In this paper, a stand-alone hybrid microgrid consisting of wind turbines, photovoltaic (PV) arrays and storage battery banks is developed for use in Qinghai Province, China. With the help of Software Homer and Matlab...In this paper, a stand-alone hybrid microgrid consisting of wind turbines, photovoltaic (PV) arrays and storage battery banks is developed for use in Qinghai Province, China. With the help of Software Homer and Matlab, different variables such as annual average wind speed, annual average load demand, and annual capacity shortage are considered. The net present value is then used during an entire project lifetime for the optimization solution.展开更多
Renewable energy sources(RESs)are considered to be reliable and green electric power generation sources.Photovoltaics(PVs)and wind turbines(WTs)are used to provide electricity in remote areas.Optimal sizing of hybrid ...Renewable energy sources(RESs)are considered to be reliable and green electric power generation sources.Photovoltaics(PVs)and wind turbines(WTs)are used to provide electricity in remote areas.Optimal sizing of hybrid RESs is a vital challenge in a stand-alone environment.The meta-heuristic algorithms proposed in the past are dependent on algorithm-specific parameters for achieving an optimal solution.This paper proposes a hybrid algorithm of Jaya and a teaching–learning-based optimization(TLBO)named the JLBO algorithm for the optimal unit sizing of a PV–WT–battery hybrid system to satisfy the consumer’s load at minimal total annual cost(TAC).The reliability of the system is considered by a maximum allowable loss of power supply probability(LPSPmax)concept.The results obtained from the JLBO algorithm are compared with the original Jaya,TLBO,and genetic algorithms.The JLBO results show superior performance in terms of TAC,and the PV–WT–battery hybrid system is found to be the most economical scenario.This system provides a cost-effective solution for all proposed LPSPmax values as compared with PV–battery and WT–battery systems.展开更多
This paper presents a design for a stand-alone photovoltaic (PV) system to provide the required electricity for a single residential household in rural area in Jordan. The complete design steps for the suggested house...This paper presents a design for a stand-alone photovoltaic (PV) system to provide the required electricity for a single residential household in rural area in Jordan. The complete design steps for the suggested household loads are carried out. Site radiation data and the electrical load data of a typical household in the considered site are taken into account during the design steps. The reliability of the system is quantified by the loss of load probability. A computer program is developed to simulate the PV system behavior and to numerically find an optimal combination of PV array and battery bank for the design of stand-alone photovoltaic systems in terms of reliability and costs. The program calculates life cycle cost and annualized unit electrical cost. Simulations results showed that a value of loss of load probability LLP can be met by several combinations of PV array and battery storage. The method developed here uniquely determines the optimum configuration that meets the load demand with the minimum cost. The difference between the costs of these combinations is very large. The optimal unit electrical cost of 1 kWh for LLP = 0.049 is $0.293;while for LLP 0.0027 it is $0.402. The results of the study encouraged the use of the PV systems to electrify the remote sites in Jordan.展开更多
This paper describes the characteristics and optimal methods for the planning of stand-alone microgrid system, in order to improve the power supply reliability, increase the coefficient of utilization of renewable ene...This paper describes the characteristics and optimal methods for the planning of stand-alone microgrid system, in order to improve the power supply reliability, increase the coefficient of utilization of renewable energy and reduce the cost of investment and operation. Next, the problems in the optimal planning for a stand-alone microgrid system are summarized, including the unique operational control targets, the flexible combination approaches and the operation strategies of distributed generation energy supply system, and the special requirements of the reliability of power supply quality factor from the different users. And then, centering on the operational control and the advanced energy management strategy, the optimal mathematical models and the solving methods, the reliability assessment approaches and the improvement measures of a stand-alone microgrid system, an overview of the general situation of the recent research at home and abroad and the limitations of the study are summarized. Finally, several problems, existing in the optimal planning of stand-alone microgrid system, to be urgently solved, are put forward.展开更多
Application of a DFIG (doubly-fed induction generator), which is one of adjustable speed generators, to a gas engine cogeneration system has been investigated. To operate during a blackout as an emergency power supp...Application of a DFIG (doubly-fed induction generator), which is one of adjustable speed generators, to a gas engine cogeneration system has been investigated. To operate during a blackout as an emergency power supply is one of important roles for the gas engine eogeneration system. In the case of conventional constant speed of synchronous generator, the amount of the allowed step load is limited to around 30% of the rated power. On the other hand, DFIG is expected to increase the amount of step load during the stand-alone operation. In this paper, it has been demonstrated that an increase in the gas engine speed resulted in an increase in the maximum amount of step load using experimental equipment with a real gas engine. It has been concluded that the proposed system can improve the performance of an emergency power supply at step-loading.展开更多
This paper deals with control method related to a wind system operating in stand-alone applications. The stand-alone wind system is composed of three energy transfer subsystems: wind generator subsystem (wind turbin...This paper deals with control method related to a wind system operating in stand-alone applications. The stand-alone wind system is composed of three energy transfer subsystems: wind generator subsystem (wind turbine and electrical generator), energy storage subsystem, respectively, specific local network subsystem (controlled loads). This wind power system performs in the same time the maximization of wind energy conversion and the power balance between produced and required power. Three structures of the energy storage subsystem, based on buffer battery operation and/or capacitor voltage control, are discussed. The simulation results show that the proposed stand-alone wind power system ensures a good management of the local energy request. The design of the structures is analyzed in Matlab/Simulink environment, using PowerSim toolbox.展开更多
In the process of spectrum perception,in order to realize accurate perception of the channel state,the method of multi-node cooperative perception can usually be used.However,the first problem to be considered is how ...In the process of spectrum perception,in order to realize accurate perception of the channel state,the method of multi-node cooperative perception can usually be used.However,the first problem to be considered is how to complete information fusion and obtain more accurate and reliable judgment results based on multi-node perception results.The ideas put forward in this paper are as follows:firstly,the perceived results of each node are obtained on the premise of limiting detection probability and false alarm probability.Then,on the one hand,the weighted fusion criterion of decision-making weight optimization of each node is realized based on a genetic algorithm,and the useless nodes also can be screened out to reduce energy loss;on the other hand,through the linear fitting ability of RBF neural network,the self-inspection of the perceptive nodes can be realized to ensure the normal operation of the perceptive work of each node.What's more,the real-time training data can be obtained by spectral segmentation technology to ensure the real-time accuracy of the optimization results.Finally,the simulation results show that this method can effectively improve the accuracy and stability of channel perception results,optimize the structure of the cooperative network and reduce energy consumption.展开更多
Synchronized acoustic-articulatory data is the basis of various applications,such as exploring the fundamental mechanisms of speech production,acoustic to articulatory inversion(AAI),and articulatory to acoustic mappi...Synchronized acoustic-articulatory data is the basis of various applications,such as exploring the fundamental mechanisms of speech production,acoustic to articulatory inversion(AAI),and articulatory to acoustic mapping(AAM).Numerous studies have been conducted based on the synchronized ElectroMagnetic Articulograhy(EMA)data and acoustic data.Hence,it is necessary to make clear whether the EMA-synchronized speech and stand-alone speech are different,and if so,how it affects the performance of the applications that are based on synchronized acoustic-articulatory data.In this study,we compare the differences between EMA-synchronized speech and stand-alone speech from the aspect of speech recognition based on the data of a male speaker.It is found that:i)the general error rate of EMA-synchronized speech is much higher than that of stand-alone speech;ii)apical vowels and apical/blade consonants are more significantly affected by the presence of EMA coils;iii)parts of vowel and consonant tokens are confused with the sounds who use the same articulator or the articulators nearby,such as confusion among apical vowels and confusion among apical and blade consonants;iv)the confusion of labial tokens demonstrates a diverse pattern.展开更多
This paper proposes a new method for the planning of stand-alone microgrids.By means of clustering techniques,possible operating scenarios are obtained considering the daily patterns of wind and load profiles.Then,an ...This paper proposes a new method for the planning of stand-alone microgrids.By means of clustering techniques,possible operating scenarios are obtained considering the daily patterns of wind and load profiles.Then,an approximate analytical model for reliability evaluation of battery energy storage system is developed in terms of the diverse scenarios,along with multistate models for wind energy system and diesel generating system.An optimal planning model is further illustrated based on the scenarios and the reliability models,with the objective of minimizing the present values of the costs occurring within the project lifetime,and with the constraints of system operation and reliability.Finally,a typical stand-alone microgrid is studied to verify the efficiency of the proposed method.展开更多
1 Introduction Early attempts to create a sound absorber which would function without the involvement of any fibrous or porous damping material go far back to K. A. Veliszhanina, S. N. Rschevkin and others as was out...1 Introduction Early attempts to create a sound absorber which would function without the involvement of any fibrous or porous damping material go far back to K. A. Veliszhanina, S. N. Rschevkin and others as was outlined in Ref. [1]. 30 years ago, D. Y. MAA[2] was first in proposing a practicable design concept and calculation model for Micro-Perforated Absorber (MPA) prototypes which still forms the basis for various applications. During the past 12 years the Fraunhofer IBP developed a whole family of MPA products in close cooperation with 8 or more industrial partners operating in a variety of widely differing market segments. Meanwhile a large number of MPA modules and surface elements have evolved from MAA's creative pioneer work. More and more ambitious acousticians have, more recently, caught on this attractive idea of employing absorbers made of non-fibrous, non-abrasive materials with non-polluting, almost closed and optically attractive surfaces. MPA structures have played an important part in a long-standing and on-going effort at IBP to establish novel Alternative Fibreless Absorber (ALFA) tools for a better noise control and acoustic comfort.展开更多
This paper presents a detailed preliminary assessment of load consumption and solar power potential at the Eco-Tourism Centre of Liogu Ku Silou-Silou(EPLISSI),Kota Belud,Sabah.This initial investigation assessed the f...This paper presents a detailed preliminary assessment of load consumption and solar power potential at the Eco-Tourism Centre of Liogu Ku Silou-Silou(EPLISSI),Kota Belud,Sabah.This initial investigation assessed the feasibility of an off-grid solar PV system at EPLISSI with a suitable solar panel system for project installation and commissioning purposes.Due to the absence of an electrical grid and power supply,no pre-existing electrical appliances could be found in EPLISSI.Hence,an excel-based software,the ESCoBox,was used to produce the load profiles.The input data for this software came from a list of required electrical appliances(LED lights,fans,and phone chargers)and the historical frequency of visitors to EPLISSI.Meanwhile,to assess the solar power potential at EPLISSI,an online simulator known as Global Solar Atlas version 2.3 or GSA 2.3 was used.As an input for the GSA 2.3,the initial solar panel system capacity was set for 0.5 kWp,and then an increment of 0.1 kWp was entered until specific criteria were met.The selection of the suitable size is made when the system can satisfy the daily total average load demand and a specific load fulfillment demand.As a result,it was found that the site requires a total average demand and a total peak demand of 4.60 and 11.87 kWh/day,respectively.From the GSA 2.3 generated report,an off-grid solar PV system with the capacity of 2.50 kWp solar PV can satisfy the daily total average load demand of this area,where the average PV energy output is within the range of between 7.74–9.80 kWh/day or an average of 8.72 kWh/day.In conclusion,this preliminary assessment indicates that installing an off-grid solar PV system in this area is possible.展开更多
This paper proposes a sliding mode controller based on robust model reference adaptive proportional-integral(RMRA-PI)control for a stand-alone voltage source inverter(SA-VSI).The proposed controller has two control lo...This paper proposes a sliding mode controller based on robust model reference adaptive proportional-integral(RMRA-PI)control for a stand-alone voltage source inverter(SA-VSI).The proposed controller has two control loops where the coefficients of PI controller are regulated by the adaptive sliding law.This method is used to regulate the output voltage of the inverter under different load conditions and uncertainty,and adapts the output to the reference model to reduce the total harmonic distortion(THD).In this paper,the stability of the proposed controller is proven by using Lyapunov's theory and Barbalet’s lemma.The proposed controller performs well in voltage regulation such as low THD under sudden load change and uncertainty.Also,the results of the proposed controller are compared with PI controller to show the effectiveness of the presented control system.展开更多
文摘In this paper, a stand-alone hybrid microgrid consisting of wind turbines, photovoltaic (PV) arrays and storage battery banks is developed for use in Qinghai Province, China. With the help of Software Homer and Matlab, different variables such as annual average wind speed, annual average load demand, and annual capacity shortage are considered. The net present value is then used during an entire project lifetime for the optimization solution.
文摘Renewable energy sources(RESs)are considered to be reliable and green electric power generation sources.Photovoltaics(PVs)and wind turbines(WTs)are used to provide electricity in remote areas.Optimal sizing of hybrid RESs is a vital challenge in a stand-alone environment.The meta-heuristic algorithms proposed in the past are dependent on algorithm-specific parameters for achieving an optimal solution.This paper proposes a hybrid algorithm of Jaya and a teaching–learning-based optimization(TLBO)named the JLBO algorithm for the optimal unit sizing of a PV–WT–battery hybrid system to satisfy the consumer’s load at minimal total annual cost(TAC).The reliability of the system is considered by a maximum allowable loss of power supply probability(LPSPmax)concept.The results obtained from the JLBO algorithm are compared with the original Jaya,TLBO,and genetic algorithms.The JLBO results show superior performance in terms of TAC,and the PV–WT–battery hybrid system is found to be the most economical scenario.This system provides a cost-effective solution for all proposed LPSPmax values as compared with PV–battery and WT–battery systems.
文摘This paper presents a design for a stand-alone photovoltaic (PV) system to provide the required electricity for a single residential household in rural area in Jordan. The complete design steps for the suggested household loads are carried out. Site radiation data and the electrical load data of a typical household in the considered site are taken into account during the design steps. The reliability of the system is quantified by the loss of load probability. A computer program is developed to simulate the PV system behavior and to numerically find an optimal combination of PV array and battery bank for the design of stand-alone photovoltaic systems in terms of reliability and costs. The program calculates life cycle cost and annualized unit electrical cost. Simulations results showed that a value of loss of load probability LLP can be met by several combinations of PV array and battery storage. The method developed here uniquely determines the optimum configuration that meets the load demand with the minimum cost. The difference between the costs of these combinations is very large. The optimal unit electrical cost of 1 kWh for LLP = 0.049 is $0.293;while for LLP 0.0027 it is $0.402. The results of the study encouraged the use of the PV systems to electrify the remote sites in Jordan.
文摘This paper describes the characteristics and optimal methods for the planning of stand-alone microgrid system, in order to improve the power supply reliability, increase the coefficient of utilization of renewable energy and reduce the cost of investment and operation. Next, the problems in the optimal planning for a stand-alone microgrid system are summarized, including the unique operational control targets, the flexible combination approaches and the operation strategies of distributed generation energy supply system, and the special requirements of the reliability of power supply quality factor from the different users. And then, centering on the operational control and the advanced energy management strategy, the optimal mathematical models and the solving methods, the reliability assessment approaches and the improvement measures of a stand-alone microgrid system, an overview of the general situation of the recent research at home and abroad and the limitations of the study are summarized. Finally, several problems, existing in the optimal planning of stand-alone microgrid system, to be urgently solved, are put forward.
文摘Application of a DFIG (doubly-fed induction generator), which is one of adjustable speed generators, to a gas engine cogeneration system has been investigated. To operate during a blackout as an emergency power supply is one of important roles for the gas engine eogeneration system. In the case of conventional constant speed of synchronous generator, the amount of the allowed step load is limited to around 30% of the rated power. On the other hand, DFIG is expected to increase the amount of step load during the stand-alone operation. In this paper, it has been demonstrated that an increase in the gas engine speed resulted in an increase in the maximum amount of step load using experimental equipment with a real gas engine. It has been concluded that the proposed system can improve the performance of an emergency power supply at step-loading.
文摘This paper deals with control method related to a wind system operating in stand-alone applications. The stand-alone wind system is composed of three energy transfer subsystems: wind generator subsystem (wind turbine and electrical generator), energy storage subsystem, respectively, specific local network subsystem (controlled loads). This wind power system performs in the same time the maximization of wind energy conversion and the power balance between produced and required power. Three structures of the energy storage subsystem, based on buffer battery operation and/or capacitor voltage control, are discussed. The simulation results show that the proposed stand-alone wind power system ensures a good management of the local energy request. The design of the structures is analyzed in Matlab/Simulink environment, using PowerSim toolbox.
文摘In the process of spectrum perception,in order to realize accurate perception of the channel state,the method of multi-node cooperative perception can usually be used.However,the first problem to be considered is how to complete information fusion and obtain more accurate and reliable judgment results based on multi-node perception results.The ideas put forward in this paper are as follows:firstly,the perceived results of each node are obtained on the premise of limiting detection probability and false alarm probability.Then,on the one hand,the weighted fusion criterion of decision-making weight optimization of each node is realized based on a genetic algorithm,and the useless nodes also can be screened out to reduce energy loss;on the other hand,through the linear fitting ability of RBF neural network,the self-inspection of the perceptive nodes can be realized to ensure the normal operation of the perceptive work of each node.What's more,the real-time training data can be obtained by spectral segmentation technology to ensure the real-time accuracy of the optimization results.Finally,the simulation results show that this method can effectively improve the accuracy and stability of channel perception results,optimize the structure of the cooperative network and reduce energy consumption.
基金supported by the National Natural Science Foundation of China(No.61977049)Advanced Innovation Center for Language Resource and Intelligence(KYR17005)
文摘Synchronized acoustic-articulatory data is the basis of various applications,such as exploring the fundamental mechanisms of speech production,acoustic to articulatory inversion(AAI),and articulatory to acoustic mapping(AAM).Numerous studies have been conducted based on the synchronized ElectroMagnetic Articulograhy(EMA)data and acoustic data.Hence,it is necessary to make clear whether the EMA-synchronized speech and stand-alone speech are different,and if so,how it affects the performance of the applications that are based on synchronized acoustic-articulatory data.In this study,we compare the differences between EMA-synchronized speech and stand-alone speech from the aspect of speech recognition based on the data of a male speaker.It is found that:i)the general error rate of EMA-synchronized speech is much higher than that of stand-alone speech;ii)apical vowels and apical/blade consonants are more significantly affected by the presence of EMA coils;iii)parts of vowel and consonant tokens are confused with the sounds who use the same articulator or the articulators nearby,such as confusion among apical vowels and confusion among apical and blade consonants;iv)the confusion of labial tokens demonstrates a diverse pattern.
基金This work was supported by the National High Technology Research and Development Program of China(863 Program)(No.2011AA05A107)the National Natural Science Foundation of China(No.51207099,No.51261130473)the Specialized Research Fund for the Doctoral Program of Higher Education(No.20120032130008).
文摘This paper proposes a new method for the planning of stand-alone microgrids.By means of clustering techniques,possible operating scenarios are obtained considering the daily patterns of wind and load profiles.Then,an approximate analytical model for reliability evaluation of battery energy storage system is developed in terms of the diverse scenarios,along with multistate models for wind energy system and diesel generating system.An optimal planning model is further illustrated based on the scenarios and the reliability models,with the objective of minimizing the present values of the costs occurring within the project lifetime,and with the constraints of system operation and reliability.Finally,a typical stand-alone microgrid is studied to verify the efficiency of the proposed method.
文摘1 Introduction Early attempts to create a sound absorber which would function without the involvement of any fibrous or porous damping material go far back to K. A. Veliszhanina, S. N. Rschevkin and others as was outlined in Ref. [1]. 30 years ago, D. Y. MAA[2] was first in proposing a practicable design concept and calculation model for Micro-Perforated Absorber (MPA) prototypes which still forms the basis for various applications. During the past 12 years the Fraunhofer IBP developed a whole family of MPA products in close cooperation with 8 or more industrial partners operating in a variety of widely differing market segments. Meanwhile a large number of MPA modules and surface elements have evolved from MAA's creative pioneer work. More and more ambitious acousticians have, more recently, caught on this attractive idea of employing absorbers made of non-fibrous, non-abrasive materials with non-polluting, almost closed and optically attractive surfaces. MPA structures have played an important part in a long-standing and on-going effort at IBP to establish novel Alternative Fibreless Absorber (ALFA) tools for a better noise control and acoustic comfort.
基金supported by research grants from the Malaysian Ministry ofHigher Education (MOHE), FRGS/1/2019/TK07/UMS/03/1 and Universiti Malaysia Sabah (UMS),SDK0121-2019.
文摘This paper presents a detailed preliminary assessment of load consumption and solar power potential at the Eco-Tourism Centre of Liogu Ku Silou-Silou(EPLISSI),Kota Belud,Sabah.This initial investigation assessed the feasibility of an off-grid solar PV system at EPLISSI with a suitable solar panel system for project installation and commissioning purposes.Due to the absence of an electrical grid and power supply,no pre-existing electrical appliances could be found in EPLISSI.Hence,an excel-based software,the ESCoBox,was used to produce the load profiles.The input data for this software came from a list of required electrical appliances(LED lights,fans,and phone chargers)and the historical frequency of visitors to EPLISSI.Meanwhile,to assess the solar power potential at EPLISSI,an online simulator known as Global Solar Atlas version 2.3 or GSA 2.3 was used.As an input for the GSA 2.3,the initial solar panel system capacity was set for 0.5 kWp,and then an increment of 0.1 kWp was entered until specific criteria were met.The selection of the suitable size is made when the system can satisfy the daily total average load demand and a specific load fulfillment demand.As a result,it was found that the site requires a total average demand and a total peak demand of 4.60 and 11.87 kWh/day,respectively.From the GSA 2.3 generated report,an off-grid solar PV system with the capacity of 2.50 kWp solar PV can satisfy the daily total average load demand of this area,where the average PV energy output is within the range of between 7.74–9.80 kWh/day or an average of 8.72 kWh/day.In conclusion,this preliminary assessment indicates that installing an off-grid solar PV system in this area is possible.
文摘This paper proposes a sliding mode controller based on robust model reference adaptive proportional-integral(RMRA-PI)control for a stand-alone voltage source inverter(SA-VSI).The proposed controller has two control loops where the coefficients of PI controller are regulated by the adaptive sliding law.This method is used to regulate the output voltage of the inverter under different load conditions and uncertainty,and adapts the output to the reference model to reduce the total harmonic distortion(THD).In this paper,the stability of the proposed controller is proven by using Lyapunov's theory and Barbalet’s lemma.The proposed controller performs well in voltage regulation such as low THD under sudden load change and uncertainty.Also,the results of the proposed controller are compared with PI controller to show the effectiveness of the presented control system.