Pub Date : 2023-11-15DOI: 10.3389/fenrg.2023.1284076
Khursheed Aurangzeb
Analyzing and understanding the electricity consumption of end users, especially the anomalies (outliers), are vital for the planning, operation, and management of the power grid. It will help separate the group of users with unpredictable consumption behavior and then develop and train specialized deep learning models for power load forecasting or regular and non-regular users. The aim of the current work is to divide electricity customers into numerous groups based on anomalies in consumption behavior and major clusters. Successful separation of such groups of customers will provide us with two advantages. One is the increase in the accuracy of load forecasting of other users or groups of users due to their predictable consumption behavior. The second is the opportunity to develop and train specialized deep learning models for customers with highly unpredictable behaviors. The novelty of the work is the segregation of anomalous electricity users from normal/regular users based on outliers in their past power consumption behavior over a period of 92 days. Results indicate that almost 85 percent of the users in the selected residential community attribute one major cluster in their consumption behavior over a period of 3 months of data (92 days). It is also evident from the results that only a small proportion of customers, i.e., 10 out of 69 customers (15 percent), have either more than one cluster or attribute no cluster (zero clusters), which is highly important and indicates that these are the possible users who cause higher variations in power consumption of the residential community.
{"title":"Anomalies and major cluster-based grouping of electricity users for improving the forecasting performance of deep learning models","authors":"Khursheed Aurangzeb","doi":"10.3389/fenrg.2023.1284076","DOIUrl":"https://doi.org/10.3389/fenrg.2023.1284076","url":null,"abstract":"Analyzing and understanding the electricity consumption of end users, especially the anomalies (outliers), are vital for the planning, operation, and management of the power grid. It will help separate the group of users with unpredictable consumption behavior and then develop and train specialized deep learning models for power load forecasting or regular and non-regular users. The aim of the current work is to divide electricity customers into numerous groups based on anomalies in consumption behavior and major clusters. Successful separation of such groups of customers will provide us with two advantages. One is the increase in the accuracy of load forecasting of other users or groups of users due to their predictable consumption behavior. The second is the opportunity to develop and train specialized deep learning models for customers with highly unpredictable behaviors. The novelty of the work is the segregation of anomalous electricity users from normal/regular users based on outliers in their past power consumption behavior over a period of 92 days. Results indicate that almost 85 percent of the users in the selected residential community attribute one major cluster in their consumption behavior over a period of 3 months of data (92 days). It is also evident from the results that only a small proportion of customers, i.e., 10 out of 69 customers (15 percent), have either more than one cluster or attribute no cluster (zero clusters), which is highly important and indicates that these are the possible users who cause higher variations in power consumption of the residential community.","PeriodicalId":503838,"journal":{"name":"Frontiers in Energy Research","volume":"12 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139271866","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 : 2023-11-15DOI: 10.3389/fenrg.2023.1304945
Qingsheng Li, Changming Chen, Yongqing Zhu, Yunchu Wang, Chang Liu, Hongle Liang, Zhen Li, Zhaofeng Zhang, Li Yang
In the event of a major power outage in the power systems, there is an urgent need to investigate entire-process coordinated restoration strategies for the transmission systems (TSs) and distribution systems (DSs), aiming to accelerate the restoration speed of generating units, network reconfiguration, and load restoration. Furthermore, it is imperative to address the multiple uncertainties that arise during the restoration process to mitigate potential security risks associated with the restoration. Hence, an adaptive ADMM-based entire-process distributed restoration method of TSs and DSs considering CVaR is proposed in this paper. Firstly, an entire-process distributed restoration model of TSs and DSs considering CVaR is proposed to maximize the total restoration benefits of TSs and DSs. Then, an adaptive ADMM-based distributed solving algorithm for the coordinated restoration model of the TSs and DSs is introduced, which incorporates adaptive penalty parameter adjustments, leading to faster convergence compared to the standard ADMM. Finally, case studies on an improved 179-bus transmission system are employed to verify that the proposed restoration method can achieve higher restoration benefits and faster convergence speed compared to existing restoration models.
{"title":"Adaptive ADMM-based entire-process distributed restoration of transmission and distribution systems","authors":"Qingsheng Li, Changming Chen, Yongqing Zhu, Yunchu Wang, Chang Liu, Hongle Liang, Zhen Li, Zhaofeng Zhang, Li Yang","doi":"10.3389/fenrg.2023.1304945","DOIUrl":"https://doi.org/10.3389/fenrg.2023.1304945","url":null,"abstract":"In the event of a major power outage in the power systems, there is an urgent need to investigate entire-process coordinated restoration strategies for the transmission systems (TSs) and distribution systems (DSs), aiming to accelerate the restoration speed of generating units, network reconfiguration, and load restoration. Furthermore, it is imperative to address the multiple uncertainties that arise during the restoration process to mitigate potential security risks associated with the restoration. Hence, an adaptive ADMM-based entire-process distributed restoration method of TSs and DSs considering CVaR is proposed in this paper. Firstly, an entire-process distributed restoration model of TSs and DSs considering CVaR is proposed to maximize the total restoration benefits of TSs and DSs. Then, an adaptive ADMM-based distributed solving algorithm for the coordinated restoration model of the TSs and DSs is introduced, which incorporates adaptive penalty parameter adjustments, leading to faster convergence compared to the standard ADMM. Finally, case studies on an improved 179-bus transmission system are employed to verify that the proposed restoration method can achieve higher restoration benefits and faster convergence speed compared to existing restoration models.","PeriodicalId":503838,"journal":{"name":"Frontiers in Energy Research","volume":"4 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139273397","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 : 2023-11-15DOI: 10.3389/fenrg.2023.1298694
Xu Yang, Zhicheng Liu, Jin Zhu, Pei Liu, Tongzhen Wei
The research domain about the selection and design methodology of battery topology structures for energy storage systems, grounded in practical application scenarios, remains significantly underexplored. Furthermore, a substantial gap exists in the current state of research, where the majority of studies lack a comprehensive analysis of losses and reliability associated with reconfigurable battery topology structures. This paper quantitatively analyzes existing MOSFET-based topologies from three key dimensions: losses, costs, and reliability. The study aims to discern the impact of different topology structures and energy storage systems with redundant units on these three dimensions. Subsequently, while ensuring the adaptability of the topology structure, we propose a novel reconfigurable battery system topology suitable for DC microgrids, accompanied by its corresponding control strategy. Through comparative analysis with three typical topology structures, this topology structure has been validated to exhibit certain advantages in terms of losses, reliability, and costs. Lastly, the feasibility of the introduced topology structure is demonstrated through simulation using MATLAB/Simulink. Simulation results indicate that the proposed topology structure not only provides precise control of charge and discharge currents but also demonstrates excellent battery balancing capabilities.
{"title":"Loss and reliability analysis of various solid-state battery reconfiguration topologies","authors":"Xu Yang, Zhicheng Liu, Jin Zhu, Pei Liu, Tongzhen Wei","doi":"10.3389/fenrg.2023.1298694","DOIUrl":"https://doi.org/10.3389/fenrg.2023.1298694","url":null,"abstract":"The research domain about the selection and design methodology of battery topology structures for energy storage systems, grounded in practical application scenarios, remains significantly underexplored. Furthermore, a substantial gap exists in the current state of research, where the majority of studies lack a comprehensive analysis of losses and reliability associated with reconfigurable battery topology structures. This paper quantitatively analyzes existing MOSFET-based topologies from three key dimensions: losses, costs, and reliability. The study aims to discern the impact of different topology structures and energy storage systems with redundant units on these three dimensions. Subsequently, while ensuring the adaptability of the topology structure, we propose a novel reconfigurable battery system topology suitable for DC microgrids, accompanied by its corresponding control strategy. Through comparative analysis with three typical topology structures, this topology structure has been validated to exhibit certain advantages in terms of losses, reliability, and costs. Lastly, the feasibility of the introduced topology structure is demonstrated through simulation using MATLAB/Simulink. Simulation results indicate that the proposed topology structure not only provides precise control of charge and discharge currents but also demonstrates excellent battery balancing capabilities.","PeriodicalId":503838,"journal":{"name":"Frontiers in Energy Research","volume":"177 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139273734","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 : 2023-11-15DOI: 10.3389/fenrg.2023.1296957
Ning Zhou Xu, Xiang Gao, Songjian Chai, Ming Niu, Jia Xin Yang
In deregulated electricity markets, predicting price and load is a common practice. However, market participants and shareholders often seek deeper insights into other system statuses associated with price prediction, such as power flow and market share of generation companies (GenCos). These insights are challenging to obtain using purely data-driven methods. This paper proposes a physics-based solution for the probabilistic prediction of market-clearing outcomes, using real sanitized offer data from the National Electricity Market of Singapore (NEMS). Our approach begins with approximating the generator offers that have been historically cleared. Using this pool of offer data, we propose a probabilistic market-clearing process. This process allows for the probabilistic prediction of market prices. By considering the power system network and its constraints, we also naturally obtain probabilistic predictions of power flow and market shares. We validate our approach using actual NEMS data. Our findings show that while the overall performance of price prediction is comparable to existing methods, our proposed method can also provide probabilistic predictions of other associated system operating conditions. Furthermore, our method enables scenario studies, such as the impact of demand-side participation and the penetration of rooftop photovoltaic (PV) systems on the Uniform Singapore Energy Price (USEP).
{"title":"Leveraging sanitized data for probabilistic electricity market prediction: a Singapore case study","authors":"Ning Zhou Xu, Xiang Gao, Songjian Chai, Ming Niu, Jia Xin Yang","doi":"10.3389/fenrg.2023.1296957","DOIUrl":"https://doi.org/10.3389/fenrg.2023.1296957","url":null,"abstract":"In deregulated electricity markets, predicting price and load is a common practice. However, market participants and shareholders often seek deeper insights into other system statuses associated with price prediction, such as power flow and market share of generation companies (GenCos). These insights are challenging to obtain using purely data-driven methods. This paper proposes a physics-based solution for the probabilistic prediction of market-clearing outcomes, using real sanitized offer data from the National Electricity Market of Singapore (NEMS). Our approach begins with approximating the generator offers that have been historically cleared. Using this pool of offer data, we propose a probabilistic market-clearing process. This process allows for the probabilistic prediction of market prices. By considering the power system network and its constraints, we also naturally obtain probabilistic predictions of power flow and market shares. We validate our approach using actual NEMS data. Our findings show that while the overall performance of price prediction is comparable to existing methods, our proposed method can also provide probabilistic predictions of other associated system operating conditions. Furthermore, our method enables scenario studies, such as the impact of demand-side participation and the penetration of rooftop photovoltaic (PV) systems on the Uniform Singapore Energy Price (USEP).","PeriodicalId":503838,"journal":{"name":"Frontiers in Energy Research","volume":"79 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139275318","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 : 2023-11-15DOI: 10.3389/fenrg.2023.1293267
Lyu-Guang Hua, Ammar Ali, S. Ullah, Ghulam Hafeez, Monji Mohamed Zaidi, Liu Jun Jun
This paper introduces a novel control strategy called Finite-time Integral Terminal Sliding Mode Control (FITSMC), explicitly designed for a permanent-magnet synchronous generator (PMSG)-based standalone Wind Energy Conversion System (WECS). The primary objective of the FITSMC strategy is to regulate the operation of the wind turbine efficiently and maximize power extraction from the WECS. To achieve this, the system is driven onto a sliding surface within a predefined terminal time, ensuring rapid convergence and overall stability. An important advantage of the FITSMC strategy is its ability to maintain a standalone wind power system close to the maximum power point, even under varying wind conditions and load changes. In addition, the controller demonstrates robustness against uncertainties and disturbances, making it highly suitable for real-world applications. Extensive simulations and analyses have been conducted to validate the effectiveness of the proposed FITSMC. The results show a superior control performance compared to traditional methods. Consequently, the FITSMC strategy represents a promising advancement in control techniques for standalone wind power systems, providing an efficient and reliable approach for harnessing power from wind energy.
{"title":"Robust finite-time integral terminal sliding mode control design for maximum power extraction of PMSG-based standalone wind energy system","authors":"Lyu-Guang Hua, Ammar Ali, S. Ullah, Ghulam Hafeez, Monji Mohamed Zaidi, Liu Jun Jun","doi":"10.3389/fenrg.2023.1293267","DOIUrl":"https://doi.org/10.3389/fenrg.2023.1293267","url":null,"abstract":"This paper introduces a novel control strategy called Finite-time Integral Terminal Sliding Mode Control (FITSMC), explicitly designed for a permanent-magnet synchronous generator (PMSG)-based standalone Wind Energy Conversion System (WECS). The primary objective of the FITSMC strategy is to regulate the operation of the wind turbine efficiently and maximize power extraction from the WECS. To achieve this, the system is driven onto a sliding surface within a predefined terminal time, ensuring rapid convergence and overall stability. An important advantage of the FITSMC strategy is its ability to maintain a standalone wind power system close to the maximum power point, even under varying wind conditions and load changes. In addition, the controller demonstrates robustness against uncertainties and disturbances, making it highly suitable for real-world applications. Extensive simulations and analyses have been conducted to validate the effectiveness of the proposed FITSMC. The results show a superior control performance compared to traditional methods. Consequently, the FITSMC strategy represents a promising advancement in control techniques for standalone wind power systems, providing an efficient and reliable approach for harnessing power from wind energy.","PeriodicalId":503838,"journal":{"name":"Frontiers in Energy Research","volume":"26 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139272962","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 : 2023-11-15DOI: 10.3389/fenrg.2023.1308750
Yushuo Chen, L. Qu, Zhanqing Yu, Biao Zhao, Qian Kang, Kangsheng Cui, Rong Zeng
High-voltage cascaded energy storage systems have become a major technical direction for the development of large-scale energy storage systems due to the advantages of large unit capacity, high overall efficiency, satisfactory economy, reliable safety, and easy access to grid dispatching. The loss characteristics analysis is the design basis of the water-cooling system of a high-voltage cascaded energy storage system, and its accurate calculation can determine the system’s safe and reliable operation of the system. This paper first introduces the four-quadrant operation principles of a cascaded H-bridge energy storage system, and analyzes the calculation method of the loss of the Integrated Gate-Commutated Thyristor based power module; On this basis, it studies the loss characteristics of the cascaded energy storage system and analyzes the influence of different modulation strategies and third harmonic injection on the loss characteristics of the energy storage system; Finally, this paper has completed the loss test for the engineering prototype module and compared the test results with theoretical calculation results to verify the accuracy of the loss calculation method of the high-voltage cascaded energy storage system.
高压梯级储能系统具有单机容量大、综合效率高、经济性理想、安全可靠、便于接入电网调度等优点，已成为大规模储能系统发展的主要技术方向。损耗特性分析是高压级联储能系统水冷系统的设计基础，其准确计算可决定系统的安全可靠运行。本文首先介绍了级联 H 桥储能系统的四象限工作原理，分析了基于集成门控晶闸管功率模块的损耗计算方法；在此基础上，研究了级联储能系统的损耗特性，分析了不同调制策略和三次谐波注入对储能系统损耗特性的影响；最后，本文完成了工程样机模块的损耗测试，并将测试结果与理论计算结果进行了对比，验证了高压级联储能系统损耗计算方法的准确性。
{"title":"Research on the loss characteristics of high-voltage cascaded energy storage systems based on IGCTs","authors":"Yushuo Chen, L. Qu, Zhanqing Yu, Biao Zhao, Qian Kang, Kangsheng Cui, Rong Zeng","doi":"10.3389/fenrg.2023.1308750","DOIUrl":"https://doi.org/10.3389/fenrg.2023.1308750","url":null,"abstract":"High-voltage cascaded energy storage systems have become a major technical direction for the development of large-scale energy storage systems due to the advantages of large unit capacity, high overall efficiency, satisfactory economy, reliable safety, and easy access to grid dispatching. The loss characteristics analysis is the design basis of the water-cooling system of a high-voltage cascaded energy storage system, and its accurate calculation can determine the system’s safe and reliable operation of the system. This paper first introduces the four-quadrant operation principles of a cascaded H-bridge energy storage system, and analyzes the calculation method of the loss of the Integrated Gate-Commutated Thyristor based power module; On this basis, it studies the loss characteristics of the cascaded energy storage system and analyzes the influence of different modulation strategies and third harmonic injection on the loss characteristics of the energy storage system; Finally, this paper has completed the loss test for the engineering prototype module and compared the test results with theoretical calculation results to verify the accuracy of the loss calculation method of the high-voltage cascaded energy storage system.","PeriodicalId":503838,"journal":{"name":"Frontiers in Energy Research","volume":"522 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139271577","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 : 2023-11-15DOI: 10.3389/fenrg.2023.1302869
Jie Zhang, Chao Tang, Chun Liu, Hai Wang, Junfeng Duan, Sihao Tang
Introduction: Phasor measurement is crucial for the monitoring and management of power grids. Traditional hardware-based phasor measurement units (PMUs) are effective but often complex and expensive. This paper introduces a software-based phasor measurement method that utilizes soft synchronization with temporal pulse signals from GPS and mobile communication stations, offering a simpler and cost-effective alternative.Methods: The proposed method synchronizes the local oscillator with Pulse Per Second (PPS) signals from GPS and primary synchronization signals from mobile communication bases. Raw data affected by the local oscillator’s instability are transformed into calibrated data using B-Spline interpolation to emulate an ideal sampling rate. The calibrated data are then subjected to a Recursive Discrete Fourier Transform (RDFT) algorithm for synchronized phasor measurement.Results: The method’s performance was assessed in compliance with the C37.118.1 standard. Key performance indicators, such as frequency, phase, and Total Vector Error (TVE), were evaluated. The proposed software-based approach demonstrated high accuracy in synchronized phasor measurements.Discussion: The results confirm that the proposed method can serve as a highly accurate and simpler alternative to conventional hardware-based solutions. Its application promises to advance synchronized phasor measurement practices in power grid monitoring, enhancing reliability and reducing complexity and costs.
简介相位测量对于电网的监控和管理至关重要。传统的基于硬件的相位测量单元（PMU）虽然有效，但往往复杂而昂贵。本文介绍了一种基于软件的相位测量方法，它利用 GPS 和移动通信站的时间脉冲信号进行软同步，提供了一种更简单、更经济的替代方法：方法：所提出的方法将本地振荡器与全球定位系统的每秒脉冲（PPS）信号和移动通信基地的主同步信号同步。受本地振荡器不稳定性影响的原始数据通过 B 样条插值法转换为校准数据，以模拟理想的采样率。校准后的数据采用递归离散傅里叶变换（RDFT）算法进行同步相位测量：结果：根据 C37.118.1 标准对该方法的性能进行了评估。对频率、相位和总矢量误差 (TVE) 等关键性能指标进行了评估。所提出的基于软件的方法在同步相位测量中表现出很高的准确性：讨论：结果证实，所提出的方法可作为传统硬件解决方案的高精度和更简单的替代方案。它的应用有望推动电网监测中的同步相位测量实践，提高可靠性并降低复杂性和成本。
{"title":"Phasor measurement method based on soft synchronized sampling with temporal pulse signal reference","authors":"Jie Zhang, Chao Tang, Chun Liu, Hai Wang, Junfeng Duan, Sihao Tang","doi":"10.3389/fenrg.2023.1302869","DOIUrl":"https://doi.org/10.3389/fenrg.2023.1302869","url":null,"abstract":"Introduction: Phasor measurement is crucial for the monitoring and management of power grids. Traditional hardware-based phasor measurement units (PMUs) are effective but often complex and expensive. This paper introduces a software-based phasor measurement method that utilizes soft synchronization with temporal pulse signals from GPS and mobile communication stations, offering a simpler and cost-effective alternative.Methods: The proposed method synchronizes the local oscillator with Pulse Per Second (PPS) signals from GPS and primary synchronization signals from mobile communication bases. Raw data affected by the local oscillator’s instability are transformed into calibrated data using B-Spline interpolation to emulate an ideal sampling rate. The calibrated data are then subjected to a Recursive Discrete Fourier Transform (RDFT) algorithm for synchronized phasor measurement.Results: The method’s performance was assessed in compliance with the C37.118.1 standard. Key performance indicators, such as frequency, phase, and Total Vector Error (TVE), were evaluated. The proposed software-based approach demonstrated high accuracy in synchronized phasor measurements.Discussion: The results confirm that the proposed method can serve as a highly accurate and simpler alternative to conventional hardware-based solutions. Its application promises to advance synchronized phasor measurement practices in power grid monitoring, enhancing reliability and reducing complexity and costs.","PeriodicalId":503838,"journal":{"name":"Frontiers in Energy Research","volume":"35 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139271857","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 : 2023-11-15DOI: 10.3389/fenrg.2023.1240553
Zhanhong Wei, Xu-wang Sun, Wei Chen, Jinhui Shi
The large-scale integration of wind power into the power grid can cause a new type of sub-synchronous power oscillation, different from traditional thermal power generation. The oscillation energy will spread extensively in the grid, causing power oscillation and even grid-cascading events. To address this issue, this article proposes a method for quantitatively analyzing the propagation characteristics of oscillation energy based on branch oscillation energy. Firstly, analyzing the oscillation energy shared by different branches in the network based on transient energy function. Next, a method is proposed to identify the dominant propagation path of sub-synchronous oscillation by defining the oscillation energy of branches under the dominant oscillation mode and the oscillation energy distribution coefficient of each branch. The oscillation partition set formed by the dominant propagation path can be used to locate the high-risk oscillation area of the system. Finally, the effectiveness of the method proposed in this paper for studying the wide-area propagation characteristics of sub-synchronous oscillations was verified through time-domain simulation analysis.
{"title":"Identification of dominant propagation paths based on sub-synchronous oscillation using branch oscillation energy distribution coefficient","authors":"Zhanhong Wei, Xu-wang Sun, Wei Chen, Jinhui Shi","doi":"10.3389/fenrg.2023.1240553","DOIUrl":"https://doi.org/10.3389/fenrg.2023.1240553","url":null,"abstract":"The large-scale integration of wind power into the power grid can cause a new type of sub-synchronous power oscillation, different from traditional thermal power generation. The oscillation energy will spread extensively in the grid, causing power oscillation and even grid-cascading events. To address this issue, this article proposes a method for quantitatively analyzing the propagation characteristics of oscillation energy based on branch oscillation energy. Firstly, analyzing the oscillation energy shared by different branches in the network based on transient energy function. Next, a method is proposed to identify the dominant propagation path of sub-synchronous oscillation by defining the oscillation energy of branches under the dominant oscillation mode and the oscillation energy distribution coefficient of each branch. The oscillation partition set formed by the dominant propagation path can be used to locate the high-risk oscillation area of the system. Finally, the effectiveness of the method proposed in this paper for studying the wide-area propagation characteristics of sub-synchronous oscillations was verified through time-domain simulation analysis.","PeriodicalId":503838,"journal":{"name":"Frontiers in Energy Research","volume":"12 10","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139272207","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 : 2023-11-15DOI: 10.3389/fenrg.2023.1297866
Libiao Zhang, Wuhui Jing, Qilong Wang, Jianing Zhang, Peifang Yang
In order to meet the space heating requirement of residential buildings in low-temperature areas, the performance of the enhanced vapor injection (EVI) air source heat pump (ASHP) system and single-stage compression heat pump system (BASE) using low global warming potential (GWP) working fluids in low-temperature environment are studied. The thermodynamic and emission characteristic models of air source heat pump are developed and optimized, and further compared with traditional heating solutions when used in five different typical cities throughout the world. The results indicate among the selected working fluids, R152a achieves the highest COP of 3.91 among all of the selected low GWP working fluids. When the ambient temperature is 0°C, the maximum COP of the EVI system is 2.51 when CO2 is adopted, and the corresponding optimal discharge pressure and intermediate pressure are 10.57 MPa and 3.83 MPa, respectively. By exploring the changes of HSPF in five typical cities, the HSPF of the EVI system using CO2 is the most significant, which is 17.13%–26.69% higher than the BASE system. The most significant reduction of LCCP in EVI system using CO2 is 15.34%–26.66% compared with BASE system. For SO2 and NOX, the EVI system using R152a has a better emission reduction effect, which is 3.73%–64.73% and 3.72%–66.04% lower than the other solutions, respectively. This study can provide a theoretical reference for the application of low GWP heat pumps with EVI technology.
为了满足低温地区住宅建筑的空间供暖要求，研究了在低温环境下使用低全球升温潜能值（GWP）工作流体的增强型喷气增焓（EVI）空气源热泵（ASHP）系统和单级压缩热泵系统（BASE）的性能。建立并优化了空气源热泵的热力学和排放特性模型，并在全球五个不同的典型城市中与传统供热解决方案进行了进一步比较。结果表明，在所有选定的低全球升温潜能值工作流体中，R152a 的 COP 最高，达到 3.91。当环境温度为 0°C 时，采用 CO2 时，EVI 系统的最大 COP 为 2.51，相应的最佳排放压力和中间压力分别为 10.57 MPa 和 3.83 MPa。通过探究五个典型城市的 HSPF 变化，采用 CO2 的 EVI 系统的 HSPF 最大，比 BASE 系统高 17.13%-26.69%。与 BASE 系统相比，使用 CO2 的 EVI 系统的 LCCP 降低幅度最大，为 15.34%-26.66%。对于二氧化硫和氮氧化物，使用 R152a 的 EVI 系统具有更好的减排效果，分别比其他方案低 3.73%-64.73% 和 3.72%-66.04% 。该研究可为采用 EVI 技术的低 GWP 热泵的应用提供理论参考。
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Pub Date : 2023-11-14DOI: 10.3389/fenrg.2023.1333023
Shuyang Liu, Hangyu Li, Yi Zhang, Bo Ren, Qian Sun
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