... This paper addresses dynamic modeling and control of a grid-connected windPVbattery hybrid ... more ... This paper addresses dynamic modeling and control of a grid-connected windPVbattery hybrid system with versatile power transfer. The hybrid system, unlike conventional sys-tems, considers the stability and dispatch-ability of its power injection into the grid. ...
A methodology for optimal sizing of stand-alone PV/WG systems is presented. The purpose of the pr... more A methodology for optimal sizing of stand-alone PV/WG systems is presented. The purpose of the proposed methodology is to suggest, among a list of commercially available system devices, the optimal number and type of units ensuring that the 20-year round total system cost is minimized subject to the constraint that the load energy requirements are completely covered, resulting in zero load rejection. The 20-year round total system cost is equal to the sum of the respective components capital and maintenance costs. The cost (objective) function minimization is implemented using genetic algorithms, which, compared to conventional optimization methods such as dynamic programming and gradient techniques, have the ability to attain the global optimum with relative computational simplicity. The proposed method has been applied for the design of a power generation system which supplies a residential household. The simulation results verify that hybrid PV/WG systems feature lower system cost compared to the cases where either exclusively WG or exclusively PV sources are used.
A variable structure controller to regulate the output power of a standalone hybrid generation sy... more A variable structure controller to regulate the output power of a standalone hybrid generation system is presented. The system comprises photovoltaic and wind generation, a storage battery bank and a variable monophasic load. The control law admits two modes of operation. The first takes place when the insolation regime is sufficient to satisfy the power demand. The second mode of operation takes place under insufficient insolation regimes. The latter leads the system operation at the maximum power operation point (MPOP) to save as much stored energy as possible. A new method based on the IncCond algorithm is developed. Sliding mode control techniques are used to design the control law. These techniques provide a simple control law design framework and contribute with their well known robustness properties. Finally, guidelines based on chattering considerations are given for the design of the practical system.
Stand-alone power system PEM Electrolyzer PEM fuel cell Lead-acid accumulator Hydrogen production... more Stand-alone power system PEM Electrolyzer PEM fuel cell Lead-acid accumulator Hydrogen production Power management strategy a b s t r a c t A stand-alone power system based on a photovoltaic array and wind generators that stores the excessive energy from renewable energy sources (RES) in the form of hydrogen via water electrolysis for future use in a polymer electrolyte membrane (PEM) fuel cell is currently in operation at Neo Olvio of Xanthi, Greece. Efficient power management strategies (PMSs) for the system have been developed. The PMSs have been assessed on their capacity to meet the power load requirements through effective utilization of the electrolyzer and fuel cell under variable energy generation from RES (solar and wind). The evaluation of the PMS has been performed through simulated experiments with anticipated conditions over a typical four-month time period for the region of installation. The key decision factors for the PMSs are the level of the power provided by the RES and the state of charge (SOC) of the accumulator. Therefore, the operating policies for the hydrogen production via water electrolysis and the hydrogen consumption at the fuel cell depend on the excess or shortage of power from the RES and the level of SOC. A parametric sensitivity analysis investigates the influence of major operating variables for the PMSs such as the minimum SOC level and the operating characteristics of the electrolyzer and the fuel cell in the performance of the integrated system. ª A v a i l a b l e a t w w w . s c i e n c e d i r e c t . c o m j o u r n a l h o m e p a g e : w w w . e l s e v i e r . c o m / l o c a t e / h e
An economic evaluation of a hybrid wind/photovoltaic/fuel cell (FC) generation system for a typic... more An economic evaluation of a hybrid wind/photovoltaic/fuel cell (FC) generation system for a typical home in the Pacific Northwest is performed. In this configuration the combination of a FC stack, an electrolyser, and hydrogen storage tanks is used as the energy storage system. ...
In this paper a wind resource map of Newfoundland is presented. A set of mesoscale wind maps, gen... more In this paper a wind resource map of Newfoundland is presented. A set of mesoscale wind maps, generated with the aid of NASA and NCEP/NCAR databases was studied for establishing a general pattern of wind speed variation throughout Newfoundland. Ground data from some key locations around Newfoundland is extrapolated for height and surface condition adjustments. By combining the modified ground data with one suitable global data based mesoscale map, a wind resource map indicating various classes of wind potential has been developed. It has been found that wind speed is generally higher in the coastal regions. Eastern Newfoundland, Northern Peninsula and Burin Peninsula have higher wind potential than the Avalon Peninsula and the western coast. Wind speed gradually increases from central Newfoundland towards the coasts. Several suggestions for further investigation and development of a complete wind map are also given. #
Supervisory control Ultra-capacitor a b s t r a c t Depending on growing concerns on energy crise... more Supervisory control Ultra-capacitor a b s t r a c t Depending on growing concerns on energy crises and environmental issues, fuel cell (FC) powered electrical vehicles are favored for possible substitute to conventional internal combustion engine (ICE) based vehicular systems. However, the typical power profile of an automobile motor consisting of transients is not suitable for the use of a sole FC system for vehicle propulsion. This shortcoming could be partly overcome by hybridization. Two potential benefits of combining an FC system with an energy storage unit, ultra-capacitor (UC) has been presented in this study. Firstly, the durability of the FC system could be improved because the additional energy source can fulfill the transient power demand fluctuations. Secondly, the ability of the energy storage source to recover braking energy enhances the fuel economy greatly. An important aspect in designing a hybrid power structure is to find a suitable control strategy that can manage the active power sharing and take advantage of the inherent scalability and robustness benefits of the hybrid system. An integrated procedure for mathematical modeling and power control strategy design for an FC/UC hybrid vehicle is presented in this paper. A fuzzy logic supervisory controller based power management strategy that secures the power balance in hybrid structure, enhances the FC performance and minimizes the power losses is proposed. The main contribution of this paper apart from the previous studies of the authors is the modeling of the complete FC power system with air supply compressor and the integration of the control of the FC system internal dynamics (especially the oxygen excess ratio) into the overall supervisory control structure to maximize the efficiency and durability. To demonstrate the effectiveness of the proposed power management scheme, simulation studies were performed using MATLAB Ò , Simulink Ò and SimPowerSystems Ò environments by integrating the detailed mathematical and electrical models of the hybrid vehicular system.
All the copyright of the present book belongs to the editors. All rights reserved. No part of thi... more All the copyright of the present book belongs to the editors. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of the editors.
... of the windRV generators, storage batteries, and the backup generator; the balance of system ... more ... of the windRV generators, storage batteries, and the backup generator; the balance of system ... B. S. Borowy and ZM Salameh, "Optimum Photovoltaic Array Size for a Hybrid WindRV ... Ito, Y. Yuasa, "Multiobjective Optimal Unit Sizing of Hybrid Power Generation Systems Utilizing ...
... This paper addresses dynamic modeling and control of a grid-connected windPVbattery hybrid ... more ... This paper addresses dynamic modeling and control of a grid-connected windPVbattery hybrid system with versatile power transfer. The hybrid system, unlike conventional sys-tems, considers the stability and dispatch-ability of its power injection into the grid. ...
A methodology for optimal sizing of stand-alone PV/WG systems is presented. The purpose of the pr... more A methodology for optimal sizing of stand-alone PV/WG systems is presented. The purpose of the proposed methodology is to suggest, among a list of commercially available system devices, the optimal number and type of units ensuring that the 20-year round total system cost is minimized subject to the constraint that the load energy requirements are completely covered, resulting in zero load rejection. The 20-year round total system cost is equal to the sum of the respective components capital and maintenance costs. The cost (objective) function minimization is implemented using genetic algorithms, which, compared to conventional optimization methods such as dynamic programming and gradient techniques, have the ability to attain the global optimum with relative computational simplicity. The proposed method has been applied for the design of a power generation system which supplies a residential household. The simulation results verify that hybrid PV/WG systems feature lower system cost compared to the cases where either exclusively WG or exclusively PV sources are used.
A variable structure controller to regulate the output power of a standalone hybrid generation sy... more A variable structure controller to regulate the output power of a standalone hybrid generation system is presented. The system comprises photovoltaic and wind generation, a storage battery bank and a variable monophasic load. The control law admits two modes of operation. The first takes place when the insolation regime is sufficient to satisfy the power demand. The second mode of operation takes place under insufficient insolation regimes. The latter leads the system operation at the maximum power operation point (MPOP) to save as much stored energy as possible. A new method based on the IncCond algorithm is developed. Sliding mode control techniques are used to design the control law. These techniques provide a simple control law design framework and contribute with their well known robustness properties. Finally, guidelines based on chattering considerations are given for the design of the practical system.
Stand-alone power system PEM Electrolyzer PEM fuel cell Lead-acid accumulator Hydrogen production... more Stand-alone power system PEM Electrolyzer PEM fuel cell Lead-acid accumulator Hydrogen production Power management strategy a b s t r a c t A stand-alone power system based on a photovoltaic array and wind generators that stores the excessive energy from renewable energy sources (RES) in the form of hydrogen via water electrolysis for future use in a polymer electrolyte membrane (PEM) fuel cell is currently in operation at Neo Olvio of Xanthi, Greece. Efficient power management strategies (PMSs) for the system have been developed. The PMSs have been assessed on their capacity to meet the power load requirements through effective utilization of the electrolyzer and fuel cell under variable energy generation from RES (solar and wind). The evaluation of the PMS has been performed through simulated experiments with anticipated conditions over a typical four-month time period for the region of installation. The key decision factors for the PMSs are the level of the power provided by the RES and the state of charge (SOC) of the accumulator. Therefore, the operating policies for the hydrogen production via water electrolysis and the hydrogen consumption at the fuel cell depend on the excess or shortage of power from the RES and the level of SOC. A parametric sensitivity analysis investigates the influence of major operating variables for the PMSs such as the minimum SOC level and the operating characteristics of the electrolyzer and the fuel cell in the performance of the integrated system. ª A v a i l a b l e a t w w w . s c i e n c e d i r e c t . c o m j o u r n a l h o m e p a g e : w w w . e l s e v i e r . c o m / l o c a t e / h e
An economic evaluation of a hybrid wind/photovoltaic/fuel cell (FC) generation system for a typic... more An economic evaluation of a hybrid wind/photovoltaic/fuel cell (FC) generation system for a typical home in the Pacific Northwest is performed. In this configuration the combination of a FC stack, an electrolyser, and hydrogen storage tanks is used as the energy storage system. ...
In this paper a wind resource map of Newfoundland is presented. A set of mesoscale wind maps, gen... more In this paper a wind resource map of Newfoundland is presented. A set of mesoscale wind maps, generated with the aid of NASA and NCEP/NCAR databases was studied for establishing a general pattern of wind speed variation throughout Newfoundland. Ground data from some key locations around Newfoundland is extrapolated for height and surface condition adjustments. By combining the modified ground data with one suitable global data based mesoscale map, a wind resource map indicating various classes of wind potential has been developed. It has been found that wind speed is generally higher in the coastal regions. Eastern Newfoundland, Northern Peninsula and Burin Peninsula have higher wind potential than the Avalon Peninsula and the western coast. Wind speed gradually increases from central Newfoundland towards the coasts. Several suggestions for further investigation and development of a complete wind map are also given. #
Supervisory control Ultra-capacitor a b s t r a c t Depending on growing concerns on energy crise... more Supervisory control Ultra-capacitor a b s t r a c t Depending on growing concerns on energy crises and environmental issues, fuel cell (FC) powered electrical vehicles are favored for possible substitute to conventional internal combustion engine (ICE) based vehicular systems. However, the typical power profile of an automobile motor consisting of transients is not suitable for the use of a sole FC system for vehicle propulsion. This shortcoming could be partly overcome by hybridization. Two potential benefits of combining an FC system with an energy storage unit, ultra-capacitor (UC) has been presented in this study. Firstly, the durability of the FC system could be improved because the additional energy source can fulfill the transient power demand fluctuations. Secondly, the ability of the energy storage source to recover braking energy enhances the fuel economy greatly. An important aspect in designing a hybrid power structure is to find a suitable control strategy that can manage the active power sharing and take advantage of the inherent scalability and robustness benefits of the hybrid system. An integrated procedure for mathematical modeling and power control strategy design for an FC/UC hybrid vehicle is presented in this paper. A fuzzy logic supervisory controller based power management strategy that secures the power balance in hybrid structure, enhances the FC performance and minimizes the power losses is proposed. The main contribution of this paper apart from the previous studies of the authors is the modeling of the complete FC power system with air supply compressor and the integration of the control of the FC system internal dynamics (especially the oxygen excess ratio) into the overall supervisory control structure to maximize the efficiency and durability. To demonstrate the effectiveness of the proposed power management scheme, simulation studies were performed using MATLAB Ò , Simulink Ò and SimPowerSystems Ò environments by integrating the detailed mathematical and electrical models of the hybrid vehicular system.
All the copyright of the present book belongs to the editors. All rights reserved. No part of thi... more All the copyright of the present book belongs to the editors. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of the editors.
... of the windRV generators, storage batteries, and the backup generator; the balance of system ... more ... of the windRV generators, storage batteries, and the backup generator; the balance of system ... B. S. Borowy and ZM Salameh, "Optimum Photovoltaic Array Size for a Hybrid WindRV ... Ito, Y. Yuasa, "Multiobjective Optimal Unit Sizing of Hybrid Power Generation Systems Utilizing ...
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