The Experts below are selected from a list of 20355 Experts worldwide ranked by ideXlab platform
Juan C. Vasquez - One of the best experts on this subject based on the ideXlab platform.
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Centralized Control Architecture for Coordination of Distributed Renewable Generation and Energy Storage in Islanded AC Microgrids
IEEE Transactions on Power Electronics, 2017Co-Authors: Nelson L. Diaz, Adriana Carolina Luna, Juan C. VasquezAbstract:The coordinated operation of distributed energy re- sources such as storage and generation units and also loads is re- quired for the reliable operation of an islandedmicrogrid. Since in islanded microgrids the storage units are commonlyresponsible for regulating the voltage amplitude and frequency in the local power system, the coordination should consider safe operating limits for the stored energy, which prevents fast degradation or dam- age to the storage units. This paper proposes a centralized con- trol architecture, applicable for local area power systems such as a small-scale microgrid. The centralized architecture is based on three supervisory control tasks which consider: active power cur- tailment of generation for avoiding overcharge of the storage units, load shedding actions for preventing Deep Discharge of the stor- age units, and equalization of the state of charge (SoC) among distributed storage systems for avoiding uneven degradation. The proposed equalizationmethod has proved to be effective for equal- izing the SoC of distributed energy storage systems and for en- suring uniform charge/Discharge ratios regardless of differences in the capacity of the storage units. Additionally, the strategy is com- plemented with an optimal scheduling of load connection, which minimizes the connection and disconnection cycles of the loads within a time horizon of 24 h. The proposed architecture is veri- fied experimentally in a lab-scale prototype of a microgrid, which has real communication between the microgrid and the central controller.
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Fuzzy-logic-based gain-scheduling control for state-of-charge balance of distributed energy storage systems for DC microgrids
Conference Proceedings - IEEE Applied Power Electronics Conference and Exposition - APEC, 2014Co-Authors: Nelson L. Diaz, Tomislav Dragicevic, Juan C. VasquezAbstract:A microgrid is an integration of distributed energy sources, loads and energy storage systems. Indeed, energy storage systems are required in order to ensure reliability and power quality because of the intermittent nature of renewable energy sources and changes of load demand. Apart from that, the use of distributed energy storage units provides redundancy to the system and support possible increments in load consumption. In consequence, the control strategy used in the microgrid must take into account the stored energy balance between distributed energy storage units in order to avoid over-charge or Deep-Discharge in one of the energy storage units. Primary control in a microgrid is responsible for power sharing among units; and droop control is typically used in this stage. This paper proposes a modular and decentralized gain-scheduling control strategy based on fuzzy logic that ensures balanced stored energy among distributed energy storage units, as well as low voltage deviation in a DC microgrid. Hardware in the loop simulations show the performance of the proposed control strategy.
Nelson L. Diaz - One of the best experts on this subject based on the ideXlab platform.
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Centralized Control Architecture for Coordination of Distributed Renewable Generation and Energy Storage in Islanded AC Microgrids
IEEE Transactions on Power Electronics, 2017Co-Authors: Nelson L. Diaz, Adriana Carolina Luna, Juan C. VasquezAbstract:The coordinated operation of distributed energy re- sources such as storage and generation units and also loads is re- quired for the reliable operation of an islandedmicrogrid. Since in islanded microgrids the storage units are commonlyresponsible for regulating the voltage amplitude and frequency in the local power system, the coordination should consider safe operating limits for the stored energy, which prevents fast degradation or dam- age to the storage units. This paper proposes a centralized con- trol architecture, applicable for local area power systems such as a small-scale microgrid. The centralized architecture is based on three supervisory control tasks which consider: active power cur- tailment of generation for avoiding overcharge of the storage units, load shedding actions for preventing Deep Discharge of the stor- age units, and equalization of the state of charge (SoC) among distributed storage systems for avoiding uneven degradation. The proposed equalizationmethod has proved to be effective for equal- izing the SoC of distributed energy storage systems and for en- suring uniform charge/Discharge ratios regardless of differences in the capacity of the storage units. Additionally, the strategy is com- plemented with an optimal scheduling of load connection, which minimizes the connection and disconnection cycles of the loads within a time horizon of 24 h. The proposed architecture is veri- fied experimentally in a lab-scale prototype of a microgrid, which has real communication between the microgrid and the central controller.
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Fuzzy-logic-based gain-scheduling control for state-of-charge balance of distributed energy storage systems for DC microgrids
Conference Proceedings - IEEE Applied Power Electronics Conference and Exposition - APEC, 2014Co-Authors: Nelson L. Diaz, Tomislav Dragicevic, Juan C. VasquezAbstract:A microgrid is an integration of distributed energy sources, loads and energy storage systems. Indeed, energy storage systems are required in order to ensure reliability and power quality because of the intermittent nature of renewable energy sources and changes of load demand. Apart from that, the use of distributed energy storage units provides redundancy to the system and support possible increments in load consumption. In consequence, the control strategy used in the microgrid must take into account the stored energy balance between distributed energy storage units in order to avoid over-charge or Deep-Discharge in one of the energy storage units. Primary control in a microgrid is responsible for power sharing among units; and droop control is typically used in this stage. This paper proposes a modular and decentralized gain-scheduling control strategy based on fuzzy logic that ensures balanced stored energy among distributed energy storage units, as well as low voltage deviation in a DC microgrid. Hardware in the loop simulations show the performance of the proposed control strategy.
Yun Yang - One of the best experts on this subject based on the ideXlab platform.
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distribution power loss reduction of standalone dc microgrids using adaptive differential evolution based control for distributed battery systems
Energies, 2020Co-Authors: Junli Deng, Yuan Mao, Yun YangAbstract:With high penetrations of renewable energy sources (RES), distributed battery systems (DBS) are widely adopted in standalone DC microgrids to stabilize the bus voltages by balancing the active power. This paper presents an Adaptive Differential Evolution (ADE)-based hierarchical control for DBS to achieve online distribution power loss mitigation as well as bus voltage regulations in standalone DC microgrids. The hierarchical control comprises two layers, i.e., ADE for the secondary layer and local proportional-integral (PI) control for the primary layer. The secondary layer control provides the bus voltage references for the primary control by optimizing the fitness function, which contains the parameters of the bus voltage deviations and the power loss on the distribution lines. Simultaneously, the state-of-charge (SoC) of the battery packs are controlled by local controllers to prevent over-charge and Deep-Discharge. Case studies using a Real-Time Digital Simulator (RTDS) validate that the proposed ADE-based hierarchical control can effectively reduce the distribution power loss and regulate the bus voltages within the tolerances in DC microgrids.
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mitigating distribution power losses of standalone ac microgrids using particle swarm optimization control for distributed battery systems
Applied Power Electronics Conference, 2019Co-Authors: Yajie Jiang, Yun Yang, Siewchong Tan, S Y R HuiAbstract:Distributed battery systems (DBS) are widely used in microgrids to compensate imbalanced active and reactive power flows, and for stabilizing bus voltages of microgrids with a high penetration of renewable energy sources (RES). In this paper, a particle-swarm-optimization (PSO) method is adopted as the secondary control of DBS in a standalone AC microgrid. The fitness function of the PSO algorithm contains the parameters of the bus voltage deviations and the power losses on the distribution lines. Through iteration, the bus voltage deviations and the power losses on the distribution lines are reduced, simultaneously. Importantly, the State-of-Charges (SOC) of the battery packs are also being taken into consideration and the battery packs are controlled by local controllers to prevent Deep-Discharge and over-charge. Both results from Matlab simulation and Real-Time Digital Simulator (RTDS) validate the effectiveness of the proposed control scheme in concurrently reducing the distribution power losses and meeting bus voltage regulations in AC microgrids.
Wei Wang - One of the best experts on this subject based on the ideXlab platform.
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polyvinyl chloride silica nanoporous composite separator for all vanadium redox flow battery applications
Journal of The Electrochemical Society, 2013Co-Authors: Baohua Li, Vincent L Sprenkle, Wei WangAbstract:Redox flow batteries (RFBs) are capable of reversible conversion between electricity and chemical energy. Potential RFB applications resolve around mitigating the discrepancy between electricity production and consumption to improve the stability and utilization of the power infrastructure and tackling the intermittency of renewables such as photovoltaics or wind turbines to enable their reliable integration [1, 2]. Because the energy is stored in externally contained liquid electrolytes and the energy conversion reactions take place at the electrodes, RFBs hold a unique capability to separate energy and power and thus possess considerable design flexibility to meet either energy management driven or power rating oriented grid applications, which is considered to be a unparalleled advantage over conventional solid-state secondary batteries [3]. Other advantages of RFBs include fast response to load changes, high round-trip efficiency, long calender and cycle lives, safe operations, tolerance to Deep Discharge, etc. [4]. Among various flow battery chemistries, all-vanadium redox flow battery (VRB) was invented by Maria Skyllas-Kazacos at the University of New South Wales in the 1980s [5, 6] and have attracted substantial attention in both research and industrial communities today [7, 8]. A well-recognized advantage that makes VRB stands out among other redox chemistries is the reducedmore » crossover contamination ascribed to employing four different oxidation states of the same vanadium element as the two redox couples. Recently, great progress has led to remarkably improved energy density of VRB by using sulfuric-chloric mixed acid supporting electrolytes that were stable at 2.5M vanadium and had wider operational temperature window of -5~50oC [9], compared with the traditional sulfuric acid VRB system [10].« less
Junli Deng - One of the best experts on this subject based on the ideXlab platform.
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distribution power loss reduction of standalone dc microgrids using adaptive differential evolution based control for distributed battery systems
Energies, 2020Co-Authors: Junli Deng, Yuan Mao, Yun YangAbstract:With high penetrations of renewable energy sources (RES), distributed battery systems (DBS) are widely adopted in standalone DC microgrids to stabilize the bus voltages by balancing the active power. This paper presents an Adaptive Differential Evolution (ADE)-based hierarchical control for DBS to achieve online distribution power loss mitigation as well as bus voltage regulations in standalone DC microgrids. The hierarchical control comprises two layers, i.e., ADE for the secondary layer and local proportional-integral (PI) control for the primary layer. The secondary layer control provides the bus voltage references for the primary control by optimizing the fitness function, which contains the parameters of the bus voltage deviations and the power loss on the distribution lines. Simultaneously, the state-of-charge (SoC) of the battery packs are controlled by local controllers to prevent over-charge and Deep-Discharge. Case studies using a Real-Time Digital Simulator (RTDS) validate that the proposed ADE-based hierarchical control can effectively reduce the distribution power loss and regulate the bus voltages within the tolerances in DC microgrids.
