The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Nikos D. Hatziargyriou - One of the best experts on this subject based on the ideXlab platform.
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optimal control of variable speed wind turbines in Islanded Mode of operation
IEEE Transactions on Energy Conversion, 2010Co-Authors: F D Kanellos, Nikos D. HatziargyriouAbstract:Nowadays, technology evolution and deregulation of the electric utility industry enable distributed generation (DG) to play an increasing role in satisfying locally the power demand. In this paper, an optimal control method for variable speed wind turbines (VSWTs) in Islanded Mode of operation is presented. Aim of this control system is to minimize the necessary control action in order to track the active power demand. Consequently, reduced mechanical stresses and equipment damages are achieved, while system stable operation and reliability are ensured. The proposed control scheme can be applied to any type of pitch controlled VSWT. For evaluation purposes, it is applied to a VSWT equipped with a doubly fed induction generator. Finally, simulation results are presented and general conclusions are drawn.
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control of variable speed wind turbines equipped with synchronous or doubly fed induction generators supplying Islanded power systems
Iet Renewable Power Generation, 2009Co-Authors: F D Kanellos, Nikos D. HatziargyriouAbstract:A control method for variable speed wind turbines (VSWTs) supplying Islanded parts of electrical networks is presented. Active power/frequency and reactive power/voltage droops are applied in order to determine the active, reactive power production, thus downscaling to the VSWTs the conventional control concepts of the power plants. Two types of VSWTs comprising doubly fed induction generators or synchronous generators are considered. Electrical, aerodynamic and structural detailed dynamic Models were developed and combined with the proposed control strategies ensuring fast regulation of the frequency and the voltage in the Islanded Mode of operation. The obtained Models are used for the simulation of a representative simplified distribution network supplied by VSWTs.
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control of variable speed wind turbines in Islanded Mode of operation
IEEE Transactions on Energy Conversion, 2008Co-Authors: F D Kanellos, Nikos D. HatziargyriouAbstract:Nowadays, technology evolution and deregulation of the electric utility industry enable distributed generation (DG) to play an increasing role in locally satisfying the expanding power demand. In this paper, the Islanded operation of an electrical grid supplied by wind turbines, which belong to the most rapidly expanding DG technologies, is studied. Control strategies for power electronics interface of variable speed wind turbines, ensuring fast control of frequency and voltage, are proposed.
Bhim Singh - One of the best experts on this subject based on the ideXlab platform.
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robust control for Islanded and seamless Mode switching of wind pv grid tied generation system
IEEE Transactions on Industry Applications, 2021Co-Authors: Seema Kewat, Bhim SinghAbstract:This paper deals with robust control strategy for a distributed generation system (DGS), which operates in both Islanded and grid-connected Modes. Generally, in the low-voltage Islanded Mode of DGS, the PCC (Point of Common Coupling) voltages are unbalanced due to the unbalanced load connection. Therefore, in an Islanded Mode of DGS, the LSC is controlled using the IPR (Improved Proportional Resonant) controller to maintain the PCC voltages quality within the IEEE-1547 standard. Moreover, the DGS is capable to synchronize to the grid without any transient current. During the change of Modes of DGS, large transients occur in the battery current due to the switching of battery control. This problem is resolved by the presented bidirectional DC-DC converter control strategy and robust ILQSOGI (Inner Loop Quadrature Second Order Generalized Integrator) based PLL. The effectiveness of this DGS control strategy is verified by the corresponding MATLAB/Simulink platform under load unbalance, solar irradiance changes and during Mode of switching. Moreover, the simulation results are validated using the test results and show the robustness of the control strategy during abnormal grid voltage condition.
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Performance Enhancement of PV–DG–BS Distributed Generation System in Islanded Mode
Journal of The Institution of Engineers (India): Series B, 2020Co-Authors: Shatakshi Jha, Bhim Singh, Sukumar MishraAbstract:The photovoltaic (PV)-based distributed generation systems are being promoted for electrification of remote and hilly areas. In the absence of grid, the continuity, quality, and reliability of the power supply need to be regulated through deployment of auxiliary generators, energy storage systems, etc., which is the focus area of this work. The aim of this paper is to address multiple challenges of power management, power quality, maximum energy harvesting from renewable source, battery current control, and load balancing in a diesel generator (DG)–photovoltaic (PV)–battery energy storage (BES)-based standalone system, with reduced number of converters. A voltage source converter (VSC) is used for implementing a modified system identification technique of normalized robust mixed norm (NRMN), which is found better for improving the power quality index as compared to the conventional methods. Further, the given VSC control scheme also achieves balancing of DG currents in case of unbalanced load and coordinates the power obtained from PV array, and DG, to feed the loads at all times. The PV array is connected in single-stage manner, i.e., without interlinking DC–DC converter, for making the system economic and efficient. The function of MPPT operation of PV array, thus, is achieved here through the buck-boost converter (BBC) which is a bidirectional converter connected between BES and the DC side of VSC. The BBC control scheme in this paper is unified with the battery current control to regulate the battery charging/discharging current within permissible limits. The robustness of control is successfully tested in the laboratory for various scenarios on an experimental prototype.
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robust control for Islanded and seamless Mode switching of wind pv grid tied generation system
European Conference on Cognitive Ergonomics, 2019Co-Authors: Bhim SinghAbstract:This paper deals with a robust control strategy for distributed generation system (DGS), which operates in both Islanded and grid-connected Modes. In Islanded Mode, the load side VSC (Voltage Source Converter) is controlled using the PR (Proportional Resonant) controller, thereby the CCP (Common Coupling Point) voltage quality is maintained within the IEEE-1547 standard. Moreover, the DGS is capable to synchronize to the grid without any transient current. In grid connected Mode, the load side VSC switching is provided using the inner-loop SOGI based control algorithm. Generally during the Mode change from standalone Mode to grid connected Mode and vice versa, large transients occur in the battery current due to the switching. This problem is resolved by proposed bidirectional DC-DC converter control strategy and robust inner-loop SOGI based PLL. The proposed control strategies in DGS, provide smooth Mode transition from the grid connected Mode to an Islanded Mode and vice versa, thereby the reliability of the DGS is enhanced. The proposed DGS is validated on the experimental prototype of DGS.
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multi objective control algorithm for small hydro and spv generation based dual Mode reconfigurable system
IEEE Transactions on Smart Grid, 2018Co-Authors: Mahendra K Reddy, Bhim SinghAbstract:This paper proposes a small hydro (ac) and solar photo-voltaic (SPV) generation (dc)-based dual Mode multi-functional reconfigurable system. The small hydro system is connected to the point of common coupling (PCC) directly. The SPV system is connected to ac side (PCC) through a boost converter and a voltage source converter (VSC). A storage system is integrated across dc link of VSC through a bidirectional converter to balance the generation and the loads in an Islanded Mode. The distinguished feature of proposed system is that it operates either in grid connected Mode or an Islanded Mode depending on grid availability. It supplies uninterruptable power to emergency loads. An important aspect of control strategy is that it automatically synchronizes the system to the grid when the grid is available in an Islanded Mode. It also disconnects the system from the grid when a fault occurs on the grid feeder in grid connected Mode. In an Islanded Mode, it regulates voltage and frequency of hydro generator across PCC. In grid connected Mode, it regulates the current fed by VSC. It also improves the power quality of the hydro generator and the grid by elimination of current harmonics, load balancing, and compensation of reactive power under nonlinear loads. The performance of proposed system is found satisfactory in transient Modes and in dynamic conditions. The interruption time in the load end voltage and resynchronization time are well within an IEEE 1547 standard. The total harmonic distortion of grid current, hydro generator current and load voltage is also well under IEEE 519 standard even at nonlinear loads.
F D Kanellos - One of the best experts on this subject based on the ideXlab platform.
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optimal control of variable speed wind turbines in Islanded Mode of operation
IEEE Transactions on Energy Conversion, 2010Co-Authors: F D Kanellos, Nikos D. HatziargyriouAbstract:Nowadays, technology evolution and deregulation of the electric utility industry enable distributed generation (DG) to play an increasing role in satisfying locally the power demand. In this paper, an optimal control method for variable speed wind turbines (VSWTs) in Islanded Mode of operation is presented. Aim of this control system is to minimize the necessary control action in order to track the active power demand. Consequently, reduced mechanical stresses and equipment damages are achieved, while system stable operation and reliability are ensured. The proposed control scheme can be applied to any type of pitch controlled VSWT. For evaluation purposes, it is applied to a VSWT equipped with a doubly fed induction generator. Finally, simulation results are presented and general conclusions are drawn.
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control of variable speed wind turbines equipped with synchronous or doubly fed induction generators supplying Islanded power systems
Iet Renewable Power Generation, 2009Co-Authors: F D Kanellos, Nikos D. HatziargyriouAbstract:A control method for variable speed wind turbines (VSWTs) supplying Islanded parts of electrical networks is presented. Active power/frequency and reactive power/voltage droops are applied in order to determine the active, reactive power production, thus downscaling to the VSWTs the conventional control concepts of the power plants. Two types of VSWTs comprising doubly fed induction generators or synchronous generators are considered. Electrical, aerodynamic and structural detailed dynamic Models were developed and combined with the proposed control strategies ensuring fast regulation of the frequency and the voltage in the Islanded Mode of operation. The obtained Models are used for the simulation of a representative simplified distribution network supplied by VSWTs.
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control of variable speed wind turbines in Islanded Mode of operation
IEEE Transactions on Energy Conversion, 2008Co-Authors: F D Kanellos, Nikos D. HatziargyriouAbstract:Nowadays, technology evolution and deregulation of the electric utility industry enable distributed generation (DG) to play an increasing role in locally satisfying the expanding power demand. In this paper, the Islanded operation of an electrical grid supplied by wind turbines, which belong to the most rapidly expanding DG technologies, is studied. Control strategies for power electronics interface of variable speed wind turbines, ensuring fast control of frequency and voltage, are proposed.
Josep M Guerrero - One of the best experts on this subject based on the ideXlab platform.
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a linear quadratic regulator with optimal reference tracking for three phase inverter based Islanded microgrids
IEEE Transactions on Power Electronics, 2021Co-Authors: Juan F Patarroyomontenegro, Fabio Andrade, Josep M Guerrero, Juan C. VasquezAbstract:This article proposes a power sharing control method based on the linear quadratic regulator with optimal reference tracking (LQR-ORT) for three-phase inverter-based generators using inductor-capacitor-inductor (LCL) filters Islanded Mode. Compared to single-input single-output (SISO)-based controllers, the LQR-ORT controller increases robustness margins and reduces the quadratic value of the power error and control inputs during transient response. Supplementary loops are used to reduce frequency and voltage deviations in the ac bus without communications. The supplementary loop for voltage regulation is based on the droop controller by reducing direct and quadrature output voltages according to the active and reactive power demand. A Model in a synchronous reference frame that integrates power sharing and voltage–current dynamics is also proposed. In addition, a methodology to develop an Islanded microgrid Model in a synchronous reference frame is proposed. Robustness analysis demonstrates stability of the LQR-ORT controller under variations in the frequency and the LCL filter components. Experimental results demonstrate accuracy of the proposed Model and the effectiveness of the LQR-ORT controller on improving transient response and robustness in Islanded Mode.
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seamless transition of microgrids operation from grid connected to Islanded Mode
IEEE Transactions on Smart Grid, 2020Co-Authors: M Ganjianaboukheili, Majid Shahabi, Qobad Shafiee, Josep M GuerreroAbstract:One of the main features of Microgrids is the ability to operate in both grid-connected Mode and islanding Mode. In each Mode of operation, distributed energy resources (DERs) can be operated under grid-forming or grid-following control strategies. In grid-connected Mode, DERs usually work under grid-following control strategy, while at least one of the DERs must operate in grid-forming strategy in islanding Mode. A microgrid may experience remarkable fluctuations in voltage and current due to an unintentional islanding event. To achieve a smooth transition to islanding Mode and mitigate disturbance effect, this paper proposes a control strategy includes a) a linear voltage controller with capacitor current feedback as an input to the voltage controller and output current feedforward as an input to current controller, and b) modified droop control to emulate the inertia response of a synchronous generator. The proposed controller can suppress voltage, current and frequency fluctuations and also guarantee a smooth transition. A small signal analysis of the proposed control strategy is developed to design its coefficients as well as the destabilizing effect of constant power load (CPL). Experimental results are provided to verify the effectiveness of the proposed control strategy.
Yonggang Peng - One of the best experts on this subject based on the ideXlab platform.
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a decentralized coordination control method for parallel bidirectional power converters in a hybrid ac dc microgrid
IEEE Transactions on Industrial Electronics, 2018Co-Authors: Pengcheng Yang, Yanghong Xia, Wei Wei, Yonggang PengAbstract:In the hybrid ac–dc microgrid, the ac and dc subgrids are connected by bidirectional power converters (BPCs) that play an important role in the load power sharing and power interaction between the ac and dc subgrids. The coordination control and circulating current suppression for the parallel BPC system are very challenging. In this paper, a decentralized coordination control method is proposed for parallel three-phase BPCs, which can suppress the circulating currents, realize proper power interaction, and achieve overall load power sharing in both the grid-connected Mode and the Islanded Mode. The performance of the proposed control methods is verified by the real-time hardware-in-loop tests.
