The energy sector in the Gambia is entirely dependent on imported petroleum products for electricity generation. The country is not only vulnerable to global oil market disruptions but also has an unstable electricity supply system. As of 2020, a huge portion of the country’s electricity demand remains unsatisfied. Following recent government intervention to improve the energy system, this paper examined the optimal capacity expansion planning using the open-source energy modelling system (OSeMOSYS) on a time horizon of thirty years, (2020-2050). The three scenarios studied include the business as usual (BAU), which reflects the continuation with the existing power generation pattern, the second scenario (roadmap) aligns with the Gambia’s strategic electricity roadmap (2021-2040) and the third scenario considered high renewable penetration in the energy mix. Contrary to policy makers expectations, renewables accounted for only 19.2% of electricity generation in the roadmap by 2030 and 11% by 2050. CO2 emission in 2050 reduced by 31% in the roadmap scenario and 71% in the new scenario. The global cost of the new scenario is 29% more expensive than the roadmap scenario but becomes more competitive than the roadmap in terms of energy cost when the capital investment is fully subsidised in all scenarios.
{"title":"LONGTERM OPTIMIZATION MODEL FOR THE GAMBIA’S ENERGY TRANSITION","authors":"Moses S. Bass, A. López-Agüera","doi":"10.24084/repqj21.412","DOIUrl":"https://doi.org/10.24084/repqj21.412","url":null,"abstract":"The energy sector in the Gambia is entirely dependent on imported petroleum products for electricity generation. The country is not only vulnerable to global oil market disruptions but also has an unstable electricity supply system. As of 2020, a huge portion of the country’s electricity demand remains unsatisfied. Following recent government intervention to improve the energy system, this paper examined the optimal capacity expansion planning using the open-source energy modelling system (OSeMOSYS) on a time horizon of thirty years, (2020-2050). The three scenarios studied include the business as usual (BAU), which reflects the continuation with the existing power generation pattern, the second scenario (roadmap) aligns with the Gambia’s strategic electricity roadmap (2021-2040) and the third scenario considered high renewable penetration in the energy mix. Contrary to policy makers expectations, renewables accounted for only 19.2% of electricity generation in the roadmap by 2030 and 11% by 2050. CO2 emission in 2050 reduced by 31% in the roadmap scenario and 71% in the new scenario. The global cost of the new scenario is 29% more expensive than the roadmap scenario but becomes more competitive than the roadmap in terms of energy cost when the capital investment is fully subsidised in all scenarios.","PeriodicalId":21076,"journal":{"name":"Renewable Energy and Power Quality Journal","volume":"11 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78581229","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}
J. Alan Calderón, Julio C. Tafur S., E. Benjamín Barriga, J. Alencastre, Alex Quispe, Alan Ccarita
The vibration measurement of flows in transient or steady-state is a very complicated task. Moreover, to correlate it with a temperature process is quite important according to get information regarding molecular kinetic energy of thermal sources (such as flow measurement used in cleaning tasks) according to achieve heating transfer information of a thermal process. However, there is a trouble concerning the transduction stage in the measurement while it is not a transducer designed algorithm as a consequence of a mathematical model, which correlates the calibration data with the theoretical model of the heating/vibration transfer. For this reason, in this research is proposed intelligent sensors/transducers, which are based on Anodic Aluminium Oxide (AAO) and a mathematical procedure of the measurement instrumentation according to adaptive coefficients in the Modulating Functions strategies analysis and getting optimal measurements. In this research is explained and analysed the temperature measurement process and the transduction process as the strict correlation of the calibration of the temperature/vibration sensor. For this reason, there were evaluated different transducers and the temperature/vibration reference for the calibration. The based on nanostructures temperature sensors are designed by specific and complex procedures according to achieve quite operation range, robustness and precision. Moreover, the transduction can be obtained through different electrical answer variables such as voltage, electrical current or capacitance and possible to send by wireless mechanisms and protocols to the main control system. Therefore, the evaluation of the designed advanced sensor performance was achieved by the vibration and temperature measurement of the water surface of a ultrasound washing machine, for which the designed sensor enhances energy-saving of the washing process.
{"title":"Modulating Functions Analysis For Wireless Data Transmission Because Of Advanced Sensors In Energy-Saving Process Of Washing","authors":"J. Alan Calderón, Julio C. Tafur S., E. Benjamín Barriga, J. Alencastre, Alex Quispe, Alan Ccarita","doi":"10.24084/repqj21.453","DOIUrl":"https://doi.org/10.24084/repqj21.453","url":null,"abstract":"The vibration measurement of flows in transient or steady-state is a very complicated task. Moreover, to correlate it with a temperature process is quite important according to get information regarding molecular kinetic energy of thermal sources (such as flow measurement used in cleaning tasks) according to achieve heating transfer information of a thermal process. However, there is a trouble concerning the transduction stage in the measurement while it is not a transducer designed algorithm as a consequence of a mathematical model, which correlates the calibration data with the theoretical model of the heating/vibration transfer. For this reason, in this research is proposed intelligent sensors/transducers, which are based on Anodic Aluminium Oxide (AAO) and a mathematical procedure of the measurement instrumentation according to adaptive coefficients in the Modulating Functions strategies analysis and getting optimal measurements. In this research is explained and analysed the temperature measurement process and the transduction process as the strict correlation of the calibration of the temperature/vibration sensor. For this reason, there were evaluated different transducers and the temperature/vibration reference for the calibration. The based on nanostructures temperature sensors are designed by specific and complex procedures according to achieve quite operation range, robustness and precision. Moreover, the transduction can be obtained through different electrical answer variables such as voltage, electrical current or capacitance and possible to send by wireless mechanisms and protocols to the main control system. Therefore, the evaluation of the designed advanced sensor performance was achieved by the vibration and temperature measurement of the water surface of a ultrasound washing machine, for which the designed sensor enhances energy-saving of the washing process.","PeriodicalId":21076,"journal":{"name":"Renewable Energy and Power Quality Journal","volume":"150 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85611870","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}
E.P. Simonetti, S. Simonetti, L. Ribeiro, D. Simonetti
he voltage profile of low voltage distribution systems must be in accordance to national regulations, usually given by a range in which voltage needs to be. Along a day, usually voltage fluctuates according to load characteristics, especially power level and power factor, and in some situations can overpass minimum acceptable values. This paper studies the influence of the power factor measurement point governing a DSTATCOM, over the feeder voltage profile. By simulation, it was saw that connecting the D-STATCOM at the end of the system, but correcting power factor saw by the initial pole, a better voltage compliance is obtained.
{"title":"STATCOM Effect on Voltage Profile of a Distributed Network Considering Two Different Measurement Positions","authors":"E.P. Simonetti, S. Simonetti, L. Ribeiro, D. Simonetti","doi":"10.24084/repqj21.380","DOIUrl":"https://doi.org/10.24084/repqj21.380","url":null,"abstract":"he voltage profile of low voltage distribution systems must be in accordance to national regulations, usually given by a range in which voltage needs to be. Along a day, usually voltage fluctuates according to load characteristics, especially power level and power factor, and in some situations can overpass minimum acceptable values. This paper studies the influence of the power factor measurement point governing a DSTATCOM, over the feeder voltage profile. By simulation, it was saw that connecting the D-STATCOM at the end of the system, but correcting power factor saw by the initial pole, a better voltage compliance is obtained.","PeriodicalId":21076,"journal":{"name":"Renewable Energy and Power Quality Journal","volume":"37 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90942061","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}
Ever increasing demands for renewable energy sources are the driving force for the development of waste management technologies such as anaerobic digestion (AD) technology. For AD process understanding and optimization the numerical simulations provide a useful tool. Therefore, in this work, the main attention is focused on the development of an efficient and stable optimization approach. The optimization procedure is coupled with a suitable mechanistically inspired selfdeveloped BioModel. For BioModel calibration, a special procedure was developed which incorporates the used BioModel, a sensitivity analysis, and a gradient-based optimization algorithm. The results of numerical simulation, obtained by the AD of various animal manures in a batch lab-scale bioreactor, confirm the reliability of BioModel and the efficiency of the presented calibration procedure. Furthermore, the results of AD process optimization show that the biogas quantity and quality as well as energy used up for bioreactor heating can be improved essentially when amount of added bacteria, temperature and pH values are optimized properly.
{"title":"Modeling and optimization of biogas production in a batch bioreactor","authors":"Tina Kegl, E. Torres-Jiménez","doi":"10.24084/repqj21.319","DOIUrl":"https://doi.org/10.24084/repqj21.319","url":null,"abstract":"Ever increasing demands for renewable energy sources are the driving force for the development of waste management technologies such as anaerobic digestion (AD) technology. For AD process understanding and optimization the numerical simulations provide a useful tool. Therefore, in this work, the main attention is focused on the development of an efficient and stable optimization approach. The optimization procedure is coupled with a suitable mechanistically inspired selfdeveloped BioModel. For BioModel calibration, a special procedure was developed which incorporates the used BioModel, a sensitivity analysis, and a gradient-based optimization algorithm. The results of numerical simulation, obtained by the AD of various animal manures in a batch lab-scale bioreactor, confirm the reliability of BioModel and the efficiency of the presented calibration procedure. Furthermore, the results of AD process optimization show that the biogas quantity and quality as well as energy used up for bioreactor heating can be improved essentially when amount of added bacteria, temperature and pH values are optimized properly.","PeriodicalId":21076,"journal":{"name":"Renewable Energy and Power Quality Journal","volume":"20 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91055819","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}
Malena Potesta González, Roberto Martínez Pérez, Andrés Meana Fernández, Juan M. González-Caballín Sánchez, Francisco J. Rubio Serrano, A. J. Gutiérrez Trashorras
Nowadays, higher ambient temperatures and water scarcity, primarily due to climate change, represent a challenge for the refrigeration systems of traditional thermodynamic power cycles. The novel Hygroscopic Cycle Technology arises as a solution to mitigate those drawbacks by means of hygroscopic compounds, which lead to a condensation process by absorption in a mixing chamber, called absorber. Consequently, heat rejection can be achieved at higher cold sink temperatures in a closed loop, avoiding water consumption. In this work, the influence of the concentration of the hygroscopic salt LiBr in the condensation process inside the absorber, key element of the cycle, has been analyzed with EES software. The analysis is divided into very low (0% to 0.01%) and low (0.01% to 5%) concentrations of LiBr-H2O solutions. Absolute pressure at the absorber ranges between 3 kPa and 21 kPa. Results show that properties of very low concentration mixtures can be approximated to those of pure water, showing errors lower than 0.11%. As concentration rises from 0.01 to 5 % specific enthalpy decreases, leading to lower consumption of the refrigeration system of the cycle.
{"title":"Analytical study of the absorber performance of a Hygroscopic cycle for low concentrations of LiBr solutions","authors":"Malena Potesta González, Roberto Martínez Pérez, Andrés Meana Fernández, Juan M. González-Caballín Sánchez, Francisco J. Rubio Serrano, A. J. Gutiérrez Trashorras","doi":"10.24084/repqj21.338","DOIUrl":"https://doi.org/10.24084/repqj21.338","url":null,"abstract":"Nowadays, higher ambient temperatures and water scarcity, primarily due to climate change, represent a challenge for the refrigeration systems of traditional thermodynamic power cycles. The novel Hygroscopic Cycle Technology arises as a solution to mitigate those drawbacks by means of hygroscopic compounds, which lead to a condensation process by absorption in a mixing chamber, called absorber. Consequently, heat rejection can be achieved at higher cold sink temperatures in a closed loop, avoiding water consumption. In this work, the influence of the concentration of the hygroscopic salt LiBr in the condensation process inside the absorber, key element of the cycle, has been analyzed with EES software. The analysis is divided into very low (0% to 0.01%) and low (0.01% to 5%) concentrations of LiBr-H2O solutions. Absolute pressure at the absorber ranges between 3 kPa and 21 kPa. Results show that properties of very low concentration mixtures can be approximated to those of pure water, showing errors lower than 0.11%. As concentration rises from 0.01 to 5 % specific enthalpy decreases, leading to lower consumption of the refrigeration system of the cycle.","PeriodicalId":21076,"journal":{"name":"Renewable Energy and Power Quality Journal","volume":"57 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75910518","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}
This paper presents a case study for rooftop PV system mounted on corporate building of Saudi Electricity Company (SEC) HQ with a capacity of 277KWp. By collecting the generation data of the PV system along with the electrical loads of the building for the year 2021, the data showed that the amount of energy produced from the system, which was directly fed to the loads is about 404.8 MWh. Accordingly, the contribution rate of the PV system generation to energy consumption was calculated to be about 15.7% of the loads of the entire building, which totaled about 2547.8 MWh. The study showed that there is an excess of electrical energy produced from these solar panels. The system is programmed through the inverter to keep the production of solar panels equal or less than the electrical loads which is connected to due to the absence of the regulation for connecting PV systems with the electric grid at that time. The excess energy of PV generation was calculated as 478.5 MWh. Hence, the surplus energy is 69.1 MWh representing approximately 15% of the calculated PV generation. The study covered the economic perspective for the system by estimating the levelized cost of energy and payback period to be LCOE= 0.33 SR/kWh = 0.088 USD/kWh and Payback period= 23.9 years respectively.
{"title":"Efficient utilization of solar PV for corporate building in Riyadh, Saudi Arabia","authors":"Fahad Saeed Alharthi, A. Alamoud","doi":"10.24084/repqj21.232","DOIUrl":"https://doi.org/10.24084/repqj21.232","url":null,"abstract":"This paper presents a case study for rooftop PV system mounted on corporate building of Saudi Electricity Company (SEC) HQ with a capacity of 277KWp. By collecting the generation data of the PV system along with the electrical loads of the building for the year 2021, the data showed that the amount of energy produced from the system, which was directly fed to the loads is about 404.8 MWh. Accordingly, the contribution rate of the PV system generation to energy consumption was calculated to be about 15.7% of the loads of the entire building, which totaled about 2547.8 MWh. The study showed that there is an excess of electrical energy produced from these solar panels. The system is programmed through the inverter to keep the production of solar panels equal or less than the electrical loads which is connected to due to the absence of the regulation for connecting PV systems with the electric grid at that time. The excess energy of PV generation was calculated as 478.5 MWh. Hence, the surplus energy is 69.1 MWh representing approximately 15% of the calculated PV generation. The study covered the economic perspective for the system by estimating the levelized cost of energy and payback period to be LCOE= 0.33 SR/kWh = 0.088 USD/kWh and Payback period= 23.9 years respectively.","PeriodicalId":21076,"journal":{"name":"Renewable Energy and Power Quality Journal","volume":"13 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81012630","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}
A. Ramos, A. J. Batista, R. Leborgne, E. G. Domingues, W. Calixto
An analysis of the distributed generation (DG) and fault impedance on studies of voltage sags caused by system faults is presented on domain of frequency. The simulation of 62 case studies of phase-to-ground faults on 13.8, 69, 138 and 230 kV transmission lines were performed and the voltage of a 380 V sensitive industrial busbar client was monitored. These lines are part of the electrical system of the city of Goiania, Brazil. For each case study, different fault positions and impedance fault were simulated by considering different DG levels connected to the consumer busbar. Long-term simulation scenarios were obtained by the Monte Carlo method and analyzed based on their cumulative distribution functions and probability density curves of voltage sags. This is one major contribution of this work.
{"title":"A First Approach on the Impact of Distributed Generation and Fault Impedance on Studies on domain of frequency of Voltage Sags","authors":"A. Ramos, A. J. Batista, R. Leborgne, E. G. Domingues, W. Calixto","doi":"10.24084/repqj21.311","DOIUrl":"https://doi.org/10.24084/repqj21.311","url":null,"abstract":"An analysis of the distributed generation (DG) and fault impedance on studies of voltage sags caused by system faults is presented on domain of frequency. The simulation of 62 case studies of phase-to-ground faults on 13.8, 69, 138 and 230 kV transmission lines were performed and the voltage of a 380 V sensitive industrial busbar client was monitored. These lines are part of the electrical system of the city of Goiania, Brazil. For each case study, different fault positions and impedance fault were simulated by considering different DG levels connected to the consumer busbar. Long-term simulation scenarios were obtained by the Monte Carlo method and analyzed based on their cumulative distribution functions and probability density curves of voltage sags. This is one major contribution of this work.","PeriodicalId":21076,"journal":{"name":"Renewable Energy and Power Quality Journal","volume":"29 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77223762","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}
The paper deals with optimisation of energy storage systems technology for emergency shelters (tiny houses) for Ukrainian War refugees. Huge number of Ukrainian citizens lost their houses or had to leave their homes. These refugees increase population in the rest of Ukraine what escalates problems with accommodation and integration into native communities. Emergency living in communal properties has unpleasant influence on the communities and is acceptable just for limited period. It becomes important to build new quarters or urban areas using cheap but energy efficient technologies. This research is based on real shelter project realised between Ukrainian non-government organisation Synergy and German development agency weChange. Main task of this paper is optimisation of energy strategy in community consisting of hundreds or thousands units and called shelter city. Solution of one single tiny house with implemented RES is task deeply evaluated in several projects, but we must take into account cooperation of large amount of units to limit total influence on Ukrainian distribution and transmission networks. Ukrainian infrastructure was already in unpleasant state before war and new connections of these consumers would dramatically overload existing infrastructure. This task is yet more complicated in nowadays war conditions, where crucial parts of the networks are being repeatedly damaged. From this point of view, it is essential to design the shelter community like consumer o prosumer with perfectly balanced load and production chart. The shelters should be built in passive standard to achieve minimal acquisition and operational costs. Also very efficient but cheap energy storage system must be integrated on the level of particular shelter or entire shelter city. Influence of various battery technologies using different coupling schemes is being discussed. AC coupling, DC coupling with intermediate circuit or PV generator circuit are tuned for specific load charts to optimise the influence on distribution network.
{"title":"Battery storage technology optimisation for Ukrainian War Refugees Emergency Shelters","authors":"M. Bělík","doi":"10.24084/repqj21.350","DOIUrl":"https://doi.org/10.24084/repqj21.350","url":null,"abstract":"The paper deals with optimisation of energy storage systems technology for emergency shelters (tiny houses) for Ukrainian War refugees. Huge number of Ukrainian citizens lost their houses or had to leave their homes. These refugees increase population in the rest of Ukraine what escalates problems with accommodation and integration into native communities. Emergency living in communal properties has unpleasant influence on the communities and is acceptable just for limited period. It becomes important to build new quarters or urban areas using cheap but energy efficient technologies. This research is based on real shelter project realised between Ukrainian non-government organisation Synergy and German development agency weChange. Main task of this paper is optimisation of energy strategy in community consisting of hundreds or thousands units and called shelter city. Solution of one single tiny house with implemented RES is task deeply evaluated in several projects, but we must take into account cooperation of large amount of units to limit total influence on Ukrainian distribution and transmission networks. Ukrainian infrastructure was already in unpleasant state before war and new connections of these consumers would dramatically overload existing infrastructure. This task is yet more complicated in nowadays war conditions, where crucial parts of the networks are being repeatedly damaged. From this point of view, it is essential to design the shelter community like consumer o prosumer with perfectly balanced load and production chart. The shelters should be built in passive standard to achieve minimal acquisition and operational costs. Also very efficient but cheap energy storage system must be integrated on the level of particular shelter or entire shelter city. Influence of various battery technologies using different coupling schemes is being discussed. AC coupling, DC coupling with intermediate circuit or PV generator circuit are tuned for specific load charts to optimise the influence on distribution network.","PeriodicalId":21076,"journal":{"name":"Renewable Energy and Power Quality Journal","volume":"70 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77455912","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}
This paper proposes the use of linear-assisted switching power converters in the context of single-inductor dual-output (SIDO) for microgrids (MG) applications. By combining a DC/DC ripple-controlled switching power converter with the respective voltage linear regulators at each output, improved performance in terms of load and line regulations is obtained. To achieve that aim, a current-steering switching policy is proposed, together with a resource-aware circuit implementation. The ripple-based hysteretic control results in variable switching frequency to guarantee critical conduction mode (boundary of CCM and DCM).
{"title":"On Single-Input Dual-Output (SIDO) DC/DC Multi-Port Converters for DC Microgrid Applications","authors":"H. Martínez-García, Encarna García-Vílchez","doi":"10.24084/repqj21.438","DOIUrl":"https://doi.org/10.24084/repqj21.438","url":null,"abstract":"This paper proposes the use of linear-assisted switching power converters in the context of single-inductor dual-output (SIDO) for microgrids (MG) applications. By combining a DC/DC ripple-controlled switching power converter with the respective voltage linear regulators at each output, improved performance in terms of load and line regulations is obtained. To achieve that aim, a current-steering switching policy is proposed, together with a resource-aware circuit implementation. The ripple-based hysteretic control results in variable switching frequency to guarantee critical conduction mode (boundary of CCM and DCM).","PeriodicalId":21076,"journal":{"name":"Renewable Energy and Power Quality Journal","volume":"70 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77456540","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}
Lluc Crespí-Castañer, M. Roca, J. Rosselló, Lluís Juncosa, Vicente Canals
. A widespread problem of the electricity distribution system is determining to which phase a consumer is connected. Generally, utility companies did not record the distribution of the phases over time, which is essential to address the problem of unbalanced voltage distribution networks. In addition, manual phase identification is not feasible due to its high cost. The massive deployment of smart meters allowed periodic readings of energy consumption, voltage, current, etc. Out of this large amount of data, several techniques based on machine learning have emerged, addressing the problem of phase identification automatically while maintaining the existing infrastructure. Hence, phase identification is essential for developing smart-grid solutions. In the present work, we applied an unsupervised machine-learning technique that allows the classification of the time-voltage series recorded by the smart meters of a low-voltage three-phase radial distribution network located in the Balearic Islands (Spain). The results show that there is a correlation between the time series of the feeder voltage and the consumer meters. The proposed method reached a 100% success rate in the case study. In addition, the results obtained open the way to deploy a new grid configuration to minimize the load imbalance.
{"title":"Phase Identification in Smart Grids – Case Study","authors":"Lluc Crespí-Castañer, M. Roca, J. Rosselló, Lluís Juncosa, Vicente Canals","doi":"10.24084/repqj21.256","DOIUrl":"https://doi.org/10.24084/repqj21.256","url":null,"abstract":". A widespread problem of the electricity distribution system is determining to which phase a consumer is connected. Generally, utility companies did not record the distribution of the phases over time, which is essential to address the problem of unbalanced voltage distribution networks. In addition, manual phase identification is not feasible due to its high cost. The massive deployment of smart meters allowed periodic readings of energy consumption, voltage, current, etc. Out of this large amount of data, several techniques based on machine learning have emerged, addressing the problem of phase identification automatically while maintaining the existing infrastructure. Hence, phase identification is essential for developing smart-grid solutions. In the present work, we applied an unsupervised machine-learning technique that allows the classification of the time-voltage series recorded by the smart meters of a low-voltage three-phase radial distribution network located in the Balearic Islands (Spain). The results show that there is a correlation between the time series of the feeder voltage and the consumer meters. The proposed method reached a 100% success rate in the case study. In addition, the results obtained open the way to deploy a new grid configuration to minimize the load imbalance.","PeriodicalId":21076,"journal":{"name":"Renewable Energy and Power Quality Journal","volume":"6 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81169453","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}
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