The fluctuation and stochastic characteristics of renewable energy resources challenge the secure system operation and also impose significant financial risks for the market participating renewable energy plants (REPs). Energy storage systems (ESSs) can serve as effective tools in enhancing the operating flexibility of REPs, thus improving their profitability while making them grid-friendly. However, current studies focussing on the energy market participation of ESS-equipped REPs neglect ESSs' frequency regulation performance. Moreover, power output deviation and power curtailment of REPs bring difficulties to the integration of renewable energy. To address these challenges, an optimal ESS configuration method for REPs participating in the joint energy-regulation market is proposed first. A method considering constraints on frequency regulation performance is applied. Then, to reduce power output deviation and power curtailment of REPs, an incentive mechanism based on the excess revenue recovery is implemented to induce the grid-friendly power outputs of REPs. Numerical analysis on XJTU-ROTS2017 systems demonstrates that the optimal ESS configuration results obtained from the proposed method could promote the profitability of ESS-equipped REPs. The results also verify the effectiveness of the excess revenue recovery mechanism in facilitating the grid-friendly operation behaviours of the ESS-equipped REPs.
{"title":"Optimal energy storage configuration for joint energy-regulation market participating renewable energy plants with excess revenue recovery mechanism","authors":"Weihong Liu, Qiangyu Ren, Jiaojiao Deng, Jincheng Guo, Xiaoming Zheng, Hongli Liu","doi":"10.1049/esi2.12112","DOIUrl":"10.1049/esi2.12112","url":null,"abstract":"<p>The fluctuation and stochastic characteristics of renewable energy resources challenge the secure system operation and also impose significant financial risks for the market participating renewable energy plants (REPs). Energy storage systems (ESSs) can serve as effective tools in enhancing the operating flexibility of REPs, thus improving their profitability while making them grid-friendly. However, current studies focussing on the energy market participation of ESS-equipped REPs neglect ESSs' frequency regulation performance. Moreover, power output deviation and power curtailment of REPs bring difficulties to the integration of renewable energy. To address these challenges, an optimal ESS configuration method for REPs participating in the joint energy-regulation market is proposed first. A method considering constraints on frequency regulation performance is applied. Then, to reduce power output deviation and power curtailment of REPs, an incentive mechanism based on the excess revenue recovery is implemented to induce the grid-friendly power outputs of REPs. Numerical analysis on XJTU-ROTS2017 systems demonstrates that the optimal ESS configuration results obtained from the proposed method could promote the profitability of ESS-equipped REPs. The results also verify the effectiveness of the excess revenue recovery mechanism in facilitating the grid-friendly operation behaviours of the ESS-equipped REPs.</p>","PeriodicalId":33288,"journal":{"name":"IET Energy Systems Integration","volume":"5 4","pages":"418-429"},"PeriodicalIF":2.4,"publicationDate":"2023-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ietresearch.onlinelibrary.wiley.com/doi/epdf/10.1049/esi2.12112","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46328329","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}
The DC-side stability of the grid-tied converter under different control modes is fully investigated using electrical torque analysis. The small-signal model of a single converter connected to an ideal DC bus under various control modes is formulated. Accordingly, the damping and synchronising coefficient contributed by the DC network and controllers of grid-tied converter are separately accessed using the electrical torque analysis method and the stabilising conditions of the grid-tied converter operating under different control modes are further derived. The system stability mainly corresponds with DC network dynamics under constant active power control mode. On the contrary, the grid-tied converter under constant DC-link voltage control mode has no stability problem. Generally, elevating the DC-link capacitance or decreasing the droop gain can greatly improve the stability margin reserve of the VSC-HVDC links. In addition, the control gains of the classical PQ controller are proven to have limited impacts on DC-side system stability. Finally, the results of numerical simulation prove the validity of the proposed stability analysis method and the stable boundary for the grid-tied converter with different control modes.
{"title":"DC-side stability analysis of grid-tied converter with different control modes based on electrical torque analysis","authors":"Xu Zhang, Yujun Li, Jiapeng Li, Ting Wu, Songhao Yang, Zhiguo Hao","doi":"10.1049/esi2.12110","DOIUrl":"10.1049/esi2.12110","url":null,"abstract":"<p>The DC-side stability of the grid-tied converter under different control modes is fully investigated using electrical torque analysis. The small-signal model of a single converter connected to an ideal DC bus under various control modes is formulated. Accordingly, the damping and synchronising coefficient contributed by the DC network and controllers of grid-tied converter are separately accessed using the electrical torque analysis method and the stabilising conditions of the grid-tied converter operating under different control modes are further derived. The system stability mainly corresponds with DC network dynamics under constant active power control mode. On the contrary, the grid-tied converter under constant DC-link voltage control mode has no stability problem. Generally, elevating the DC-link capacitance or decreasing the droop gain can greatly improve the stability margin reserve of the VSC-HVDC links. In addition, the control gains of the classical PQ controller are proven to have limited impacts on DC-side system stability. Finally, the results of numerical simulation prove the validity of the proposed stability analysis method and the stable boundary for the grid-tied converter with different control modes.</p>","PeriodicalId":33288,"journal":{"name":"IET Energy Systems Integration","volume":"6 1","pages":"31-44"},"PeriodicalIF":2.4,"publicationDate":"2023-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/esi2.12110","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43967221","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}
The energy storage system (ESS) is a promising technology to address issues caused by the large-scale deployment of renewable energy. Deploying ESS is a business decision that requires potential revenue assessment. Current value assessment methods focus on the energy storage owner or the electricity utility. The system value of the ESS needs to be fully considered to gain a broad understanding of benefits across the whole power system. Thus, this study proposes a system value assessment method of grid-integrated ESS to quantify the total system value-avoided cost based on an improved DC power flow model considering transmission losses. Four typical applications (production cost saving, upgrade deferral, environmental benefit, and transmission loss saving) are chosen to represent the system value of the ESS across the whole power system. In addition, the co-optimisation model considering the “source-grid-storage” coordination operation and battery capacity degradation, is proposed for peak shaving and frequency regulation based on the Chinese power market rule. The proposed method is tested in simulation and experimental studies.
{"title":"System value assessment method of energy storage system for multi-services of power system considering battery degradation","authors":"Yinguo Yang, Yenan Wang, Qiuyu Lu, Guangchun Ruan, Yingming Lin, Xuan Wang, Pingping Xie, Haiwang Zhong","doi":"10.1049/esi2.12109","DOIUrl":"10.1049/esi2.12109","url":null,"abstract":"<p>The energy storage system (ESS) is a promising technology to address issues caused by the large-scale deployment of renewable energy. Deploying ESS is a business decision that requires potential revenue assessment. Current value assessment methods focus on the energy storage owner or the electricity utility. The system value of the ESS needs to be fully considered to gain a broad understanding of benefits across the whole power system. Thus, this study proposes a system value assessment method of grid-integrated ESS to quantify the total system value-avoided cost based on an improved DC power flow model considering transmission losses. Four typical applications (production cost saving, upgrade deferral, environmental benefit, and transmission loss saving) are chosen to represent the system value of the ESS across the whole power system. In addition, the co-optimisation model considering the “source-grid-storage” coordination operation and battery capacity degradation, is proposed for peak shaving and frequency regulation based on the Chinese power market rule. The proposed method is tested in simulation and experimental studies.</p>","PeriodicalId":33288,"journal":{"name":"IET Energy Systems Integration","volume":"5 3","pages":"355-364"},"PeriodicalIF":2.4,"publicationDate":"2023-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/esi2.12109","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44081552","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}
William Seward, Lixun Chi, Meysam Qadrdan, Adib Allahham, Khaled Alawasa
Remote areas in Jordan often rely on expensive and polluting diesel generators to meet their electricity demand. This study investigates 100% renewable solutions to supply the electricity demand of off-grid energy systems through optimal sizing of photovoltaics and energy storage systems. A linear programming approach is proposed to minimise the annualised cost of electricity supply including capital costs of equipment and their operation and maintenance costs. The optimisation determines the size of photovoltaics and energy storage required to satisfy electricity demand at every hour of a selected year. A Jordan campsite was used as a case study to assess and compare the performance of PV-battery storage and PV-hydrogen storage systems from economic and reliability perspectives. The results show that hydrogen storage was more economical for a 100% renewable energy system. However, introducing some diesel generation gave the battery system a significantly lower annualised cost of energy.
{"title":"Sizing, economic, and reliability analysis of photovoltaics and energy storage for an off-grid power system in Jordan","authors":"William Seward, Lixun Chi, Meysam Qadrdan, Adib Allahham, Khaled Alawasa","doi":"10.1049/esi2.12108","DOIUrl":"10.1049/esi2.12108","url":null,"abstract":"<p>Remote areas in Jordan often rely on expensive and polluting diesel generators to meet their electricity demand. This study investigates 100% renewable solutions to supply the electricity demand of off-grid energy systems through optimal sizing of photovoltaics and energy storage systems. A linear programming approach is proposed to minimise the annualised cost of electricity supply including capital costs of equipment and their operation and maintenance costs. The optimisation determines the size of photovoltaics and energy storage required to satisfy electricity demand at every hour of a selected year. A Jordan campsite was used as a case study to assess and compare the performance of PV-battery storage and PV-hydrogen storage systems from economic and reliability perspectives. The results show that hydrogen storage was more economical for a 100% renewable energy system. However, introducing some diesel generation gave the battery system a significantly lower annualised cost of energy.</p>","PeriodicalId":33288,"journal":{"name":"IET Energy Systems Integration","volume":"5 4","pages":"393-404"},"PeriodicalIF":2.4,"publicationDate":"2023-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ietresearch.onlinelibrary.wiley.com/doi/epdf/10.1049/esi2.12108","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46185726","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}
Jin Gao, Zhenguo Shao, Feixiong Chen, Yuchao Chen, Yongqi Lin, Hongjie Deng
In microgrid (MG) systems, traditional centralised energy trading models can lead to issues such as low energy efficiency due to unstable energy supply and lack of flexibility. Peer-to-peer (P2P) trading models have been widely used due to their advantages in promoting the sustainable development of renewable energy and reducing energy trading costs. However, P2P multi-energy trading requires mutual agreements between two microgrids (MGs), and the uncertainties of renewable energy and load affects energy supply security. To address these issues, this article proposed a distributed robust operation strategy based on P2P multi-energy trading for multi-microgrid (MMG) systems. Firstly, a two-stage robust optimisation (TRO) method was adopted to consider the uncertainties of P2P multi-energy trading between MGs, which reduced the conservatism of robust optimisation (RO). Secondly, a TRO model for P2P multi-energy trading among MGs was established based on the Nash bargaining theory, where each MG negotiates with others based on their energy contributions in the cooperation. Additionally, a distributed algorithm was used to protect the privacy of each MG. Finally, the simulation results based on three MGs showed that the proposed approach can achieve a fair distribution of cooperative interests and effectively promote cooperation among MGs.
{"title":"Distributed robust operation strategy of multi-microgrid based on peer-to-peer multi-energy trading","authors":"Jin Gao, Zhenguo Shao, Feixiong Chen, Yuchao Chen, Yongqi Lin, Hongjie Deng","doi":"10.1049/esi2.12107","DOIUrl":"10.1049/esi2.12107","url":null,"abstract":"<p>In microgrid (MG) systems, traditional centralised energy trading models can lead to issues such as low energy efficiency due to unstable energy supply and lack of flexibility. Peer-to-peer (P2P) trading models have been widely used due to their advantages in promoting the sustainable development of renewable energy and reducing energy trading costs. However, P2P multi-energy trading requires mutual agreements between two microgrids (MGs), and the uncertainties of renewable energy and load affects energy supply security. To address these issues, this article proposed a distributed robust operation strategy based on P2P multi-energy trading for multi-microgrid (MMG) systems. Firstly, a two-stage robust optimisation (TRO) method was adopted to consider the uncertainties of P2P multi-energy trading between MGs, which reduced the conservatism of robust optimisation (RO). Secondly, a TRO model for P2P multi-energy trading among MGs was established based on the Nash bargaining theory, where each MG negotiates with others based on their energy contributions in the cooperation. Additionally, a distributed algorithm was used to protect the privacy of each MG. Finally, the simulation results based on three MGs showed that the proposed approach can achieve a fair distribution of cooperative interests and effectively promote cooperation among MGs.</p>","PeriodicalId":33288,"journal":{"name":"IET Energy Systems Integration","volume":"5 4","pages":"376-392"},"PeriodicalIF":2.4,"publicationDate":"2023-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ietresearch.onlinelibrary.wiley.com/doi/epdf/10.1049/esi2.12107","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45696556","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}
The application of the security region methodology in a practical distribution system with large scale normally requires large computer memory and high computation time. To overcome this problem, this article proposes a decoupling and dimension reduction method, which can significantly accelerate the calculation of distribution system security region (DSSR) and is important for the application of the DSSR theory in large-scale distribution systems. First, the definition of DSSR dimension reflecting the size of solution space and the time complexity is proposed. And the solution algorithm for DSSR dimension is also given. Second, a decoupling and dimension reduction method suitable for the analysis of DSSR is proposed. Following the method, an incidence matrix can be obtained from the DSSR expressions, which can be further divided into multiple block matrices. According to the feeder combinations of the block matrices, the distribution system can be decoupled into multiple sub-networks for more efficient analysis. Finally, a 10kV distribution network is used in case study to validate the proposed method. The results for a time-consuming calculation, that is, TSC curve calculation, show that the proposed method can reduce the computation time significantly, making the time-consuming calculation suitable for the analysis of large-scale cases.
{"title":"Decoupling and dimension reduction method for distribution system security region","authors":"Jun Xiao, Yuhao Fan, Xun Jiang","doi":"10.1049/esi2.12105","DOIUrl":"https://doi.org/10.1049/esi2.12105","url":null,"abstract":"<p>The application of the security region methodology in a practical distribution system with large scale normally requires large computer memory and high computation time. To overcome this problem, this article proposes a decoupling and dimension reduction method, which can significantly accelerate the calculation of distribution system security region (DSSR) and is important for the application of the DSSR theory in large-scale distribution systems. First, the definition of DSSR dimension reflecting the size of solution space and the time complexity is proposed. And the solution algorithm for DSSR dimension is also given. Second, a decoupling and dimension reduction method suitable for the analysis of DSSR is proposed. Following the method, an incidence matrix can be obtained from the DSSR expressions, which can be further divided into multiple block matrices. According to the feeder combinations of the block matrices, the distribution system can be decoupled into multiple sub-networks for more efficient analysis. Finally, a 10kV distribution network is used in case study to validate the proposed method. The results for a time-consuming calculation, that is, TSC curve calculation, show that the proposed method can reduce the computation time significantly, making the time-consuming calculation suitable for the analysis of large-scale cases.</p>","PeriodicalId":33288,"journal":{"name":"IET Energy Systems Integration","volume":"5 3","pages":"338-354"},"PeriodicalIF":2.4,"publicationDate":"2023-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/esi2.12105","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50126253","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}
The application of the security region methodology in a practical distribution system with large scale normally requires large computer memory and high computation time. To overcome this problem, this article proposes a decoupling and dimension reduction method, which can significantly accelerate the calculation of distribution system security region (DSSR) and is important for the application of the DSSR theory in large ‐ scale distribution systems. First, the definition of DSSR dimension reflecting the size of so-lution space and the time complexity is proposed. And the solution algorithm for DSSR dimension is also given. Second, a decoupling and dimension reduction method suitable for the analysis of DSSR is proposed. Following the method, an incidence matrix can be obtained from the DSSR expressions, which can be further divided into multiple block matrices. According to the feeder combinations of the block matrices, the distribution system can be decoupled into multiple sub ‐ networks for more efficient analysis. Finally, a 10kV distribution network is used in case study to validate the proposed method. The results for a time ‐ consuming calculation, that is, TSC curve calculation, show that the proposed method can reduce the computation time significantly, making the time ‐ consuming calculation suitable for the analysis of large ‐ scale cases.
{"title":"Decoupling and dimension reduction method for distribution system security region","authors":"Jun Xiao, Yuhao Fan, Xun Jiang","doi":"10.1049/esi2.12105","DOIUrl":"https://doi.org/10.1049/esi2.12105","url":null,"abstract":"The application of the security region methodology in a practical distribution system with large scale normally requires large computer memory and high computation time. To overcome this problem, this article proposes a decoupling and dimension reduction method, which can significantly accelerate the calculation of distribution system security region (DSSR) and is important for the application of the DSSR theory in large ‐ scale distribution systems. First, the definition of DSSR dimension reflecting the size of so-lution space and the time complexity is proposed. And the solution algorithm for DSSR dimension is also given. Second, a decoupling and dimension reduction method suitable for the analysis of DSSR is proposed. Following the method, an incidence matrix can be obtained from the DSSR expressions, which can be further divided into multiple block matrices. According to the feeder combinations of the block matrices, the distribution system can be decoupled into multiple sub ‐ networks for more efficient analysis. Finally, a 10kV distribution network is used in case study to validate the proposed method. The results for a time ‐ consuming calculation, that is, TSC curve calculation, show that the proposed method can reduce the computation time significantly, making the time ‐ consuming calculation suitable for the analysis of large ‐ scale cases.","PeriodicalId":33288,"journal":{"name":"IET Energy Systems Integration","volume":"1 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2023-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57947771","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}
Islanded microgrid network is sensitive to voltage and frequency fluctuations which becomes more vulnerable in the presence of external disturbance and the intermittent nature of Renewable Energy Sources (RESs). The “Electric Spring” (ES) is one of the most effective and efficient solutions for enhancing operational flexibility and RESs integration. A Self-Excited Induction Generator (SEIG) based Micro hydro system with ES, non-critical and critical loads is considered. Both non-critical and critical loads are connected in 2:1 ratio in parallel with SEIG. The concept of voltage-sensitive and non-sensitive loads and the “power demand following the supply” idea have been incorporated for pointing up the contribution of ES. The non-critical load coupled with a three-phase inverter acts like an ES and can be operated as a Smart Load (SL). SL can compensate the voltage deviation between demand-supply side, therefore mitigating the voltage fluctuations. The effectiveness of ES in terms of voltage regulation at the point of standard coupling has been achieved which improved the overall voltage profile of the hybrid microgrid system which can be observed from various test cases. A hardware in loop microgrid experimental platform is established and its results highlight the excellent performance of the proposed method.
{"title":"Real-time voltage control of electric spring in islanded condition","authors":"Deepsikha Panda, Pratim Kundu, Bharat Singh Rajpurohit","doi":"10.1049/esi2.12104","DOIUrl":"10.1049/esi2.12104","url":null,"abstract":"<p>Islanded microgrid network is sensitive to voltage and frequency fluctuations which becomes more vulnerable in the presence of external disturbance and the intermittent nature of Renewable Energy Sources (RESs). The “Electric Spring” (ES) is one of the most effective and efficient solutions for enhancing operational flexibility and RESs integration. A Self-Excited Induction Generator (SEIG) based Micro hydro system with ES, non-critical and critical loads is considered. Both non-critical and critical loads are connected in 2:1 ratio in parallel with SEIG. The concept of voltage-sensitive and non-sensitive loads and the “power demand following the supply” idea have been incorporated for pointing up the contribution of ES. The non-critical load coupled with a three-phase inverter acts like an ES and can be operated as a Smart Load (SL). SL can compensate the voltage deviation between demand-supply side, therefore mitigating the voltage fluctuations. The effectiveness of ES in terms of voltage regulation at the point of standard coupling has been achieved which improved the overall voltage profile of the hybrid microgrid system which can be observed from various test cases. A hardware in loop microgrid experimental platform is established and its results highlight the excellent performance of the proposed method.</p>","PeriodicalId":33288,"journal":{"name":"IET Energy Systems Integration","volume":"5 3","pages":"307-319"},"PeriodicalIF":2.4,"publicationDate":"2023-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/esi2.12104","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49073817","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 trilateral control for LCL filter-based system is introduced by the authors with a single grid current sensor in weak grid conditions. The LCL filter increases the complexity when the uncertain nature of the grid comes into the picture. Moreover, the traditional three-loop control technique requires three current sensors on the inverter side, three voltage sensors to sense voltage across the capacitor, and three current sensors on the grid side combined for sensing. A novel trilateral control technique utilising a single sensor is implemented to sense the grid current. This technique has reduced a considerable number of current sensors and voltage sensors. The α axis of grid current is proportional to sensed ‘a’ phase grid current. The β current in the utility grid is acquired by employing the controller reference quantities of the grid current. The computation of another variable, that is, the current in the inverter side inductor and the voltage across the capacitor, is executed by an estimation algorithm. The proposed technique provides the feature of reducing implementation financial value and weight that reduces the complexity and size of hardware. The synchronisation technique is executed by a modified dual second-order generalised integrator digital phase-locked loop for the grid-connected converter. The implemented system offers the advantage of ease of implementation, good performance, and high stability. The validity of the proposed scheme in the implemented system is demonstrated by the simulated waveform obtained on the MATLAB/Simulink platform. Finally, the effectiveness of the proposed system is further justified by the experimental waveform procured from a prototype developed in the laboratory.
作者介绍了一种基于 LCL 滤波器的三边控制系统,在弱电网条件下使用单个电网电流传感器。当电网出现不确定性时,LCL 滤波器会增加复杂性。此外,传统的三环控制技术需要在逆变器侧安装三个电流传感器、三个电压传感器来检测电容器上的电压,以及在电网侧安装三个电流传感器来进行检测。新颖的三边控制技术利用单个传感器来感应电网电流。该技术减少了大量电流传感器和电压传感器。电网电流的 α 轴与感应到的 "a "相电网电流成正比。公用电网中的β电流是通过使用电网电流的控制器参考量获得的。另一个变量,即逆变器侧电感器中的电流和电容器上的电压,则通过估算算法进行计算。所提出的技术具有降低实施财务价值和重量的特点,从而减少了硬件的复杂性和大小。同步技术由并网转换器的改进型双二阶广义积分器数字锁相环执行。所实现的系统具有易于实施、性能良好和稳定性高等优点。在 MATLAB/Simulink 平台上获得的仿真波形证明了所提方案在所实施系统中的有效性。最后,从实验室开发的原型获得的实验波形进一步证明了所提系统的有效性。
{"title":"Trilateral control for LCL filter-based system with single grid current sensor in weak grid","authors":"Khushboo Kumari, Amit Kumar Jain","doi":"10.1049/esi2.12106","DOIUrl":"10.1049/esi2.12106","url":null,"abstract":"<p>A trilateral control for <i>LCL</i> filter-based system is introduced by the authors with a single grid current sensor in weak grid conditions. The <i>LCL</i> filter increases the complexity when the uncertain nature of the grid comes into the picture. Moreover, the traditional three-loop control technique requires three current sensors on the inverter side, three voltage sensors to sense voltage across the capacitor, and three current sensors on the grid side combined for sensing. A novel trilateral control technique utilising a single sensor is implemented to sense the grid current. This technique has reduced a considerable number of current sensors and voltage sensors. The <i>α</i> axis of grid current is proportional to sensed ‘a’ phase grid current. The <i>β</i> current in the utility grid is acquired by employing the controller reference quantities of the grid current. The computation of another variable, that is, the current in the inverter side inductor and the voltage across the capacitor, is executed by an estimation algorithm. The proposed technique provides the feature of reducing implementation financial value and weight that reduces the complexity and size of hardware. The synchronisation technique is executed by a modified dual second-order generalised integrator digital phase-locked loop for the grid-connected converter. The implemented system offers the advantage of ease of implementation, good performance, and high stability. The validity of the proposed scheme in the implemented system is demonstrated by the simulated waveform obtained on the MATLAB/Simulink platform. Finally, the effectiveness of the proposed system is further justified by the experimental waveform procured from a prototype developed in the laboratory.</p>","PeriodicalId":33288,"journal":{"name":"IET Energy Systems Integration","volume":"5 4","pages":"365-375"},"PeriodicalIF":2.4,"publicationDate":"2023-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ietresearch.onlinelibrary.wiley.com/doi/epdf/10.1049/esi2.12106","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44051995","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}
Mixed integer linear programming (MILP)–based distributed energy management for networked microgrids embedded modern distribution systems is proposed. Considering the diverse ownership of microgrids, distributed energy resources (DERs) that interface directly with utilities and responsive loads, an alternating direction method of multipliers–based distributed framework was formulated for the scheduling of networked microgrids embedded modern distribution systems by adjusting nodal price signals iteratively. In addition, to make the formulated optimization problems resolvable through more accessible and popular MILP solvers, different linearisation techniques were employed to transform the nonlinear terms into linear or mixed integer linear formats. The proposed MILP-based distributed method preserves all participants' autonomy (e.g., microgrids, DERs that interface directly with utilities and responsive loads), while incentivising them to actively participate in the distribution system operation with price signals. The proposed method is validated with results of numerical simulation using a modern distribution system consisting of multiple networked microgrids, DERs that interface directly with utilities, as well as responsive loads.
{"title":"A Mixed integer linear programming-based distributed energy management for networked microgrids considering network operational objectives and constraints","authors":"Guodong Liu, Maximiliano F. Ferrari, Yang Chen","doi":"10.1049/esi2.12103","DOIUrl":"10.1049/esi2.12103","url":null,"abstract":"<p>Mixed integer linear programming (MILP)–based distributed energy management for networked microgrids embedded modern distribution systems is proposed. Considering the diverse ownership of microgrids, distributed energy resources (DERs) that interface directly with utilities and responsive loads, an alternating direction method of multipliers–based distributed framework was formulated for the scheduling of networked microgrids embedded modern distribution systems by adjusting nodal price signals iteratively. In addition, to make the formulated optimization problems resolvable through more accessible and popular MILP solvers, different linearisation techniques were employed to transform the nonlinear terms into linear or mixed integer linear formats. The proposed MILP-based distributed method preserves all participants' autonomy (e.g., microgrids, DERs that interface directly with utilities and responsive loads), while incentivising them to actively participate in the distribution system operation with price signals. The proposed method is validated with results of numerical simulation using a modern distribution system consisting of multiple networked microgrids, DERs that interface directly with utilities, as well as responsive loads.</p>","PeriodicalId":33288,"journal":{"name":"IET Energy Systems Integration","volume":"5 3","pages":"320-337"},"PeriodicalIF":2.4,"publicationDate":"2023-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/esi2.12103","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43001627","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}