Pub Date : 2015-10-01DOI: 10.4018/IJEOE.2015100104
M. Elrawemi, L. Blunt, L. Fleming, F. Sweeney, D. Robbins, D. Bird
Flexible Cu (In, Ga) Se2 (CIGS) solar cells are very attractive renewable energy sources because of their high conversion efficiencies, their low cost potential and their many application possibilities. However, they are at present highly susceptible to long term environmental degradation as a result of water vapor ingress through the protective encapsulation layer to the absorber (CIGS) layer. The basic methodology to prevent the water vapor permeation is to combine an oxide layer (e.g. AlOx) coating with suitable polymer substrates. Nevertheless, micro and nano-scale defects can appear at any stage of the coating process thus affecting the module efficiency and lifespan. The main aim of this research paper is to use surface metrology techniques including: White Light Scanning Interferometry (WLSI), Atomic Force Microscopy (AFM) and Environmental Scanning Electron Microscopy (ESEM) to characterise the aluminum oxide (Al2O3) barrier film defects, which appear to be directly responsible for the water vapor permeability. This paper reports on the development of a characterisation method for defect detection based on “Wolf Pruning” method and then correlates this with measured water vapor transmission rates (WVTRs) using standard MOCON® test. The results presented in this paper provided a detailed knowledge of the nature of micro and nano-scale defects on the Al2O3 barrier films which are responsible for water vapor and oxygen ingress. This result can then be used to provide the basis for developing roll-to-roll in process metrology devices for quality control of flexible PV module manufacture.
{"title":"Metrology of Al2O3 Barrier Film for Flexible CIGS Solar Cells","authors":"M. Elrawemi, L. Blunt, L. Fleming, F. Sweeney, D. Robbins, D. Bird","doi":"10.4018/IJEOE.2015100104","DOIUrl":"https://doi.org/10.4018/IJEOE.2015100104","url":null,"abstract":"Flexible Cu (In, Ga) Se2 (CIGS) solar cells are very attractive renewable energy sources because of their high conversion efficiencies, their low cost potential and their many application possibilities. However, they are at present highly susceptible to long term environmental degradation as a result of water vapor ingress through the protective encapsulation layer to the absorber (CIGS) layer. The basic methodology to prevent the water vapor permeation is to combine an oxide layer (e.g. AlOx) coating with suitable polymer substrates. Nevertheless, micro and nano-scale defects can appear at any stage of the coating process thus affecting the module efficiency and lifespan. \u0000The main aim of this research paper is to use surface metrology techniques including: White Light Scanning Interferometry (WLSI), Atomic Force Microscopy (AFM) and Environmental Scanning Electron Microscopy (ESEM) to characterise the aluminum oxide (Al2O3) barrier film defects, which appear to be directly responsible for the water vapor permeability. This paper reports on the development of a characterisation method for defect detection based on “Wolf Pruning” method and then correlates this with measured water vapor transmission rates (WVTRs) using standard MOCON® test. The results presented in this paper provided a detailed knowledge of the nature of micro and nano-scale defects on the Al2O3 barrier films which are responsible for water vapor and oxygen ingress. This result can then be used to provide the basis for developing roll-to-roll in process metrology devices for quality control of flexible PV module manufacture.","PeriodicalId":246250,"journal":{"name":"Int. J. Energy Optim. Eng.","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115275990","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-07-01DOI: 10.4018/IJEOE.2015070102
I. Yahyaoui, M. Chaabene, F. Tadeo
A proposal for energy management in an off-grid photovoltaic pumping and irrigation system is presented and evaluated for a specific case study. The system is assumed to be based on off-the-shelf components (photovoltaic panels, battery banks, DC/AC converters, relays, submergible pumps, etc.), with a microcontroller-based energy management system, deciding when to disconnect the load from the photovoltaic panels or the battery, or the battery from the photovoltaic panels. The aim is to reduce the battery bank us, but always fulfilling the irrigation demand. Using a specific case study (for tomatoes irrigation in Tunisia), the proposal is evaluated, showing that it fulfills the irrigation water demand, using the batteries only when really needed.
{"title":"Energy Management for Photovoltaic Irrigation with a Battery Bank","authors":"I. Yahyaoui, M. Chaabene, F. Tadeo","doi":"10.4018/IJEOE.2015070102","DOIUrl":"https://doi.org/10.4018/IJEOE.2015070102","url":null,"abstract":"A proposal for energy management in an off-grid photovoltaic pumping and irrigation system is presented and evaluated for a specific case study. The system is assumed to be based on off-the-shelf components (photovoltaic panels, battery banks, DC/AC converters, relays, submergible pumps, etc.), with a microcontroller-based energy management system, deciding when to disconnect the load from the photovoltaic panels or the battery, or the battery from the photovoltaic panels. The aim is to reduce the battery bank us, but always fulfilling the irrigation demand. Using a specific case study (for tomatoes irrigation in Tunisia), the proposal is evaluated, showing that it fulfills the irrigation water demand, using the batteries only when really needed.","PeriodicalId":246250,"journal":{"name":"Int. J. Energy Optim. Eng.","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133114754","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-07-01DOI: 10.4018/IJEOE.2015070101
Hejra Msaddek, A. Mansouri, H. Trabelsi
The objective of this work is to find the optimal geometric parameters for the design of permanent magnet synchronous machines (PMSM) with inversed structure (outer rotor) for electric vehicles applications. Firstly, the machine model is presented with a special attention given to the calculation of the mass and engine efficiency. A multi objective optimization based on the genetic algorithm is then implemented. It will determine the parameters values that optimize the chosen criteria while respecting the specifications: to minimizing the total mass and maximizing the machine efficiency. Finally, 2D steady-state finite element analysis is used for to verify the results given by the optimization method.
{"title":"Optimization of In-Wheel Permanent Magnet Synchronous Motor for Electric Car","authors":"Hejra Msaddek, A. Mansouri, H. Trabelsi","doi":"10.4018/IJEOE.2015070101","DOIUrl":"https://doi.org/10.4018/IJEOE.2015070101","url":null,"abstract":"The objective of this work is to find the optimal geometric parameters for the design of permanent magnet synchronous machines (PMSM) with inversed structure (outer rotor) for electric vehicles applications. Firstly, the machine model is presented with a special attention given to the calculation of the mass and engine efficiency. A multi objective optimization based on the genetic algorithm is then implemented. It will determine the parameters values that optimize the chosen criteria while respecting the specifications: to minimizing the total mass and maximizing the machine efficiency. Finally, 2D steady-state finite element analysis is used for to verify the results given by the optimization method.","PeriodicalId":246250,"journal":{"name":"Int. J. Energy Optim. Eng.","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127904597","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-07-01DOI: 10.4018/IJEOE.2015070104
W. Karaa, S. Karaa, A. Ashour
Renewable energy generation (Wind, solar …) is rising rapidly around the world. Energy storage is being today realistic with some kind of variable renewable electricity sources such as the Pumped Hydraulic Storage (PHS). The incorporation of the PHS requires different policies since there are a variety of electric generation technologies that can be exploited commonly with the PHS. The energy management system, the scheduling of the generation units is a crucial problem for which adequate solutions can optimize the energy supply. This paper focuses on the applicability of the PHS technology in the development of renewable energy generation in Tunisia. This paper proposes also a multi agent system that can be implemented to simulate the exploitation of the PHS, commonly with other energy sources: conventional energy, wind energy, photovoltaic energy etc.
{"title":"Renewable Energy Management with a Multi-Agent System","authors":"W. Karaa, S. Karaa, A. Ashour","doi":"10.4018/IJEOE.2015070104","DOIUrl":"https://doi.org/10.4018/IJEOE.2015070104","url":null,"abstract":"Renewable energy generation (Wind, solar …) is rising rapidly around the world. Energy storage is being today realistic with some kind of variable renewable electricity sources such as the Pumped Hydraulic Storage (PHS). The incorporation of the PHS requires different policies since there are a variety of electric generation technologies that can be exploited commonly with the PHS. The energy management system, the scheduling of the generation units is a crucial problem for which adequate solutions can optimize the energy supply. This paper focuses on the applicability of the PHS technology in the development of renewable energy generation in Tunisia. This paper proposes also a multi agent system that can be implemented to simulate the exploitation of the PHS, commonly with other energy sources: conventional energy, wind energy, photovoltaic energy etc.","PeriodicalId":246250,"journal":{"name":"Int. J. Energy Optim. Eng.","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125249675","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-07-01DOI: 10.4018/IJEOE.2015070103
Yosra Welhazi, T. Guesmi, H. H. Abdallah
Applying multi-objective particle swarm optimization (MOPSO) algorithm to multi-objective design of multimachine power system stabilizers (PSSs) is presented in this paper. The proposed approach is based on MOPSO algorithm to search for optimal parameter settings of PSS for a wide range of operating conditions. Moreover, a fuzzy set theory is developed to extract the best compromise solution. The stabilizers are selected using MOPSO to shift the lightly damped and undamped electromechanical modes to a prescribed zone in the s-plane. The problem of tuning the stabilizer parameters is converted to an optimization problem with eigenvalue-based multi-objective function. The performance of the proposed approach is investigated for a three-machine nine-bus system under different operating conditions. The effectiveness of the proposed approach in damping the electromechanical modes and enhancing greatly the dynamic stability is confirmed through eigenvalue analysis, nonlinear simulation results and some performance indices over a wide range of loading conditions.
{"title":"Eigenvalue Assignments in Multimachine Power Systems using Multi-Objective PSO Algorithm","authors":"Yosra Welhazi, T. Guesmi, H. H. Abdallah","doi":"10.4018/IJEOE.2015070103","DOIUrl":"https://doi.org/10.4018/IJEOE.2015070103","url":null,"abstract":"Applying multi-objective particle swarm optimization (MOPSO) algorithm to multi-objective design of multimachine power system stabilizers (PSSs) is presented in this paper. The proposed approach is based on MOPSO algorithm to search for optimal parameter settings of PSS for a wide range of operating conditions. Moreover, a fuzzy set theory is developed to extract the best compromise solution. The stabilizers are selected using MOPSO to shift the lightly damped and undamped electromechanical modes to a prescribed zone in the s-plane. The problem of tuning the stabilizer parameters is converted to an optimization problem with eigenvalue-based multi-objective function. The performance of the proposed approach is investigated for a three-machine nine-bus system under different operating conditions. The effectiveness of the proposed approach in damping the electromechanical modes and enhancing greatly the dynamic stability is confirmed through eigenvalue analysis, nonlinear simulation results and some performance indices over a wide range of loading conditions.","PeriodicalId":246250,"journal":{"name":"Int. J. Energy Optim. Eng.","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127184938","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-04-01DOI: 10.4018/IJEOE.2015040101
S. V. Zharkov
The paper presents methods for assessing economic, resource and environmental efficiency of cogeneration plants (CPs) and energy supply systems as a whole and ways of its improvement, the main of which are the development of cogeneration and renewable energy sources (RES). The problem of allocating fuel and financial costs at the combined production in accordance with the criterion of equal profitability of supplied energy products is solved. The methods allow determining specific indicators of supplied energy products. The technology of introducing RES-based power plants to the energy supply systems by means of using unstabilized RES-based power for direct fuel substitution in thermal cycles of gas-turbine (combined cycle) and steam-turbine plants (the wind is viewed as the most promising type of RES). Connection of wind power plants to an electric grid through thermal power plants allows us to avoid solving the problems of maintaining power quality and operating reserve of the wind power plants capacity in the power system and also to use wind energy at the plants of combined heat and high-quality electric power production, small ones included. The technology can promote smooth transition to hydrogen energy. It is shown that the cogeneration saves more than 20% of fuel, and its combination with wind power station – more than 50%.
{"title":"Assessment and Enhancement of the Energy Supply System Efficiency with Emphasis on the Cogeneration and Renewable as Main Directions for Fuel Saving","authors":"S. V. Zharkov","doi":"10.4018/IJEOE.2015040101","DOIUrl":"https://doi.org/10.4018/IJEOE.2015040101","url":null,"abstract":"The paper presents methods for assessing economic, resource and environmental efficiency of cogeneration plants (CPs) and energy supply systems as a whole and ways of its improvement, the main of which are the development of cogeneration and renewable energy sources (RES). The problem of allocating fuel and financial costs at the combined production in accordance with the criterion of equal profitability of supplied energy products is solved. The methods allow determining specific indicators of supplied energy products. The technology of introducing RES-based power plants to the energy supply systems by means of using unstabilized RES-based power for direct fuel substitution in thermal cycles of gas-turbine (combined cycle) and steam-turbine plants (the wind is viewed as the most promising type of RES). Connection of wind power plants to an electric grid through thermal power plants allows us to avoid solving the problems of maintaining power quality and operating reserve of the wind power plants capacity in the power system and also to use wind energy at the plants of combined heat and high-quality electric power production, small ones included. The technology can promote smooth transition to hydrogen energy. It is shown that the cogeneration saves more than 20% of fuel, and its combination with wind power station – more than 50%.","PeriodicalId":246250,"journal":{"name":"Int. J. Energy Optim. Eng.","volume":"9 4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116757740","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-04-01DOI: 10.4018/IJEOE.2015040102
Shanchari Laik, S. Dey, Puja Das, S. Sultana, S. Paul, P. Roy
Automatic generation control (AGC) is added in power system to ensure constancy in frequency and tie-line power of an interconnected multi-area power system. In this article, proportional integral (PI) controlled based AGC of two-area hydrothermal system is solved by cuckoo optimization algorithm (COA). It is one of the most powerful stochastic real parameter optimization in current use. The design objective is to improve the dynamic performance of the interconnected system following a disturbance. System performance is examined considering 1% step load perturbation in thermal area with generation rate constraints. The results are compared with BBO, GA and DE to show the effectiveness of the proposed method. Computed results shows that the proposed method effectively improve the performance of the objective function with corresponding minimization of the overshoot, undershoot and settling time to reach steady state.
{"title":"Automatic Generation Control of Interconnected Power System using Cuckoo Optimization Algorithm","authors":"Shanchari Laik, S. Dey, Puja Das, S. Sultana, S. Paul, P. Roy","doi":"10.4018/IJEOE.2015040102","DOIUrl":"https://doi.org/10.4018/IJEOE.2015040102","url":null,"abstract":"Automatic generation control (AGC) is added in power system to ensure constancy in frequency and tie-line power of an interconnected multi-area power system. In this article, proportional integral (PI) controlled based AGC of two-area hydrothermal system is solved by cuckoo optimization algorithm (COA). It is one of the most powerful stochastic real parameter optimization in current use. The design objective is to improve the dynamic performance of the interconnected system following a disturbance. System performance is examined considering 1% step load perturbation in thermal area with generation rate constraints. The results are compared with BBO, GA and DE to show the effectiveness of the proposed method. Computed results shows that the proposed method effectively improve the performance of the objective function with corresponding minimization of the overshoot, undershoot and settling time to reach steady state.","PeriodicalId":246250,"journal":{"name":"Int. J. Energy Optim. Eng.","volume":"161 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123502843","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-04-01DOI: 10.4018/IJEOE.2015040103
Rahmat Khezri, H. Bevrani
This paper presents performance of intelligent fuzzy-based coordinated control for Automatic Voltage Regulator AVR and Power System Stabilizer PSS, to prevent losing synchronism after major sudden faults and to achieve appropriate post-fault voltage level in multi-machine power systems. The AVR and PSS gains can adaptively change to guarantee the power system stability after faults. For change in AVR and PSS gains, at least one significant generator in each area of a multi-area power system is equipped with fuzzy logic unit. The fuzzy logic unit accepts normalized deviations of terminal voltage and phase difference of synchronous generators as inputs and generates the desirable gains for AVR and PSS. The construction of appropriate fuzzy membership functions and rules for best tuning of gains is described. The proposed fuzzy control methodology is applied to 11-bus 4-generator power system test case. Simulation results illustrate the effectiveness and robustness of the proposed fuzzy-based coordinated control strategy.
{"title":"Stability Enhancement in Multi-Machine Power Systems by Fuzzy-based Coordinated AVR-PSS","authors":"Rahmat Khezri, H. Bevrani","doi":"10.4018/IJEOE.2015040103","DOIUrl":"https://doi.org/10.4018/IJEOE.2015040103","url":null,"abstract":"This paper presents performance of intelligent fuzzy-based coordinated control for Automatic Voltage Regulator AVR and Power System Stabilizer PSS, to prevent losing synchronism after major sudden faults and to achieve appropriate post-fault voltage level in multi-machine power systems. The AVR and PSS gains can adaptively change to guarantee the power system stability after faults. For change in AVR and PSS gains, at least one significant generator in each area of a multi-area power system is equipped with fuzzy logic unit. The fuzzy logic unit accepts normalized deviations of terminal voltage and phase difference of synchronous generators as inputs and generates the desirable gains for AVR and PSS. The construction of appropriate fuzzy membership functions and rules for best tuning of gains is described. The proposed fuzzy control methodology is applied to 11-bus 4-generator power system test case. Simulation results illustrate the effectiveness and robustness of the proposed fuzzy-based coordinated control strategy.","PeriodicalId":246250,"journal":{"name":"Int. J. Energy Optim. Eng.","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128010131","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-04-01DOI: 10.4018/IJEOE.2015040104
S. Paul, P. Roy
PSSs are added to excitation systems to enhance the damping during low frequency oscillations. The non-linear model of a machine is linearized at different operating points. Chemical Reaction optimization (CRO), a new population based search algorithm is been proposed in this paper to damp the power system low-frequency oscillations and enhance power system stability. Computation results demonstrate that the proposed algorithm is effective in damping low frequency oscillations as well as improving system dynamic stability. The performance of the proposed algorithm is evaluated for different loading conditions. In addition, the proposed algorithm is more effective and provides superior performance when compared other population based optimization algorithms like differential evolution (DE) and particle swarm optimization (PSO).
{"title":"Optimal Design of Single Machine Power System Stabilizer using Chemical Reaction Optimization Technique","authors":"S. Paul, P. Roy","doi":"10.4018/IJEOE.2015040104","DOIUrl":"https://doi.org/10.4018/IJEOE.2015040104","url":null,"abstract":"PSSs are added to excitation systems to enhance the damping during low frequency oscillations. The non-linear model of a machine is linearized at different operating points. Chemical Reaction optimization (CRO), a new population based search algorithm is been proposed in this paper to damp the power system low-frequency oscillations and enhance power system stability. Computation results demonstrate that the proposed algorithm is effective in damping low frequency oscillations as well as improving system dynamic stability. The performance of the proposed algorithm is evaluated for different loading conditions. In addition, the proposed algorithm is more effective and provides superior performance when compared other population based optimization algorithms like differential evolution (DE) and particle swarm optimization (PSO).","PeriodicalId":246250,"journal":{"name":"Int. J. Energy Optim. Eng.","volume":"64 6","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131579672","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}