The Experts below are selected from a list of 345 Experts worldwide ranked by ideXlab platform
Josep M Guerrero - One of the best experts on this subject based on the ideXlab platform.
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a unified Voltage Harmonic control strategy for coordinated compensation with vcm and ccm converters
IEEE Transactions on Power Electronics, 2018Co-Authors: Xin Zhao, Lexuan Meng, Chuan Xie, Josep M GuerreroAbstract:Harmonics have been considered as one of the major issues in modern power grids. Considering the high penetration level of power electronic converter interfaced distributed generation (DG) units, it is of interest to provide ancillary services through DG interfacing converters, such as Harmonic compensation. In that case, multiple DG interfacing converters are utilized to compensate Harmonics, and the compensation effort should be properly shared among these converters. However, it is rarely considered in existing literatures that converters operating in different modes, such as Voltage-controlled mode (VCM) and current-controlled mode (CCM), need to cooperatively provide the compensation function. Aiming at this objective, this paper proposes a unified Voltage Harmonic mitigation strategy for VCM and CCM converters with high Harmonic current sharing accuracy. Another advantage of the proposal is that the grid-side and load-side current measurements are avoided, which reduces the implementation cost. Experimental results are presented to demonstrate the effectiveness of the method.
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a Voltage feedback based Harmonic compensation strategy for current controlled converters
IEEE Transactions on Industry Applications, 2018Co-Authors: Xin Zhao, Josep M Guerrero, Juan C. Vasquez, Lexuan Meng, Chuan Xie, Mehdi SavaghebiAbstract:Harmonics have been considered as one of the major issues in future power grids. With the increasing demand in advanced control functions, power electronic converter interfaced distributed generators (DGs) are expected to perform Harmonic compensation when necessary. It has been demonstrated in a number of studies that DG converters operating in Voltage-controlled mode can be easily configured to realize Voltage Harmonic compensation utilizing naturally embedded Voltage control loop. While for DGs operating in current-controlled mode (CCM), such function was rarely studied. Considering that CCM is commonly used in renewable energy based generators and energy storage systems, it has certain significance to achieve the same function with CCM converters. Aiming at such objectives, this paper proposes a Voltage detection based Harmonic compensator (HC) for CCM converters. The novelty and main advantages of the proposed method include the following. It realizes seamless interface of HC with inner fundamental current control loop. Compared with a conventional active power filtering method, it does not require remote load Harmonic current measurement since it is local Voltage detection based. Compared with a conventional Voltage detection based method, it offers better performance because of directly Harmonic Voltage regulation. Experimental results are presented to demonstrate the effectiveness of the method.
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an embedded Voltage Harmonic compensation strategy for current controlled dg interfacing converters
European Conference on Cognitive Ergonomics, 2016Co-Authors: Xin Zhao, Mehdi Savaghebi, Josep M Guerrero, Juan C. Vasquez, Lexuan Meng, Chuan XieAbstract:Harmonics have been considered as one of the major issues in future power grids. With the increasing demand in advanced control functions, power electronic converter interfaced Distributed Generators (DGs) are expected to perform Harmonic compensation when necessary. It has been demonstrated in a number of studies that DG converters operating in Voltage-Controlled Mode (VCM) can be easily configured to realize Voltage Harmonic suppression utilizing naturally embedded Voltage control loop. While for DG converters operating in Current-Controlled Mode (CCM), such function was rarely studied. Considering that CCM is commonly used in renewable energy based generators and energy storage systems, it has certain significance to achieve the same function with CCM operated converters. Aiming at such objective, this paper proposes a Voltage detection based embedded Harmonic Compensator (HC) for CCM converters. The novelty and main advantages of the proposed method include: 1) it realizes seamless interface of HC with inner fundamental current control loop; 2) compared with conventional active power filtering method, it does not require remote load Harmonic current measurement since it is based on local Voltage detection; 3) compared with conventional Voltage detection based method, it offers better performance because of direct Harmonic Voltage regulation. Experimental results are presented to demonstrate the effectiveness of the method.
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virtual admittance loop for Voltage Harmonic compensation in microgrids
IEEE Transactions on Industry Applications, 2016Co-Authors: Cristian Blanco, Josep M Guerrero, Juan C. Vasquez, David Reigosa, Fernando BrizAbstract:The use of the virtual admittance concept for Harmonic and/or unbalance compensation in microgrids when multiple inverters operate in parallel is proposed in this paper. The virtual impedance concept has been traditionally used for these purposes. However, one drawback of the virtual impedance is that it can only be applied to distributed generation (DG) units operating in Voltage control mode (VSI-VCM), but is not applicable to DG units working in current control mode (e.g., current-regulated Voltage-source inverters, VSI-CCM). Contrary to this, the proposed method can be used in any converter topology and control mode, including VSI-CCM and VSI-VCM.
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Voltage unbalance and Harmonic compensation in microgrids by cooperation of distributed generators and active power filters
The Power Electronics Drive Systems & Technologies Conference, 2016Co-Authors: Mohammad M Hashempour, Mehdi Savaghebi, Juan C. Vasquez, Josep M GuerreroAbstract:In this paper, the power quality of microgrids is addressed. To achieve the desired level of power quality, a strategy based on the coordinated control between DGs and APFs is proposed. In this regard, hierarchical control is applied where primary control consists of power droop controller of DGs, selective virtual impedance and Voltage/current regulators. Based on the secondary control, at first Voltage Harmonic compensation and Voltage unbalance compensation of point of common coupling (PCC), that might includes sensitive loads, is carried out by DGs. Voltage compensation of PCC by DGs may cause severe Voltage distortion at DGs terminals. Thus, the coordinated control is used to mitigate the Voltage distortion to the defined maximum allowable value at DGs terminals. Evaluation of the proposed hierarchical control is carried out by a simulation study.
Juan C. Vasquez - One of the best experts on this subject based on the ideXlab platform.
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a Voltage feedback based Harmonic compensation strategy for current controlled converters
IEEE Transactions on Industry Applications, 2018Co-Authors: Xin Zhao, Josep M Guerrero, Juan C. Vasquez, Lexuan Meng, Chuan Xie, Mehdi SavaghebiAbstract:Harmonics have been considered as one of the major issues in future power grids. With the increasing demand in advanced control functions, power electronic converter interfaced distributed generators (DGs) are expected to perform Harmonic compensation when necessary. It has been demonstrated in a number of studies that DG converters operating in Voltage-controlled mode can be easily configured to realize Voltage Harmonic compensation utilizing naturally embedded Voltage control loop. While for DGs operating in current-controlled mode (CCM), such function was rarely studied. Considering that CCM is commonly used in renewable energy based generators and energy storage systems, it has certain significance to achieve the same function with CCM converters. Aiming at such objectives, this paper proposes a Voltage detection based Harmonic compensator (HC) for CCM converters. The novelty and main advantages of the proposed method include the following. It realizes seamless interface of HC with inner fundamental current control loop. Compared with a conventional active power filtering method, it does not require remote load Harmonic current measurement since it is local Voltage detection based. Compared with a conventional Voltage detection based method, it offers better performance because of directly Harmonic Voltage regulation. Experimental results are presented to demonstrate the effectiveness of the method.
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an embedded Voltage Harmonic compensation strategy for current controlled dg interfacing converters
European Conference on Cognitive Ergonomics, 2016Co-Authors: Xin Zhao, Mehdi Savaghebi, Josep M Guerrero, Juan C. Vasquez, Lexuan Meng, Chuan XieAbstract:Harmonics have been considered as one of the major issues in future power grids. With the increasing demand in advanced control functions, power electronic converter interfaced Distributed Generators (DGs) are expected to perform Harmonic compensation when necessary. It has been demonstrated in a number of studies that DG converters operating in Voltage-Controlled Mode (VCM) can be easily configured to realize Voltage Harmonic suppression utilizing naturally embedded Voltage control loop. While for DG converters operating in Current-Controlled Mode (CCM), such function was rarely studied. Considering that CCM is commonly used in renewable energy based generators and energy storage systems, it has certain significance to achieve the same function with CCM operated converters. Aiming at such objective, this paper proposes a Voltage detection based embedded Harmonic Compensator (HC) for CCM converters. The novelty and main advantages of the proposed method include: 1) it realizes seamless interface of HC with inner fundamental current control loop; 2) compared with conventional active power filtering method, it does not require remote load Harmonic current measurement since it is based on local Voltage detection; 3) compared with conventional Voltage detection based method, it offers better performance because of direct Harmonic Voltage regulation. Experimental results are presented to demonstrate the effectiveness of the method.
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virtual admittance loop for Voltage Harmonic compensation in microgrids
IEEE Transactions on Industry Applications, 2016Co-Authors: Cristian Blanco, Josep M Guerrero, Juan C. Vasquez, David Reigosa, Fernando BrizAbstract:The use of the virtual admittance concept for Harmonic and/or unbalance compensation in microgrids when multiple inverters operate in parallel is proposed in this paper. The virtual impedance concept has been traditionally used for these purposes. However, one drawback of the virtual impedance is that it can only be applied to distributed generation (DG) units operating in Voltage control mode (VSI-VCM), but is not applicable to DG units working in current control mode (e.g., current-regulated Voltage-source inverters, VSI-CCM). Contrary to this, the proposed method can be used in any converter topology and control mode, including VSI-CCM and VSI-VCM.
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Voltage unbalance and Harmonic compensation in microgrids by cooperation of distributed generators and active power filters
The Power Electronics Drive Systems & Technologies Conference, 2016Co-Authors: Mohammad M Hashempour, Mehdi Savaghebi, Juan C. Vasquez, Josep M GuerreroAbstract:In this paper, the power quality of microgrids is addressed. To achieve the desired level of power quality, a strategy based on the coordinated control between DGs and APFs is proposed. In this regard, hierarchical control is applied where primary control consists of power droop controller of DGs, selective virtual impedance and Voltage/current regulators. Based on the secondary control, at first Voltage Harmonic compensation and Voltage unbalance compensation of point of common coupling (PCC), that might includes sensitive loads, is carried out by DGs. Voltage compensation of PCC by DGs may cause severe Voltage distortion at DGs terminals. Thus, the coordinated control is used to mitigate the Voltage distortion to the defined maximum allowable value at DGs terminals. Evaluation of the proposed hierarchical control is carried out by a simulation study.
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virtual admittance loop for Voltage Harmonic compensation in microgrids
European Conference on Cognitive Ergonomics, 2015Co-Authors: Cristian Blanco, Josep M Guerrero, Juan C. Vasquez, David Reigosa, Fernando BrizAbstract:The use of the virtual admittance concept for Harmonic and/or unbalance compensation in microgrids when multiple inverters operate in parallel is proposed in this paper. The virtual impedance concept has been traditionally used for these purposes. However, one drawback of the virtual impedance is that it can only be applied to distributed generation (DG) units operating in Voltage control mode (VSI-VCM), but is not applicable to DG units working in current control mode (e.g. current regulated Voltage source inverters, VSI-CCM or current source inverters, CSIs. Contrary to this, the proposed method can be used in any converter topology and control mode, including VSI-CCM, VSI-VCM and CSI.
Suleiman M Sharkh - One of the best experts on this subject based on the ideXlab platform.
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nearest vector modulation strategies with minimum amplitude of low frequency neutral point Voltage oscillations for the neutral point clamped converter
IEEE Transactions on Power Electronics, 2013Co-Authors: Georgios I Orfanoudakis, M A Yuratich, Suleiman M SharkhAbstract:This paper investigates the problem of low-frequency Voltage oscillations that appear at the neutral point (NP) of a three-level neutral-point-clamped (NPC) converter. Starting with a detailed analysis of their origin, the paper derives the minimum amplitude of these oscillations that can be achieved by nearest-vector (NV) modulation strategies. It then proves that the criterion of the direction of dc-link capacitor imbalance, which is commonly adopted by NV strategies for performing the task of capacitor balancing, poses a barrier in achieving this minimum. A new criterion is proposed instead, together with an algorithm that incorporates it into existing NV strategies. For the case of NPC inverters operating as motor drives, the resulting reduction in the amplitude of NP Voltage oscillations ranges from 30% to 50%. The approach has the advantage of avoiding the significant increment in switching losses and output Voltage Harmonic distortion, caused by other methods. Simulations in MATLAB-Simulink are used to illustrate its operation and verify that it offers the claimed benefit.
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hybrid modulation strategies for eliminating low frequency neutral point Voltage oscillations in the neutral point clamped converter
IEEE Transactions on Power Electronics, 2013Co-Authors: Georgios I Orfanoudakis, M A Yuratich, Suleiman M SharkhAbstract:Nearest vector (NV) modulation strategies for the neutral-point-clamped converter are known to generate low-frequency neutral point (NP) Voltage oscillations. Non-NV strategies can eliminate these oscillations, but at the expense of higher switching losses and output Voltage Harmonic distortion. This letter proposes a simple way of creating hybrid strategies, as combinations of NV and non-NV strategies, which are also able to eliminate NP Voltage oscillations. The approach minimizes the participation of non-NV strategies and hence their drawbacks, while it can be applied to any type of load (nonlinear and/or unbalanced). Simulations in MATLAB-Simulink are used to illustrate its operation.
Georgios I Orfanoudakis - One of the best experts on this subject based on the ideXlab platform.
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nearest vector modulation strategies with minimum amplitude of low frequency neutral point Voltage oscillations for the neutral point clamped converter
IEEE Transactions on Power Electronics, 2013Co-Authors: Georgios I Orfanoudakis, M A Yuratich, Suleiman M SharkhAbstract:This paper investigates the problem of low-frequency Voltage oscillations that appear at the neutral point (NP) of a three-level neutral-point-clamped (NPC) converter. Starting with a detailed analysis of their origin, the paper derives the minimum amplitude of these oscillations that can be achieved by nearest-vector (NV) modulation strategies. It then proves that the criterion of the direction of dc-link capacitor imbalance, which is commonly adopted by NV strategies for performing the task of capacitor balancing, poses a barrier in achieving this minimum. A new criterion is proposed instead, together with an algorithm that incorporates it into existing NV strategies. For the case of NPC inverters operating as motor drives, the resulting reduction in the amplitude of NP Voltage oscillations ranges from 30% to 50%. The approach has the advantage of avoiding the significant increment in switching losses and output Voltage Harmonic distortion, caused by other methods. Simulations in MATLAB-Simulink are used to illustrate its operation and verify that it offers the claimed benefit.
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hybrid modulation strategies for eliminating low frequency neutral point Voltage oscillations in the neutral point clamped converter
IEEE Transactions on Power Electronics, 2013Co-Authors: Georgios I Orfanoudakis, M A Yuratich, Suleiman M SharkhAbstract:Nearest vector (NV) modulation strategies for the neutral-point-clamped converter are known to generate low-frequency neutral point (NP) Voltage oscillations. Non-NV strategies can eliminate these oscillations, but at the expense of higher switching losses and output Voltage Harmonic distortion. This letter proposes a simple way of creating hybrid strategies, as combinations of NV and non-NV strategies, which are also able to eliminate NP Voltage oscillations. The approach minimizes the participation of non-NV strategies and hence their drawbacks, while it can be applied to any type of load (nonlinear and/or unbalanced). Simulations in MATLAB-Simulink are used to illustrate its operation.
Fernando Briz - One of the best experts on this subject based on the ideXlab platform.
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design of a cooperative Voltage Harmonic compensation strategy for islanded microgrids combining virtual admittance and repetitive controller
IEEE Transactions on Industry Applications, 2019Co-Authors: Cristian Blanco, David Reigosa, Francesco Tardelli, Pericle Zanchetta, Fernando BrizAbstract:Nonlinear loads (NLLs) in three-phase systems are known to produce current Harmonics at −5, 7, −11, 13,… times the fundamental frequency. However, Harmonics of the same frequencies are induced in microgrid Voltage thereby reducing the power quality. Dedicated equipment, such as active power filters, can be used to compensate the microgrid Harmonics. Alternatively, each distributed generation (DG) unit present in the microgrid can also be used for the same. The use of the virtual admittance concept combined with a proportional integral with resonant controller (PI-RES) control structure has previously been proposed as a Harmonic compensation sharing strategy when multiple DGs operate in parallel. The drawback of this methodology is that a large number of RES controllers might be required to compensate for all the Harmonic components induced by NLLs, increasing the tuning complexity as well as the execution time. This paper proposes the combined use of virtual admittance control loop and repetitive controller (RC) for Harmonic compensation. The main advantage of the proposed method is that only one RC is required to compensate for all the Harmonic components, significantly reducing the computational burden and the design complexity. The dynamic performance of the whole system is tested under variable NLL.
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design of a cooperative Voltage Harmonic compensation strategy for islanded microgrids combining virtual admittance and repetitive controller
European Conference on Cognitive Ergonomics, 2016Co-Authors: Cristian Blanco, David Reigosa, Francesco Tardelli, Pericle Zanchetta, Fernando BrizAbstract:Non-linear loads (NLLs) in three-phase systems are known to produce current Harmonics at −5, 7, −11, 13… times the fundamental frequency; Harmonics of the same frequencies are induced in microgrid Voltage, reducing therefore the power quality. Dedicated equipment like active power filters can be used to compensate the microgrid Harmonics; alternatively, each distributed generation (DG) unit present in the microgrid can be potentially used to compensate for those Harmonics. The use of the virtual admittance concept combined with a PI-RES control structure has been recently proposed as a Harmonic compensation sharing strategy when multiple DGs operate in parallel. The drawback of this methodology is that a large number of RES controllers might be required to compensate for all Harmonic components induced by NLLs. This paper proposes the combined use of virtual admittance control loop and repetitive controller (RC) for Harmonic compensation. The main advantage of the proposed method is that only one RC is required to compensate for all the Harmonic components, significantly reducing the computational burden and the design complexity.
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virtual admittance loop for Voltage Harmonic compensation in microgrids
IEEE Transactions on Industry Applications, 2016Co-Authors: Cristian Blanco, Josep M Guerrero, Juan C. Vasquez, David Reigosa, Fernando BrizAbstract:The use of the virtual admittance concept for Harmonic and/or unbalance compensation in microgrids when multiple inverters operate in parallel is proposed in this paper. The virtual impedance concept has been traditionally used for these purposes. However, one drawback of the virtual impedance is that it can only be applied to distributed generation (DG) units operating in Voltage control mode (VSI-VCM), but is not applicable to DG units working in current control mode (e.g., current-regulated Voltage-source inverters, VSI-CCM). Contrary to this, the proposed method can be used in any converter topology and control mode, including VSI-CCM and VSI-VCM.
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virtual admittance loop for Voltage Harmonic compensation in microgrids
European Conference on Cognitive Ergonomics, 2015Co-Authors: Cristian Blanco, Josep M Guerrero, Juan C. Vasquez, David Reigosa, Fernando BrizAbstract:The use of the virtual admittance concept for Harmonic and/or unbalance compensation in microgrids when multiple inverters operate in parallel is proposed in this paper. The virtual impedance concept has been traditionally used for these purposes. However, one drawback of the virtual impedance is that it can only be applied to distributed generation (DG) units operating in Voltage control mode (VSI-VCM), but is not applicable to DG units working in current control mode (e.g. current regulated Voltage source inverters, VSI-CCM or current source inverters, CSIs. Contrary to this, the proposed method can be used in any converter topology and control mode, including VSI-CCM, VSI-VCM and CSI.
