Pub Date : 2025-02-06DOI: 10.1109/TPWRD.2025.3539280
Chenhao Zhang;Yan Jifei;Guobing Song
Zone III distance protection has long operating time and its sensitivity decreases significantly in renewable energy scenarios. In this paper, novel single-ended remote backup protection is proposed based on fault location information contained in traveling wavefront. Firstly, it is demonstrated that the fault distance factor of traveling wavefront is effective in reflecting location of fault in both radial and meshed topologies. Then fault distance-operating time inverse-time characteristic is designed based on fault distance factor, realizing spontaneous sequencing of operating time between the relays at higher and lower zones. This inverse-time characteristic is only determined by location of fault and not influenced by operation mode, control strategy, fault type, fault resistance, etc. A robust algorithm is proposed to efficiently extract the fault distance factor, ensuring protection reliability. Resetting criterions are designed to re-check the existence of fault, avoiding leapfrog tripping and maloperation confronting disturbances. The setting of proposed protection is simple, without the need to update the threshold value according to the system status. Verifications have demonstrated that the proposed protection can be self-adaptive to flexible operation mode of renewable energy transmission system and different topologies. The proposed method also demonstrates high tolerance to fault resistance and noise while maintaining fast operating speed.
{"title":"Single-Ended Remote Backup Protection Based on Fault Distance Factor of Traveling Wavefront","authors":"Chenhao Zhang;Yan Jifei;Guobing Song","doi":"10.1109/TPWRD.2025.3539280","DOIUrl":"10.1109/TPWRD.2025.3539280","url":null,"abstract":"Zone III distance protection has long operating time and its sensitivity decreases significantly in renewable energy scenarios. In this paper, novel single-ended remote backup protection is proposed based on fault location information contained in traveling wavefront. Firstly, it is demonstrated that the fault distance factor of traveling wavefront is effective in reflecting location of fault in both radial and meshed topologies. Then fault distance-operating time inverse-time characteristic is designed based on fault distance factor, realizing spontaneous sequencing of operating time between the relays at higher and lower zones. This inverse-time characteristic is only determined by location of fault and not influenced by operation mode, control strategy, fault type, fault resistance, etc. A robust algorithm is proposed to efficiently extract the fault distance factor, ensuring protection reliability. Resetting criterions are designed to re-check the existence of fault, avoiding leapfrog tripping and maloperation confronting disturbances. The setting of proposed protection is simple, without the need to update the threshold value according to the system status. Verifications have demonstrated that the proposed protection can be self-adaptive to flexible operation mode of renewable energy transmission system and different topologies. The proposed method also demonstrates high tolerance to fault resistance and noise while maintaining fast operating speed.","PeriodicalId":13498,"journal":{"name":"IEEE Transactions on Power Delivery","volume":"40 2","pages":"1143-1157"},"PeriodicalIF":3.8,"publicationDate":"2025-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143258522","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-06DOI: 10.1109/TPWRD.2025.3539334
Mingwang Xu;Wei Gu;Yang Cao;Shuaixian Chen;Fei Zhang;Wei Liu
Currently, a multitude of power electronic devices are connected to the grid, and the safe and stable operation of the grid depends on the analysis of electromagnetic transient (EMT) simulation technology. This paper proposes a state variables elimination-based EMTP-type constant admittance equivalent modeling method for power electronic converters. The method employs a three-layer architecture consisting of ‘network-nodal voltages-historical current source’. The low-order equivalent nodal voltage equation is generated by using matrix splitting and adding output equations. The proposed method is distinguished by a constant admittance matrix and the consideration of internal characteristics, which facilitates straightforward access to external circuit, low time-complexity, and uncomplicated modeling procedures in comparison with the classical node elimination method (NEM). Furthermore, it exhibits a degree of generality regarding modular and unitized electrical equipment. The accuracy of the proposed method is validated by comparison with the off-line EMT simulation and experiments. The test results demonstrate that the proposed method exhibits high accuracy and efficiency in a variety of scenarios.
{"title":"A State Variables Elimination-Based EMTP-Type Constant Admittance Equivalent Modeling Method for Power Electronic Converters","authors":"Mingwang Xu;Wei Gu;Yang Cao;Shuaixian Chen;Fei Zhang;Wei Liu","doi":"10.1109/TPWRD.2025.3539334","DOIUrl":"10.1109/TPWRD.2025.3539334","url":null,"abstract":"Currently, a multitude of power electronic devices are connected to the grid, and the safe and stable operation of the grid depends on the analysis of electromagnetic transient (EMT) simulation technology. This paper proposes a state variables elimination-based EMTP-type constant admittance equivalent modeling method for power electronic converters. The method employs a three-layer architecture consisting of ‘network-nodal voltages-historical current source’. The low-order equivalent nodal voltage equation is generated by using matrix splitting and adding output equations. The proposed method is distinguished by a constant admittance matrix and the consideration of internal characteristics, which facilitates straightforward access to external circuit, low time-complexity, and uncomplicated modeling procedures in comparison with the classical node elimination method (NEM). Furthermore, it exhibits a degree of generality regarding modular and unitized electrical equipment. The accuracy of the proposed method is validated by comparison with the off-line EMT simulation and experiments. The test results demonstrate that the proposed method exhibits high accuracy and efficiency in a variety of scenarios.","PeriodicalId":13498,"journal":{"name":"IEEE Transactions on Power Delivery","volume":"40 2","pages":"1100-1113"},"PeriodicalIF":3.8,"publicationDate":"2025-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143258568","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-05DOI: 10.1109/TPWRD.2025.3538914
Zheren Zhang;Hanlin Guo;Zheng Xu
A fast increasing proportion of renewable energy is the main development trend in today's power systems. The modular multilevel converter (MMC) station adaptable for both strong and weak grids is a potential solution when connecting to AC grids with a high proportion of power electronics. In this paper, a synchronous machine imitation control scheme of the MMC stations is proposed. The proposed control scheme consists of the basic control for normal operation and the additional control for AC fault riding through. With the basic control, the MMC station behaves as a synchronous machine. Then, based on small disturbance stability analysis, the low frequency damping characteristics are analyzed, demonstrating the proposed control's adaptability to both strong and weak grids under small disturbance. For the additional control, its performance under large disturbance is studied by time domain simulation. The time domain simulations are carried out in PSCAD/EMTDC for both the weak and strong grids, and the feasibility of the additional control under AC fault is also verified.
{"title":"Synchronous Machine Imitation Control of MMC Stations Adaptable for Both Strong and Weak Grids","authors":"Zheren Zhang;Hanlin Guo;Zheng Xu","doi":"10.1109/TPWRD.2025.3538914","DOIUrl":"10.1109/TPWRD.2025.3538914","url":null,"abstract":"A fast increasing proportion of renewable energy is the main development trend in today's power systems. The modular multilevel converter (MMC) station adaptable for both strong and weak grids is a potential solution when connecting to AC grids with a high proportion of power electronics. In this paper, a synchronous machine imitation control scheme of the MMC stations is proposed. The proposed control scheme consists of the basic control for normal operation and the additional control for AC fault riding through. With the basic control, the MMC station behaves as a synchronous machine. Then, based on small disturbance stability analysis, the low frequency damping characteristics are analyzed, demonstrating the proposed control's adaptability to both strong and weak grids under small disturbance. For the additional control, its performance under large disturbance is studied by time domain simulation. The time domain simulations are carried out in PSCAD/EMTDC for both the weak and strong grids, and the feasibility of the additional control under AC fault is also verified.","PeriodicalId":13498,"journal":{"name":"IEEE Transactions on Power Delivery","volume":"40 2","pages":"912-926"},"PeriodicalIF":3.8,"publicationDate":"2025-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143191957","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Traveling wave differential protection (TWDP) is based on the traveling wave (TW) propagation characteristics of the physical transmission line and therefore holds unique advantages in the protection of long-distance transmission lines. This paper proposes a practical time-domain TWDP scheme specifically designed for high-voltage direct-current (HVDC) lines and provides both theoretical analysis and field validation. A TWDP device, named TP-03, was developed and underwent laboratory testing. The developed protection device 1) can stay valid under a maximum fault impedance of up to 1000 $Omega$ under the rated $pm$ 1100 kV voltage level; 2) has an operation time of less than 30 ms even with a communication delay of 20 ms. In October 2020, TP-03 devices were first deployed on the Changji-Guquan UHVDC transmission project, which is the highest voltage ($pm$ 1100 kV), longest distance (3284 km), and largest capacity (rated 12100 MW) transmission project in the world. During its operation, the devices functioned correctly in several internal faults and external disturbance events. This work represents the first field validation of HVDC TWDP and bridges the gap between theoretical research and real-world applications. It confirms that TWDP can serve as the main protection for ultra-long-distance HVDC lines, setting a benchmark for future projects.
{"title":"Traveling Wave Differential Protection Technology and Its Application in Ultra-Long-Distance UHVDC Transmission Line","authors":"Xinzhou Dong;Haozong Wang;Binshu Chen;Boliang Jin;Xinyuan Li;Qihuan Dong;Shenxing Shi;Bin Wang;Pengfei Lv;Guoming Qian;Fufeng Chen;Zhanfeng Fan;Baowei Li;Min Xie;Xiaoping Feng","doi":"10.1109/TPWRD.2025.3536181","DOIUrl":"10.1109/TPWRD.2025.3536181","url":null,"abstract":"Traveling wave differential protection (TWDP) is based on the traveling wave (TW) propagation characteristics of the physical transmission line and therefore holds unique advantages in the protection of long-distance transmission lines. This paper proposes a practical time-domain TWDP scheme specifically designed for high-voltage direct-current (HVDC) lines and provides both theoretical analysis and field validation. A TWDP device, named TP-03, was developed and underwent laboratory testing. The developed protection device 1) can stay valid under a maximum fault impedance of up to 1000 <inline-formula><tex-math>$Omega$</tex-math></inline-formula> under the rated <inline-formula><tex-math>$pm$</tex-math></inline-formula> 1100 kV voltage level; 2) has an operation time of less than 30 ms even with a communication delay of 20 ms. In October 2020, TP-03 devices were first deployed on the Changji-Guquan UHVDC transmission project, which is the highest voltage (<inline-formula><tex-math>$pm$</tex-math></inline-formula> 1100 kV), longest distance (3284 km), and largest capacity (rated 12100 MW) transmission project in the world. During its operation, the devices functioned correctly in several internal faults and external disturbance events. This work represents the first field validation of HVDC TWDP and bridges the gap between theoretical research and real-world applications. It confirms that TWDP can serve as the main protection for ultra-long-distance HVDC lines, setting a benchmark for future projects.","PeriodicalId":13498,"journal":{"name":"IEEE Transactions on Power Delivery","volume":"40 2","pages":"1078-1088"},"PeriodicalIF":3.8,"publicationDate":"2025-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143056533","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-29DOI: 10.1109/TPWRD.2025.3535712
Jianwen Zhang;Yedi Ji;Jianqiao Zhou;Yajun Jia;Gang Shi;Han Wang
With the integration of high proportion of distributed generation (DG), voltage violation may occur at the point of common coupling (PCC) of feeders in rural lower voltage distribution networks (LVDN). The DC link, with its advantages of large capacity and low line losses, can connect two or more feeders, facilitating broad area power and voltage regulation. At present, the voltage violation solutions based on DC link can be divided into communication-dependent and communication-less scheme. Given the randomness, rapidity, and real-time nature of voltage violation, communication-dependent solutions typically require fast, real-time communication, leading to high costs and significant resource consumption. Existing communication-less solutions, such as the voltage consensus method, while solving voltage violation, incur substantial power losses due to the need for real-time power interactions. This paper proposes a cooperative AC / DC voltage margin control scheme, which takes the DC voltage information as the medium, and can mitigate the voltage violation of rural LVDN under different operation conditions by coordinating the voltage source converters (VSCs) at the end of the feeders and energy storage system (ESS) without communication. In addition, by reasonably setting different AC and DC voltage thresholds, it can avoid unnecessary power interaction between different feeders and reduce the power loss. Finally, the feasibility and effectiveness of the proposed control strategy are verified by simulation.
{"title":"Cooperative AC/DC Voltage Margin Control for Mitigating Voltage Violation of Rural Distribution Networks With Interconnected DC Link","authors":"Jianwen Zhang;Yedi Ji;Jianqiao Zhou;Yajun Jia;Gang Shi;Han Wang","doi":"10.1109/TPWRD.2025.3535712","DOIUrl":"10.1109/TPWRD.2025.3535712","url":null,"abstract":"With the integration of high proportion of distributed generation (DG), voltage violation may occur at the point of common coupling (PCC) of feeders in rural lower voltage distribution networks (LVDN). The DC link, with its advantages of large capacity and low line losses, can connect two or more feeders, facilitating broad area power and voltage regulation. At present, the voltage violation solutions based on DC link can be divided into communication-dependent and communication-less scheme. Given the randomness, rapidity, and real-time nature of voltage violation, communication-dependent solutions typically require fast, real-time communication, leading to high costs and significant resource consumption. Existing communication-less solutions, such as the voltage consensus method, while solving voltage violation, incur substantial power losses due to the need for real-time power interactions. This paper proposes a cooperative AC / DC voltage margin control scheme, which takes the DC voltage information as the medium, and can mitigate the voltage violation of rural LVDN under different operation conditions by coordinating the voltage source converters (VSCs) at the end of the feeders and energy storage system (ESS) without communication. In addition, by reasonably setting different AC and DC voltage thresholds, it can avoid unnecessary power interaction between different feeders and reduce the power loss. Finally, the feasibility and effectiveness of the proposed control strategy are verified by simulation.","PeriodicalId":13498,"journal":{"name":"IEEE Transactions on Power Delivery","volume":"40 2","pages":"1014-1029"},"PeriodicalIF":3.8,"publicationDate":"2025-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143056534","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Glaze icing significantly increases the flashover probability of in-service insulators, making it the most hazardous icing type for overhead power lines. To automatically and accurately characterize the glaze icing state of suspension insulators susceptible to icicle bridging, this paper proposes a novel method for calculating icicle morphological parameters, including icicle distribution and bridging degree, using images from multi-perspective monitoring scenarios. The method first recognizes and segments images to focus on insulators, then uses gradient-contour analysis to correct axial tilt, locate shed units of different materials, and detect icicles between sheds. It utilizes the relative positions of shed units and icicles to quantify uneven and segmented icing phenomena and calculate the icicle bridging degree of the insulator string and shed units. Image analysis of 15 multi-view, multi-material, and varying-length suspension insulators demonstrates that this method achieves 98.8% precision in localizing 91 shed units and 94.6% precision in detecting 490 icicles. The accuracy in recognizing axial and circumferential icicle distributions is 91.2% and 98.9%, respectively, with precision surpassing 90% in calculating the icicle bridging degree. The method can finely parameterize icicles’ position and length, providing a solution for image-based diagnosis of distribution uniformity and bridging severity of glaze ice on insulators.
{"title":"Automatic Calculation of Icicle Morphological Parameters for Multi-Perspective Suspension Insulators Using Gradient-Contour Analysis","authors":"Wei Liang;Yanpeng Hao;Lei Huang;Zikui Shen;Zijian Wu;Lin Yang;Jinqiang He;Huan Huang","doi":"10.1109/TPWRD.2025.3536216","DOIUrl":"10.1109/TPWRD.2025.3536216","url":null,"abstract":"Glaze icing significantly increases the flashover probability of in-service insulators, making it the most hazardous icing type for overhead power lines. To automatically and accurately characterize the glaze icing state of suspension insulators susceptible to icicle bridging, this paper proposes a novel method for calculating icicle morphological parameters, including icicle distribution and bridging degree, using images from multi-perspective monitoring scenarios. The method first recognizes and segments images to focus on insulators, then uses gradient-contour analysis to correct axial tilt, locate shed units of different materials, and detect icicles between sheds. It utilizes the relative positions of shed units and icicles to quantify uneven and segmented icing phenomena and calculate the icicle bridging degree of the insulator string and shed units. Image analysis of 15 multi-view, multi-material, and varying-length suspension insulators demonstrates that this method achieves 98.8% precision in localizing 91 shed units and 94.6% precision in detecting 490 icicles. The accuracy in recognizing axial and circumferential icicle distributions is 91.2% and 98.9%, respectively, with precision surpassing 90% in calculating the icicle bridging degree. The method can finely parameterize icicles’ position and length, providing a solution for image-based diagnosis of distribution uniformity and bridging severity of glaze ice on insulators.","PeriodicalId":13498,"journal":{"name":"IEEE Transactions on Power Delivery","volume":"40 2","pages":"1002-1013"},"PeriodicalIF":3.8,"publicationDate":"2025-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143056600","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-28DOI: 10.1109/TPWRD.2025.3535497
Yunfei Jia;Xun Luo;Shengchang Ji;Shuangrui Jia;Simeng Li
Transformer's internal arc fault is one of its most serious faults, which might cause fire accidents. These accidents have caused widespread concern among scholars and indicated the importance of explosion-proof performance calibration. However, there is a lack of methods to estimate arc energy accurately. Within the gap length range of 5–100 mm, the current range of 1–10 kA, and the pressure range of 1–15 atm, this paper conducts 640 power-frequency arc experiments, the most numerous and well-organized experiments reported so far. An average arc voltage calculation method based on energy equivalence is proposed to avoid existing method bias and better fit the actual energy curve. Factors affecting the average arc voltage are analyzed. The relationship between the voltage and gap length approximates a linear function, and the relationship with pressure approximates a power function. An energy estimation method involving gap length and pressure is proposed. The errors of existing and proposed arc energy estimation methods are compared and reported for the first time. The proposed method dramatically reduces the average error from 43.6% to 11.5%. Repeatability experiments show that the discharge dispersion causes an average energy error of 9.1%, so the error of the proposed method is satisfactory.
{"title":"Energy Estimation Method for Power-Frequency Arc in Transformer Oil Based on Gap Length and Pressure","authors":"Yunfei Jia;Xun Luo;Shengchang Ji;Shuangrui Jia;Simeng Li","doi":"10.1109/TPWRD.2025.3535497","DOIUrl":"10.1109/TPWRD.2025.3535497","url":null,"abstract":"Transformer's internal arc fault is one of its most serious faults, which might cause fire accidents. These accidents have caused widespread concern among scholars and indicated the importance of explosion-proof performance calibration. However, there is a lack of methods to estimate arc energy accurately. Within the gap length range of 5–100 mm, the current range of 1–10 kA, and the pressure range of 1–15 atm, this paper conducts 640 power-frequency arc experiments, the most numerous and well-organized experiments reported so far. An average arc voltage calculation method based on energy equivalence is proposed to avoid existing method bias and better fit the actual energy curve. Factors affecting the average arc voltage are analyzed. The relationship between the voltage and gap length approximates a linear function, and the relationship with pressure approximates a power function. An energy estimation method involving gap length and pressure is proposed. The errors of existing and proposed arc energy estimation methods are compared and reported for the first time. The proposed method dramatically reduces the average error from 43.6% to 11.5%. Repeatability experiments show that the discharge dispersion causes an average energy error of 9.1%, so the error of the proposed method is satisfactory.","PeriodicalId":13498,"journal":{"name":"IEEE Transactions on Power Delivery","volume":"40 2","pages":"965-973"},"PeriodicalIF":3.8,"publicationDate":"2025-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143054944","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-28DOI: 10.1109/TPWRD.2025.3535785
Yunfeng Li;Tao Wen;Yijia Cao;Yuhang Zhang;Weiyu Wang
In the modular multilevel converter (MMC) based high voltage direct current (HVDC) practical projects, the existing voltage feedforward control (VFC) method presents challenges in addressing the frequency shift of high-frequency resonance (HFR) caused by the changes in the interconnected AC system's operating conditions. In this paper, the mathematical characterization function of the impedance real part is used to reveal the mechanism why the existing VFC cannot simultaneously reshape the multiple HFR risk regions into the positive damping characteristics. Therefore, a frequency divided voltage feedforward control (FDVFC) based on the second-order band-pass filters (BPFs) is proposed to simultaneously reshape the multiple HFR risk regions into the positive damping characteristics. The proposal includes the selection of the number of BPFs and how to design their parameters. The parameter design principles and parameter selection ranges of the BPFs are presented one by one using the simplified model of the MMC in high-frequency band. Finally, the effectiveness and correctness of the FDVFC and its analytical calculation expressions for parameter selection are verified by time-domain simulations.
{"title":"High-Frequency Resonance Coordinated Suppression Method of MMC-HVDC Systems Under Frequency Divided Voltage Feedforward Control","authors":"Yunfeng Li;Tao Wen;Yijia Cao;Yuhang Zhang;Weiyu Wang","doi":"10.1109/TPWRD.2025.3535785","DOIUrl":"10.1109/TPWRD.2025.3535785","url":null,"abstract":"In the modular multilevel converter (MMC) based high voltage direct current (HVDC) practical projects, the existing voltage feedforward control (VFC) method presents challenges in addressing the frequency shift of high-frequency resonance (HFR) caused by the changes in the interconnected AC system's operating conditions. In this paper, the mathematical characterization function of the impedance real part is used to reveal the mechanism why the existing VFC cannot simultaneously reshape the multiple HFR risk regions into the positive damping characteristics. Therefore, a frequency divided voltage feedforward control (FDVFC) based on the second-order band-pass filters (BPFs) is proposed to simultaneously reshape the multiple HFR risk regions into the positive damping characteristics. The proposal includes the selection of the number of BPFs and how to design their parameters. The parameter design principles and parameter selection ranges of the BPFs are presented one by one using the simplified model of the MMC in high-frequency band. Finally, the effectiveness and correctness of the FDVFC and its analytical calculation expressions for parameter selection are verified by time-domain simulations.","PeriodicalId":13498,"journal":{"name":"IEEE Transactions on Power Delivery","volume":"40 2","pages":"938-950"},"PeriodicalIF":3.8,"publicationDate":"2025-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143054945","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The intricate dynamics in renewables transmitted through modular multilevel converter based high voltage direct current (MMC-HVDC) may induce new low-frequency oscillation (LFO). This stability issue has not been deeply explored in existing literature. In light of this, this paper establishes a representative model of converter-interfaced generations (CIGs) with MMC-HVDC transmission. Then, eigenvalue-based analyses, time-domain simulations, and block diagrams are employed to investigate the mechanism and characteristics of the new LFO. For the first time, this paper indicates the coexistence of two LFO modes in such a system, which could become unstable simultaneously. The LFO modes mainly originate from the interaction among the phase-locked loop (PLL) of CIGs, DC voltage control of CIGs, and AC voltage control of MMC. These loops’ contributions to two LFO modes are sensitive to certain parameter settings. The paper further analyzes the key factors affecting LFO characteristics, including the control parameters of CIGs and MMC, and the number of online CIGs. Possible control measures for this new oscillation issue are also discussed.
{"title":"Investigation of New Low-Frequency Oscillation Caused by Converter-Interfaced Generations With MMC-HVDC Transmission","authors":"Jieyi Xu;Xiaorong Xie;Wenkai Dong;Peng Yu;Jiawei Xing","doi":"10.1109/TPWRD.2025.3535690","DOIUrl":"10.1109/TPWRD.2025.3535690","url":null,"abstract":"The intricate dynamics in renewables transmitted through modular multilevel converter based high voltage direct current (MMC-HVDC) may induce new low-frequency oscillation (LFO). This stability issue has not been deeply explored in existing literature. In light of this, this paper establishes a representative model of converter-interfaced generations (CIGs) with MMC-HVDC transmission. Then, eigenvalue-based analyses, time-domain simulations, and block diagrams are employed to investigate the mechanism and characteristics of the new LFO. For the first time, this paper indicates the coexistence of two LFO modes in such a system, which could become unstable simultaneously. The LFO modes mainly originate from the interaction among the phase-locked loop (PLL) of CIGs, DC voltage control of CIGs, and AC voltage control of MMC. These loops’ contributions to two LFO modes are sensitive to certain parameter settings. The paper further analyzes the key factors affecting LFO characteristics, including the control parameters of CIGs and MMC, and the number of online CIGs. Possible control measures for this new oscillation issue are also discussed.","PeriodicalId":13498,"journal":{"name":"IEEE Transactions on Power Delivery","volume":"40 2","pages":"1067-1077"},"PeriodicalIF":3.8,"publicationDate":"2025-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143054942","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper proposes two analytical valve-side single-phase-to-ground (SPG) fault calculation models for bipolar modular multilevel converter-based high-voltage direct current (MMC-HVDC) system. The first model is applicable to the half-bridge submodule (HBSM) configuration, and the second is suitable for the full-bridge submodules (FBSMs) or hybrid SMs with different FBSM ratios. In each calculation model, two post-fault equivalent MMC circuits are established following converter blocking for the independent study of the upper and lower arms. The detailed expression of the post-fault voltages and currents in each arm, valve-side, and grid-side are obtained from the proposed calculation models. Moreover, the applicability of the calculation models for solid, inductive, and resistive dc-grounding methods is also demonstrated, along with a further discussion on the influence of MMC arm/grid-side resistance as well as varying fault-grounding impedance. Multiple bipolar MMC-HVDC systems, incorporating HBSM, FBSM, and hybrid SM configurations, are developed in PSCAD/EMTDC to validate the accuracy of the proposed analytical calculation models.
{"title":"Analytical Calculation Models for Bipolar MMC-HVDC Systems Under Valve-Side Single-Phase-to-Ground Faults","authors":"Pingyang Sun;Gen Li;Hanwen Zhang;Jun Liang;Georgios Konstantinou","doi":"10.1109/TPWRD.2025.3535703","DOIUrl":"10.1109/TPWRD.2025.3535703","url":null,"abstract":"This paper proposes two analytical valve-side single-phase-to-ground (SPG) fault calculation models for bipolar modular multilevel converter-based high-voltage direct current (MMC-HVDC) system. The first model is applicable to the half-bridge submodule (HBSM) configuration, and the second is suitable for the full-bridge submodules (FBSMs) or hybrid SMs with different FBSM ratios. In each calculation model, two post-fault equivalent MMC circuits are established following converter blocking for the independent study of the upper and lower arms. The detailed expression of the post-fault voltages and currents in each arm, valve-side, and grid-side are obtained from the proposed calculation models. Moreover, the applicability of the calculation models for solid, inductive, and resistive dc-grounding methods is also demonstrated, along with a further discussion on the influence of MMC arm/grid-side resistance as well as varying fault-grounding impedance. Multiple bipolar MMC-HVDC systems, incorporating HBSM, FBSM, and hybrid SM configurations, are developed in PSCAD/EMTDC to validate the accuracy of the proposed analytical calculation models.","PeriodicalId":13498,"journal":{"name":"IEEE Transactions on Power Delivery","volume":"40 2","pages":"988-1001"},"PeriodicalIF":3.8,"publicationDate":"2025-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143054895","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：