As fossil fuel stocks are being depleted, alternative sources of energy must be explored. Consequently, traditional thermal power plants must coexist with renewable resources, such as wind, solar, and hydro units, and all-day planning and operation techniques are necessary to safeguard nature while meeting the current demand. The fundamental components of contemporary power systems are the simultaneous decrease in generation costs and increase in the available transfer capacity (ATC) of current systems. Thermal units are linked to sources of renewable energy such as hydro, wind, and solar power, and are set up to run for 24 h. By contrast, new research reports that various chaotic maps are merged with various existing optimization methodologies to obtain better results than those without the inclusion of chaos. Chaos seems to increase the performance and convergence properties of existing optimization approaches. In this study, selfish animal tendencies, mathematically represented as selfish herd optimizers, were hybridized with chaotic phenomena and used to improve ATC and/or reduce generation costs, creating a multi-objective optimization problem. To evaluate the performance of the proposed hybridized optimization technique, an optimal power flow-based ATC was enforced under various hydro-thermal-solar-wind conditions, that is, the renewable energy source-thermal scheduling concept, on IEEE 9-bus, IEEE 39-bus, and Indian Northern Region Power Grid 246-bus test systems. The findings show that the proposed technique outperforms existing well-established optimization strategies.
{"title":"Calculation of Available Transfer Capability Using Hybrid Chaotic Selfish Herd Optimizer and 24 Hours RES-thermal Scheduling","authors":"Kingsuk Majumdar;Provas Kumar Roy;Subrata Banerjee","doi":"10.23919/CJEE.2023.000032","DOIUrl":"https://doi.org/10.23919/CJEE.2023.000032","url":null,"abstract":"As fossil fuel stocks are being depleted, alternative sources of energy must be explored. Consequently, traditional thermal power plants must coexist with renewable resources, such as wind, solar, and hydro units, and all-day planning and operation techniques are necessary to safeguard nature while meeting the current demand. The fundamental components of contemporary power systems are the simultaneous decrease in generation costs and increase in the available transfer capacity (ATC) of current systems. Thermal units are linked to sources of renewable energy such as hydro, wind, and solar power, and are set up to run for 24 h. By contrast, new research reports that various chaotic maps are merged with various existing optimization methodologies to obtain better results than those without the inclusion of chaos. Chaos seems to increase the performance and convergence properties of existing optimization approaches. In this study, selfish animal tendencies, mathematically represented as selfish herd optimizers, were hybridized with chaotic phenomena and used to improve ATC and/or reduce generation costs, creating a multi-objective optimization problem. To evaluate the performance of the proposed hybridized optimization technique, an optimal power flow-based ATC was enforced under various hydro-thermal-solar-wind conditions, that is, the renewable energy source-thermal scheduling concept, on IEEE 9-bus, IEEE 39-bus, and Indian Northern Region Power Grid 246-bus test systems. The findings show that the proposed technique outperforms existing well-established optimization strategies.","PeriodicalId":36428,"journal":{"name":"Chinese Journal of Electrical Engineering","volume":"9 4","pages":"54-72"},"PeriodicalIF":0.0,"publicationDate":"2023-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10345655","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139109366","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-01DOI: 10.23919/CJEE.2023.000031
Youzhen Wu;Jianxiao Wang;Yiyang Song;Yunyun Xie
In power grids, the frequency is increasing of extreme accidents which have a low probability but high risk such as natural disasters and deliberate attacks. This has sparked discussions on the resilience of power grids. Energy-storage systems (ESSs) are critical for enhancing the resilience of power grids. ESSs, with their mechanism of flexible charging and discharging, adjust energy usage as needed during disasters, thereby mitigating the impact on the grid and enhancing security and resilience. This, in turn, ensures the power system's stable operation. Currently, there is limited systematic research quantifying the economic value of energy storage in resilience scenarios. Therefore, a model and methodology were proposed to quantify the value of energy storage systems for enhancing grid resilience during extreme events. A two-stage stochastic optimization mathematical model was developed. The first stage involves pre-deployment based on day-ahead expectations, and the second stage involves simulating potential failure scenarios through real-time scheduling. Considering the temporal dimension, the energy storage systems with flexible regulation capabilities was used as emergency power sources to reduce occurrences of load-shedding. Here, a novel index was proposed that quantifies the resilience value of energy storage as the economic value of energy storage per unit of capacity, as reflected in the emergency dispatch model. This index helps determine the balance between the energy storage investment cost and resilience value. Finally, an IEEE-30 node transmission system was used to verify the feasibility and effectiveness of the proposed method. The findings revealed a significant improvement in the resilience value, with a 23.49% increase observed when energy storage systems were implemented compared to the scenario without energy storage systems. The optimal capacity configurations for the flywheel, lithium-ion batteries, and pumped hydro storage were 10 MW, 11 MW, and 12 MW, respectively, highlight their potential to maximize value in experimental system.
{"title":"Resilience-Oriented Valuation for Energy Storage Amidst Extreme Events","authors":"Youzhen Wu;Jianxiao Wang;Yiyang Song;Yunyun Xie","doi":"10.23919/CJEE.2023.000031","DOIUrl":"https://doi.org/10.23919/CJEE.2023.000031","url":null,"abstract":"In power grids, the frequency is increasing of extreme accidents which have a low probability but high risk such as natural disasters and deliberate attacks. This has sparked discussions on the resilience of power grids. Energy-storage systems (ESSs) are critical for enhancing the resilience of power grids. ESSs, with their mechanism of flexible charging and discharging, adjust energy usage as needed during disasters, thereby mitigating the impact on the grid and enhancing security and resilience. This, in turn, ensures the power system's stable operation. Currently, there is limited systematic research quantifying the economic value of energy storage in resilience scenarios. Therefore, a model and methodology were proposed to quantify the value of energy storage systems for enhancing grid resilience during extreme events. A two-stage stochastic optimization mathematical model was developed. The first stage involves pre-deployment based on day-ahead expectations, and the second stage involves simulating potential failure scenarios through real-time scheduling. Considering the temporal dimension, the energy storage systems with flexible regulation capabilities was used as emergency power sources to reduce occurrences of load-shedding. Here, a novel index was proposed that quantifies the resilience value of energy storage as the economic value of energy storage per unit of capacity, as reflected in the emergency dispatch model. This index helps determine the balance between the energy storage investment cost and resilience value. Finally, an IEEE-30 node transmission system was used to verify the feasibility and effectiveness of the proposed method. The findings revealed a significant improvement in the resilience value, with a 23.49% increase observed when energy storage systems were implemented compared to the scenario without energy storage systems. The optimal capacity configurations for the flywheel, lithium-ion batteries, and pumped hydro storage were 10 MW, 11 MW, and 12 MW, respectively, highlight their potential to maximize value in experimental system.","PeriodicalId":36428,"journal":{"name":"Chinese Journal of Electrical Engineering","volume":"9 3","pages":"15-25"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/iel7/7873788/10272329/10272567.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49939877","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-01DOI: 10.23919/CJEE.2023.000035
With the increasing concern about climate change, environmental pollution, and sustainable development, the energy system is evolving towards a low-carbon form powered by a large share of renewable energy. Renewable generation from wind and solar is intermittent and volatile, posing great challenges to the secure and economical operation of power systems which requires simultaneous balance between power demand and supply. In this regard, various energy storage, including battery, pumped storage, compressed-air storage, flywheel, supper-capacitor, etc., are recognized as indispensable technologies to deal with the intermittency from renewables and facilitate the low-carbon transition of power systems. Energy storage can be implemented in different parts of the power supply chain from generation-side to grid-side and demand-side, and can benefit the power system operation in multiple time scales from seasonal energy balance to near-real-time stability control.
{"title":"Editorial for the Special Issue on Emerging Technology and Advanced Application of Energy Storage in Low-Carbon Power Systems","authors":"","doi":"10.23919/CJEE.2023.000035","DOIUrl":"https://doi.org/10.23919/CJEE.2023.000035","url":null,"abstract":"With the increasing concern about climate change, environmental pollution, and sustainable development, the energy system is evolving towards a low-carbon form powered by a large share of renewable energy. Renewable generation from wind and solar is intermittent and volatile, posing great challenges to the secure and economical operation of power systems which requires simultaneous balance between power demand and supply. In this regard, various energy storage, including battery, pumped storage, compressed-air storage, flywheel, supper-capacitor, etc., are recognized as indispensable technologies to deal with the intermittency from renewables and facilitate the low-carbon transition of power systems. Energy storage can be implemented in different parts of the power supply chain from generation-side to grid-side and demand-side, and can benefit the power system operation in multiple time scales from seasonal energy balance to near-real-time stability control.","PeriodicalId":36428,"journal":{"name":"Chinese Journal of Electrical Engineering","volume":"9 3","pages":"1-2"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/iel7/7873788/10272329/10272330.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49939875","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-01DOI: 10.23919/CJEE.2023.000033
Bo Li;Chunjie Qin;Ruotao Yu;Wei Dai;Mengjun Shen;Ziming Ma;Jianxiao Wang
Long-term storage (LTS) can provide various services to address seasonal fluctuations in variable renewable energy by reducing energy curtailment. However, long-term unit commitment (UC) with LTS involves mixed-integer programming with large-scale coupling constraints between consecutive intervals (state-of-charge (SOC) constraint of LTS, ramping rate, and minimum up/down time constraints of thermal units), resulting in a significant computational burden. Herein, an iterative-based fast solution method is proposed to solve the long-term UC with LTS. First, the UC with coupling constraints is split into several sub problems that can be solved in parallel. Second, the solutions of the sub problems are adjusted to obtain a feasible solution that satisfies the coupling constraints. Third, a decoupling method for long-term time-series coupling constraints is proposed to determine the global optimization of the SOC of the LTS. The price-arbitrage model of the LTS determines the SOC boundary of the LTS for each sub problem. Finally, the sub problem with the SOC boundary of the LTS is iteratively solved independently. The proposed method was verified using a modified IEEE 24-bus system. The results showed that the computation time of the unit combination problem can be reduced by 97.8%, with a relative error of 3.62%.
{"title":"Fast Solution Method for the Large-Scale Unit Commitment Problem with Long-Term Storage","authors":"Bo Li;Chunjie Qin;Ruotao Yu;Wei Dai;Mengjun Shen;Ziming Ma;Jianxiao Wang","doi":"10.23919/CJEE.2023.000033","DOIUrl":"https://doi.org/10.23919/CJEE.2023.000033","url":null,"abstract":"Long-term storage (LTS) can provide various services to address seasonal fluctuations in variable renewable energy by reducing energy curtailment. However, long-term unit commitment (UC) with LTS involves mixed-integer programming with large-scale coupling constraints between consecutive intervals (state-of-charge (SOC) constraint of LTS, ramping rate, and minimum up/down time constraints of thermal units), resulting in a significant computational burden. Herein, an iterative-based fast solution method is proposed to solve the long-term UC with LTS. First, the UC with coupling constraints is split into several sub problems that can be solved in parallel. Second, the solutions of the sub problems are adjusted to obtain a feasible solution that satisfies the coupling constraints. Third, a decoupling method for long-term time-series coupling constraints is proposed to determine the global optimization of the SOC of the LTS. The price-arbitrage model of the LTS determines the SOC boundary of the LTS for each sub problem. Finally, the sub problem with the SOC boundary of the LTS is iteratively solved independently. The proposed method was verified using a modified IEEE 24-bus system. The results showed that the computation time of the unit combination problem can be reduced by 97.8%, with a relative error of 3.62%.","PeriodicalId":36428,"journal":{"name":"Chinese Journal of Electrical Engineering","volume":"9 3","pages":"39-49"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/iel7/7873788/10272329/10272564.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49976318","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A comparison of two modular linear permanent-magnet vernier (LPMV) machines is presented. A modular LPMV machine with a partitioned primary, which can significantly improve the modulation effect, is proposed. Benefitting from the partition design, the space conflict between the permanent magnet (PM) and the armature magnetic field is relieved. First, the topologies of modular LPMV machines with and without a partitioned primary are presented. Then, the effect of the partitioned primary on the modular LPMV machine is analyzed using flux modulation theory. Moreover, analytical expressions for the trapezoidal permeance are derived. In addition, the harmonic components, back electromotive forces, and thrust forces of the machines with and without the partitioned primary are comparatively analyzed. The results reveal that the thrust force density of the LPMV machine with a partitioned primary is increased by 32.3%. Finally, experiments are performed on a prototype machine for validation.
{"title":"Quantitative Comparison of Modular Linear Permanent Magnet Vernier Machines with and Without Partitioned Primary","authors":"Yunpeng Xu;Jinghua Ji;Zhijian Ling;Chen Wang;Wenxiang Zhao","doi":"10.23919/CJEE.2023.000024","DOIUrl":"https://doi.org/10.23919/CJEE.2023.000024","url":null,"abstract":"A comparison of two modular linear permanent-magnet vernier (LPMV) machines is presented. A modular LPMV machine with a partitioned primary, which can significantly improve the modulation effect, is proposed. Benefitting from the partition design, the space conflict between the permanent magnet (PM) and the armature magnetic field is relieved. First, the topologies of modular LPMV machines with and without a partitioned primary are presented. Then, the effect of the partitioned primary on the modular LPMV machine is analyzed using flux modulation theory. Moreover, analytical expressions for the trapezoidal permeance are derived. In addition, the harmonic components, back electromotive forces, and thrust forces of the machines with and without the partitioned primary are comparatively analyzed. The results reveal that the thrust force density of the LPMV machine with a partitioned primary is increased by 32.3%. Finally, experiments are performed on a prototype machine for validation.","PeriodicalId":36428,"journal":{"name":"Chinese Journal of Electrical Engineering","volume":"9 3","pages":"72-83"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/iel7/7873788/10272329/10272568.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49939870","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-01DOI: 10.23919/CJEE.2023.000030
Zijie He;Guidong Zhang;Zexiang Chen;Samson S. Yu
Modern eco-friendly industries such as renewable energy systems, electric vehicles (EVs), and light-emitting diodes (LEDs) have led to technological advancements in power electronics. Switching-based power converters have limited working ranges and can cause significant harmonics and oscillations in the output voltage and current. Introducing variable inductors can help solve this problem by changing the inductance without resorting to extreme switch duty cycles. Despite their advantages, there is still a lack of comprehensive reviews of variable inductor applications in power converter design. A thorough and in-depth review of variable inductance control in power conversion is presented, including its significance, working principle, core structure, modeling method, and typical applications. Traditionally, an inductor works in its linear magnetic region; its inductance in a power converter is considered constant, and the converter operates under fixed working conditions. However, a broad range of working conditions is required for power converters in practical applications. This is typically realized by changing the duty cycles of the switches. The working principle of variable inductance is reviewed, and the application of variable inductance control in power converters is presented, which will further help power electronics researchers and engineers design flexible and resilient power converters.
{"title":"A Review of Variable-Inductor-Based Power Converters for Eco-Friendly Applications: Fundamentals, Configurations, and Applications","authors":"Zijie He;Guidong Zhang;Zexiang Chen;Samson S. Yu","doi":"10.23919/CJEE.2023.000030","DOIUrl":"https://doi.org/10.23919/CJEE.2023.000030","url":null,"abstract":"Modern eco-friendly industries such as renewable energy systems, electric vehicles (EVs), and light-emitting diodes (LEDs) have led to technological advancements in power electronics. Switching-based power converters have limited working ranges and can cause significant harmonics and oscillations in the output voltage and current. Introducing variable inductors can help solve this problem by changing the inductance without resorting to extreme switch duty cycles. Despite their advantages, there is still a lack of comprehensive reviews of variable inductor applications in power converter design. A thorough and in-depth review of variable inductance control in power conversion is presented, including its significance, working principle, core structure, modeling method, and typical applications. Traditionally, an inductor works in its linear magnetic region; its inductance in a power converter is considered constant, and the converter operates under fixed working conditions. However, a broad range of working conditions is required for power converters in practical applications. This is typically realized by changing the duty cycles of the switches. The working principle of variable inductance is reviewed, and the application of variable inductance control in power converters is presented, which will further help power electronics researchers and engineers design flexible and resilient power converters.","PeriodicalId":36428,"journal":{"name":"Chinese Journal of Electrical Engineering","volume":"9 3","pages":"50-71"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/iel7/7873788/10272329/10272566.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49939871","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-01DOI: 10.23919/CJEE.2023.000026
Krunal Shah;Abid Mansuri;Rakesh Maurya
In this study, a six-phase induction asymmetric induction motor (SPAIM) was examined, whose performance surpasses that of its three-phase counterpart, with regard to the torque density, torque pulsation, fault tolerance, power rating per inverter lag, and noise characteristics. Speed-encoder-less direct torque control (DTC) for SPAIM with virtual voltage vectors (VVVs) and a modified sliding mode observer (MSMO) are described. The SPAIM model was developed using a stationary $alpha-beta$