Assessment of Wind Generation Integrated into a
           Bulk Power System
    • Authors: Cheng Wang;Feng Liu;Jianhui Wang;Wei Wei;Shengwei Mei;
      Pages: 325 - 336
      Abstract: The increasing integration of large-scale volatile and uncertain wind generation has brought great challenges to power system operations. In this paper, a risk-based admissibility assessment approach is proposed to quantitatively evaluate how much wind generation can be accommodated by the bulk power system under a given unit commitment (UC) strategy. First, the operational risk brought by the variation and uncertainty of wind generation is developed as an admissibility measure of wind generation. Then its linear approximation is derived for practical implementation. Furthermore, a risk-minimization model is established to mathematically characterize the admissible region of wind generation. This model can be solved effectively by a modified column and constraint generation (C&CG) algorithm. Simulations on the IEEE 9-bus system and the real Guangdong power grid demonstrate the effectiveness and efficiency of the proposed methodology.
      PubDate: Jan. 2016
      Issue No: Vol. 7, No. 1 (2016)
       
  • A Three-Phase Grid Tied SPV System With Adaptive DC Link Voltage for CPI
           Voltage Variations
    • Authors: Jain; C.;Singh, B.;
      Pages: 337 - 344
      Abstract: This paper deals with a three-phase two-stage grid tied SPV (solar photo-voltaic) system. The first stage is a boost converter, which serves the purpose of MPPT (maximum power point tracking) and feeding the extracted solar energy to the DC link of the PV inverter, whereas the second stage is a two-level VSC (voltage source converter) serving as PV inverter which feeds power from a boost converter into the grid. The proposed system uses an adaptive DC link voltage which is made adaptive by adjusting reference DC link voltage according to CPI (common point of interconnection) voltage. The adaptive DC link voltage control helps in the reduction of switching power losses. A feed forward term for solar contribution is used to improve the dynamic response. The system is tested considering realistic grid voltage variations for under voltage and over voltage. The performance improvement is verified experimentally. The proposed system is advantageous not only in cases of frequent and sustained under voltage (as in the cases of far radial ends of Indian grid) but also in case of normal voltages at CPI. The THD (total harmonics distortion) of grid current has been found well under the limit of an IEEE-519 standard.
      PubDate: Jan. 2016
      Issue No: Vol. 7, No. 1 (2016)
       
  • Design and Implementation of Type-2 Fuzzy Logic Controller for DFIG-Based
           Wind Energy Systems in Distribution Networks
    • Authors: Krishnama Raju; S.;Pillai, G.N.;
      Pages: 345 - 353
      Abstract: Handling the uncertainties in the wind speed and the grid disturbances is a major challenge to the DFIGs to fulfill the modern grid code requirements. This paper proposes the design and implementation of a novel control strategy using interval type-2 fuzzy sets for grid integration of doubly fed induction generator (DFIG) based wind turbines. The presence of third dimension in the type-2 membership function offers an additional degree of freedom in the design of the proposed controller to contribute to power oscillations damping and voltage recovery following parameter uncertainties in the network. The vector control with proposed strategy for DFIG is able to handle uncertainties in the operating conditions of the distributed network like faults, load changes, and wind speed. The performance of the controller is evaluated by connecting the wind turbine to IEEE 34-bus test system considering the various uncertainties. The real time simulations are carried out using real time digital simulator (RTDS) with hardware in loop (HIL) configuration to support the feasibility of the controller for real time applications.
      PubDate: Jan. 2016
      Issue No: Vol. 7, No. 1 (2016)
       
  • An Analysis of the Effects and Dependency of Wind Power Penetration on
           System Frequency Regulation
    • Authors: Nga Nguyen;Mitra; J.;
      Pages: 354 - 363
      Abstract: The integration of renewable energy sources into power systems has gathered significant momentum globally because of its unlimited supply and environmental benefits. Within the portfolio of renewable energy, wind power is expected to have a soaring growth rate in the coming years. Despite its well known benefits, wind power poses several challenges in grid integration. The inherent intermittent and non-dispatchable features of wind power not only inject additional fluctuations to the already variable nature of frequency deviation, they also decrease frequency stability by reducing the inertia and the regulation capability. This paper closely examines these effects as well as the effect on tie-line flows and area control error, which causes a larger and longer frequency deviation in the integrated system. Further, the effect of wind power on frequency regulation capability at different penetration levels is also examined. The analytical and simulation results presented here provide some guidance on determining maximum wind power penetration level given a frequency deviation limit.
      PubDate: Jan. 2016
      Issue No: Vol. 7, No. 1 (2016)
       
  • Coordinated Operation and Control of VSC Based Multiterminal High Voltage
           DC Transmission Systems
    • Authors: Raza; A.;Xu Dianguo;Liu Yuchao;Su Xunwen;Williams, B.W.;Cecati, C.;
      Pages: 364 - 373
      Abstract: This paper deals with a multiterminal voltage source converter (VSC)-based high voltage dc transmission system (M-HVDC) connecting offshore wind farms to onshore ac grids. Three M-HVDC configurations studied, each with different control strategies. The voltage-current characteristics of VSCs are presented and VSC converter operation with different output powers from offshore wind farms is assessed. A generalized droop control strategy is mainly used to realize autonomous coordination among converters without the need of communication. Operation of the three configurations with respect to their control system is analyzed through PSCAD/EMTDC simulations and experimentation. Results show control performance during wind power change, eventual permanent VSC disconnection, and change in power demand from the ac grid side converter.
      PubDate: Jan. 2016
      Issue No: Vol. 7, No. 1 (2016)
       
  • A Game Theoretic Approach to Risk-Based Optimal Bidding Strategies for
           Electric Vehicle Aggregators in Electricity Markets With Variable Wind
           Energy Resources
    • Authors: Hongyu Wu;Shahidehpour; M.;Alabdulwahab, A.;Abusorrah, A.;
      Pages: 374 - 385
      Abstract: This paper proposes a stochastic optimization model for optimal bidding strategies of electric vehicle (EV) aggregators in day-ahead energy and ancillary services markets with variable wind energy. The forecast errors of EV fleet characteristics, hourly loads, and wind energy as well as random outages of generating units and transmission lines are considered as potential uncertainties, which are represented by scenarios in the Monte Carlo Simulation (MCS). The conditional value at risk (CVaR) index is utilized for measuring EV aggregators risks caused by the uncertainties. The EV aggregators optimal bidding strategy is formulated as a mathematical programming with equilibrium constraints (MPEC), in which the upper level problem is the aggregators CVaR maximization while the lower level problem corresponds to the system operation cost minimization. The bi-level problem is transformed into a single-level mixed integer linear programming (MILP) problem using the prime-dual formulation with linearized constraints. The progressive hedging algorithm (PHA) is utilized to solve the resulting single-level MILP problem. A game theoretic approach is developed for analyzing the competition among the EV aggregators. Numerical cases are studied for a modified 6-bus system and the IEEE 118-bus system. The results show the validity of the proposed approach and the impact of the aggregators bidding strategies on the stochastic electricity market operation.
      PubDate: Jan. 2016
      Issue No: Vol. 7, No. 1 (2016)
       
  • Table of contents
    • Pages: 387 - 387
      Abstract: Presents the table of contents for this issue of the periodical.
      PubDate: Jan. 2016
      Issue No: Vol. 7, No. 1 (2016)
       
  • Guest Editorial: Special Section on Offshore Energy From the Tides and
           Waves: Technologies, Conversions, Grid Interface, and Control
    • Authors: Benbouzid; M.;
      Pages: 389 - 389
      Abstract: This special section contains six papers on offshore energy from the tides and waves.
      PubDate: Jan. 2016
      Issue No: Vol. 7, No. 1 (2016)
       
  • Evaluation of Electromechanical Systems Dynamically Emulating a Candidate
           Hydrokinetic Turbine
    • Authors: Cavagnaro; R.J.;Neely, J.C.;Fay, F.-X.;Lopez Mendia, J.;Rea, J.A.;
      Pages: 390 - 399
      Abstract: Implications of conducting hardware-in-the-loop testing of a specific hydrokinetic turbine on controllable motor-generator sets or electromechanical emulation machines (EEMs)are explored. The emulator control dynamic equations are presented, methods for scaling turbine parameters are developed and evaluated, and experimental results are presented from three EEMs programmed to emulate the same vertical-axis fixed-pitch turbine. Although hardware platforms and control implementations varied, results show that each EEM is successful in emulating the turbine model at different power levels, thus demonstrating the general feasibility of the approach. However, performance of motor control under torque command, current command, or speed command differed. In a demonstration of the intended use of an EEM for evaluating a hydrokinetic turbine implementation, a power takeoff controller tracks the maximum power-point of the turbine in response to turbulence. Utilizing realistic inflow conditions and control laws, the emulator dynamic speed response is shown to agree well at low frequencies with numerical simulation but to deviate at high frequencies.
      PubDate: Jan. 2016
      Issue No: Vol. 7, No. 1 (2016)
       
  • Filter Design for Cable Overvoltage and Power Loss Minimization in a Tidal
           Energy System With Onshore Converters
    • Authors: Sousounis; M.C.;Shek, J.K.H.;Mueller, M.A.;
      Pages: 400 - 408
      Abstract: By moving the back-to-back ac-dc-ac converters in a tidal current conversion system (TCCS) onshore, maintenance requirements and cost are reduced significantly. This is because underwater components are not easily accessible and operate in a harsh environment. In addition to increased maintainability, the concept of long-distance controls offers maximum power capture from the tidal currents in the same way that a converter in the nacelle would offer. However, a number of challenges are associated with the concept of controlling electrical machines through long cables, which include electromagnetic traveling waves in the cables and system resonance. These phenomena can induce overvoltages at the generator terminals which can lead to system failure and high harmonics that can induce extra power losses. The major contribution of this paper is a new method of filter design for systems with long-distance controls and for minimization of system power loss. The proposed method is validated by developing a full resource-to-grid TCCS in MATLAB/Simulink. Simulation results show that using the proposed method, overvoltage mitigation can be achieved in the same way as literature-based filters, but at the same time, minimize the total system losses. The results from the analysis can be used to optimize tidal energy conversion systems with a similar electrical configuration.
      PubDate: Jan. 2016
      Issue No: Vol. 7, No. 1 (2016)
       
  • Modeling and Vector Control of Marine Current Energy Conversion System
           Based on Doubly Salient Permanent Magnet Generator
    • Authors: Hao Chen;Ait-Ahmed; N.;Machmoum, M.;Zaim, M.E.-H.;
      Pages: 409 - 418
      Abstract: This paper provides a model and a control of a marine current energy conversion system. The modeled marine current energy conversion system is a 10-kW generating system with a low-speed doubly salient permanent magnet generator of 50rpm. First, the resource, the turbine, and a dynamic analytical model of the generator are developed. Second, due to variations of marine current speed, which may lead to strong fluctuations in the power extracted by the marine current turbine, control strategies for the marine current energy conversion system at both low and high marine current speeds are analyzed, assessed, and compared. Finally, simulations of the proposed system are carried out, modeled, and simulated on MATLAB/Simulink software.
      PubDate: Jan. 2016
      Issue No: Vol. 7, No. 1 (2016)
       
  • On the Sensitivity of Optimal Wave Energy Device Geometry to the Energy
           Maximizing Control System
    • Authors: Garcia-Rosa; P.B.;Ringwood, J.V.;
      Pages: 419 - 426
      Abstract: Wave energy converters (WECs) are traditionally designed independently of control systems. This usually involves matching the device frequency response to the predominant sea spectrum of a specific site. Energy maximizing control systems are subsequently employed to improve the energy conversion of the device for sea states other than the design sea state. It is well known that some control techniques have the ability to change the characteristics of a wave energy device, allowing it to improve the power absorption for frequencies other than the device natural frequency. However, while the controllers do their best to broaden the device frequency response, they can be limited in their capability to produce an overall optimal system. A different approach is studied in this paper, where iteration is performed between geometry optimization and control design. The aim is to investigate the implications of geometry optimization in the absence of control and the ultimate effect of incorporating the control design at the geometry optimization stage. Unconstrained control strategies are considered, namely, latching, declutching, and a model predictive control-like algorithm. It is shown that different optimal WEC geometries can be obtained depending on whether the device is controlled or not and the type of controller employed. The differences in overall power absorption characteristics of the optimized geometries are presented.
      PubDate: Jan. 2016
      Issue No: Vol. 7, No. 1 (2016)
       
  • Improvements in the Reactive Control and Latching Control Strategies Under
           Maximum Excursion Constraints Using Short-Time Forecast
    • Authors: Andres Montoya Andrade; D.-E.;de la Villa Jaen, A.;Garcia Santana, A.;
      Pages: 427 - 435
      Abstract: Control strategies are essential for the proper functioning of point absorbers. One of them is reactive control, which requires the system to work as a motor during part of the wave cycle and typically places stringent requirements on the efficiency of the power take-off (PTO) machinery. On the other hand, latching control consists of locking the oscillator into position in an intermittent and timely fashion to improve performance over linear damping. This way, the PTO system always works as a generator. This paper proposes latching and reactive control strategies in irregular waves considering short-term predictions on the oscillating system performance. If it is predicted that the end-strokes are going to be reached by the oscillating system, then the damping coefficient will be calculated in order to extract energy so that the velocity vanishes when the end-strokes are reached. The power absorbed by the PTO system significantly increases when the proposed control strategies are applied. Moreover, the oscillating system velocities decrease and the peak-to-average power ratios present acceptable values. The formulation of the proposed methods are presented as well as numerical simulations in regular and irregular waves.
      PubDate: Jan. 2016
      Issue No: Vol. 7, No. 1 (2016)
       
  • Thermal Rating of a Submerged Substation for Wave Power
    • Authors: Baudoin; A.;Bostrom, C.;Leijon, M.;
      Pages: 436 - 445
      Abstract: The costs of offshore maintenance operations put high reliability-requirements on offshore equipment for ocean energy, especially on submerged ones. Thermal management is thus essential in the design of the prototypes of a marine substation, developed at Uppsala University, for grid interface of wave power parks. The cooling system itself should be efficient as well as reliable. Therefore, the feasibility of a completely passive cooling strategy was evaluated. The studied substation includes various power components, which dissipate heat and are installed in one pressurized vessel. Thermal cross-coupling was investigated with 3-D submodels and a thermal network model. An electric circuit was coupled to determine the rated power of the substation. The results depend mainly on the dc-voltage, the seawater temperature, and the thermal contact between the components and the hull.
      PubDate: Jan. 2016
      Issue No: Vol. 7, No. 1 (2016)
       
  • IEEE PES Resource Center
    • Pages: 446 - 446
      Abstract: Advertisement, IEEE.
      PubDate: Jan. 2016
      Issue No: Vol. 7, No. 1 (2016)
       
  • Scholarship Plus Initiative
    • Pages: 447 - 447
      Abstract: Advertisement, IEEE.
      PubDate: Jan. 2016
      Issue No: Vol. 7, No. 1 (2016)
       
  • The power of information
    • Pages: 448 - 448
      Abstract: Advertisement, IEEE.
      PubDate: Jan. 2016
      Issue No: Vol. 7, No. 1 (2016)
       
 
 
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