Electric Power Systems Research最新文献

{"title":"A Frequency-domain pilot protection method considering instrument transformer characteristics","authors":"Jifei Yan,&nbsp;Pengfei Liu,&nbsp;Zhongxue Chang,&nbsp;Guobing Song,&nbsp;Xiaoping Gao","doi":"10.1016/j.epsr.2025.112191","DOIUrl":"10.1016/j.epsr.2025.112191","url":null,"abstract":"<div><div>The sensitivity of traditional current differential protection may decrease or even lead to maloperation due to the frequency deviation and limited amplitude characteristics of fault currents from power electronic-based power supplies. To solve aforementioned challenges, this study presents a fast frequency-domain pilot protection method based on line model consistency identification. This approach distinguishes between internal and external faults through transient voltage and current measurements while comprehensively accounting for the frequency response characteristics of instrument transformers. First, the mathematical relationships governing the secondary voltage and current under internal and external faults are rigorously established. Subsequently, the complex frequency-domain components of the transient voltage and current are extracted by applying of the numerical Laplace transform. Then, a consistency criterion for the line model is established, accompanied by a comprehensive protection scheme. Finally, extensive numerical simulations are conducted to validate the effectiveness of the method. Compared with existing approaches, the proposed method functions independently of the output power level of the power supplies at both ends and demonstrates superior robustness against high fault resistance and strong noise interference. In addition, the proposed method exhibits a light computational burden and requires low sampling rates.</div></div>","PeriodicalId":50547,"journal":{"name":"Electric Power Systems Research","volume":"251 ","pages":"Article 112191"},"PeriodicalIF":4.2,"publicationDate":"2025-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145061085","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Detailed electromagnetic transient model of switched reluctance motor drive system","authors":"Seyedarmin Mirnikjoo ,&nbsp;Mohammed Naidjate ,&nbsp;Jean Mahseredjian ,&nbsp;Nicolas Bracikowski ,&nbsp;Paul Akiki","doi":"10.1016/j.epsr.2025.112230","DOIUrl":"10.1016/j.epsr.2025.112230","url":null,"abstract":"<div><div>This paper focuses on the electromagnetic transient modeling of the switched reluctance motor drive system through the detailed circuit-based representation of the machine, power converter and control system. The dynamic model of the switched reluctance machine consists of interconnected mechanical, electrical and magnetic equivalent circuits in simultaneous solution. The mesh-based permeance network is used to model the nonlinear magnetic behavior of the rotor and stator while the airgap is modeled with variable permeances, enabling transient studies without re-meshing or reconnecting nodes during runtime. The accuracy of the proposed model is validated through comparison with a finite element-based model, demonstrating its reliability while offering significantly faster computational performance. The proposed model simulates the complete switched reluctance drive system under transient conditions.</div></div>","PeriodicalId":50547,"journal":{"name":"Electric Power Systems Research","volume":"251 ","pages":"Article 112230"},"PeriodicalIF":4.2,"publicationDate":"2025-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145061084","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dynamic equivalencing of power systems using bus impedance matrix","authors":"Mahesh Rathnayake ,&nbsp;Gayan Wijeweera ,&nbsp;Brian Archer ,&nbsp;Udaya Annakkage","doi":"10.1016/j.epsr.2025.112214","DOIUrl":"10.1016/j.epsr.2025.112214","url":null,"abstract":"<div><div>In real-time power system operations, frequent assessment of system operating limits for large, interconnected networks through dynamic simulations is critical for maintaining stability and reliability for system operators. To address the associated computational challenges and reduce simulation time, portions of the network must be represented using equivalent models. This paper introduces a methodology that involves solving a set of linear equations to develop equivalent models at regular intervals, reflecting real-time system conditions. The proposed structured and repeatable methodology facilitates the frequent updating of the external equivalent model while limiting the computational burden to practically acceptable levels. The dynamic simulation results for the study area, comparing the full system model and the reduced model derived through the proposed methodology, demonstrate a high degree of consistency. While the proposed methodology exhibits certain limitations, it also presents notable strengths, which can be further explored and refined to enhance the accuracy of the reduced model.</div></div>","PeriodicalId":50547,"journal":{"name":"Electric Power Systems Research","volume":"251 ","pages":"Article 112214"},"PeriodicalIF":4.2,"publicationDate":"2025-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145061087","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Realization of rational models for tower-footing grounding systems","authors":"Antonio C.S. Lima ,&nbsp;Thiago J.M.A. Parreiras ,&nbsp;Rafael Alípio ,&nbsp;Maria Teresa Correia de Barros","doi":"10.1016/j.epsr.2025.112222","DOIUrl":"10.1016/j.epsr.2025.112222","url":null,"abstract":"<div><div>A tower footing grounding system plays an essential role in lightning-related overvoltages. For time-domain analysis, using an Electromagnetic Transient (EMT) program, one typically has to resort to a rational approximation of the harmonic impedance or a frequency-dependent network equivalent (FDNE) for the grounding system. Although one may obtain a rational approximation in several ways, a discussion of the impact of the topology considered for the rational approximation and the effect of the effective length in this realization has not been presented in the literature. Thus, this work focused on these two aspects. First, a comparison of either approach regarding a minimum-order representation. Second, comparing the two possible topologies of the rational approximation order and its relationship with the effective length. The results indicate that an accurate FDNE is slightly more robust if the effective length is respected.</div></div>","PeriodicalId":50547,"journal":{"name":"Electric Power Systems Research","volume":"251 ","pages":"Article 112222"},"PeriodicalIF":4.2,"publicationDate":"2025-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145050218","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Research on power system frequency safety assessment method based on improved transformer","authors":"Jiaxu Li ,&nbsp;Junyong Wu ,&nbsp;Lusu Li ,&nbsp;Zhenyuan Zhang ,&nbsp;Fashun Shi","doi":"10.1016/j.epsr.2025.112248","DOIUrl":"10.1016/j.epsr.2025.112248","url":null,"abstract":"<div><div>With the ongoing development of power system and the widespread application of renewable energy, the complexity of power system in terms of electrical structure and dynamic characteristics is steadily increasing, presenting significant challenges to frequency safety. Accurately and efficiently assessing frequency safety is crucial, as it provides essential data support for emergency control strategies. Traditional assessment methods struggle to meet the demands for accuracy and responsiveness due to the intricateness of power system. However, advancements in artificial intelligence offer promising new avenues for frequency safety assessment. In this context, a model for assessing frequency safety in power systems is proposed, based on the improved Transformer. The proposed model enhances the Transformer’s feedforward network by integrating the convolutional residual structure of the Residual Neural Network (ResNet), thereby effectively combining the Transformer’s capability for sequential data processing with ResNet’s strength in feature extraction. This hybrid architecture significantly improves the overall assessment performance. Experimental evaluations on the IEEE 39-bus and Illinois 200-bus systems demonstrate that the proposed method surpasses conventional deep learning approaches in terms of accuracy, reliability, and false negative rate. Notably, the method provides rapid and precise frequency safety warnings, ensuring high accuracy and robustness.</div></div>","PeriodicalId":50547,"journal":{"name":"Electric Power Systems Research","volume":"251 ","pages":"Article 112248"},"PeriodicalIF":4.2,"publicationDate":"2025-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145050217","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Higher-order Newton-cotes and gauss-quadrature integration rules to solve carson and pollaczek integrals","authors":"J.A. Gutiérrez-Robles ,&nbsp;V.A. Galván-Sánchez ,&nbsp;E.S. Bañuelos-Cabral ,&nbsp;J.J. Nuño-Ayón ,&nbsp;J. Sotelo-Castañón ,&nbsp;C.A. López de Alba","doi":"10.1016/j.epsr.2025.112202","DOIUrl":"10.1016/j.epsr.2025.112202","url":null,"abstract":"<div><div>The problem of electromagnetic wave propagation, despite its importance, does not have a simple analytical solution. Therefore, approximations—such as assuming a semi-infinite homogeneous ground plane—are of practical interest. Using quasi-static approximations, Carson and Pollaczek derived integral equations to calculate the electromagnetic field produced by a horizontal current over a lossy ground plane. Carson proposed the first solution to these expressions using power series expansions, but this approach lacks uniform convergence. Since then, various efforts have been made to obtain more accurate solutions. In this sense, main approaches have been developed to solve these integral equations. The first involves modifying the integrand to obtain an analytic solution, while the second relies on using numerical integration techniques, which are essential for solving integrals without closed-form solutions. The accuracy of numerical methods is influenced by the choice of integration scheme, order, and number of samples. However, theoretical expectations of improved accuracy with higher-order methods and increased sample points are often limited by numerical representation constraints. One of this constrain is the finite bit representation in binary calculations. Despite these limitations, numerical methods remain the only viable approach for certain integrals. This work presents the implementation of Newton and Gauss integration methods, analyzing their performance concerning method type, order, and sample count. Since Carson and Pollaczek’s equations include a decreasing exponential term, the infinite upper limit is replaced by a finite bound without exceeding a predefined error threshold. By applying this limit substitution and numerical techniques, we obtain a new solution that ensures uniform convergence across all cases.</div></div>","PeriodicalId":50547,"journal":{"name":"Electric Power Systems Research","volume":"251 ","pages":"Article 112202"},"PeriodicalIF":4.2,"publicationDate":"2025-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145050219","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An innovative transformer fault diagnosis method based on ACK-GRANDE","authors":"Yongwen Li ,&nbsp;Bin Song ,&nbsp;Shaocheng Wu ,&nbsp;Deyu Nie ,&nbsp;Zisheng Zeng ,&nbsp;Linong Wang","doi":"10.1016/j.epsr.2025.112239","DOIUrl":"10.1016/j.epsr.2025.112239","url":null,"abstract":"<div><div>To address the limitations of existing DGA-based transformer fault diagnosis methods and further enhance fault diagnosis accuracy, this paper proposed a new transformer fault diagnosis method. First, during the pre-processing of DGA data, data cleaning was performed to remove anomalies and noise, and the Adaptive Synthetic Sampling Approach for Imbalanced Learning (ADASYN) algorithm was used to alleviate data imbalance, thereby improving data quality for subsequent diagnostics. Next, an improved model, referred to as ACK-GRANDE was proposed. The key optimization modules were divided into the following parts. Firstly, a refined feature weight allocation strategy was introduced, simulating a graph attention mechanism to adjust feature weights, avoid local optima, and enhance the ability to capture key information. Additionally, supplementary losses based on cosine similarity and Euclidean distance from K-Means clustering were incorporated, constructing a new loss function to enhance the model’s ability to recognize patterns in complex data. Finally, using 1200 DGA data samples with known fault types for case analysis, the results demonstrated that, compared to other traditional machine learning classification models, the proposed algorithm achieved higher accuracy in transformer fault diagnosis. The overall accuracy reached 93.75 %, exhibited superior long-term stability and broader applicability, and ablation experiments further validated the feasibility of each optimization module.</div></div>","PeriodicalId":50547,"journal":{"name":"Electric Power Systems Research","volume":"251 ","pages":"Article 112239"},"PeriodicalIF":4.2,"publicationDate":"2025-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145050564","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation of lightning effects on solar power plants connected to transmission networks","authors":"S. Grebovic ,&nbsp;A. Aksamovic ,&nbsp;B. Filipović – Grčić ,&nbsp;S. Konjicija","doi":"10.1016/j.epsr.2025.112217","DOIUrl":"10.1016/j.epsr.2025.112217","url":null,"abstract":"<div><div>The increasing integration of solar power plants into transmission grids has raised concerns about their vulnerability to disturbances, particularly lightning strokes. Solar energy, while offering significant environmental and economic benefits, faces challenges when connected to transmission lines that are prone to lightning discharges. This paper investigates the impact of lightning events on solar power plants, focusing on overvoltage effects. Lightning stroke simulations were conducted at various distances from the solar power plant along the transmission line, considering scenarios with and without surge arrester. Key lightning parameters such as peak current, front time, and tail time were varied to simulate different lightning strokes. The study also includes a Fourier transform analysis of the resulting overvoltages with and without a surge arrester, along with the Hilbert marginal spectrum of these overvoltages. The results provide insights into the effectiveness of surge arresters in mitigating lightning overvoltages and highlight the importance of proper protective measures for enhancing the reliability and safety of solar power plants connected to transmission networks.</div></div>","PeriodicalId":50547,"journal":{"name":"Electric Power Systems Research","volume":"251 ","pages":"Article 112217"},"PeriodicalIF":4.2,"publicationDate":"2025-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145050565","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact of concrete-encased grounding systems on lightning overvoltages in transmission lines","authors":"W.L.M. de Azevedo ,&nbsp;T.F.G. Pascoalato ,&nbsp;A.R.J. de Araújo ,&nbsp;S. Kurokawa ,&nbsp;J. Pissolato Filho","doi":"10.1016/j.epsr.2025.112227","DOIUrl":"10.1016/j.epsr.2025.112227","url":null,"abstract":"<div><div>This paper addresses the influence of concrete on the overvoltages developed in a 138-kV transmission line (TL) subjected to lightning strikes with variable amplitude. This study considers a tower-footing grounding system consisting of four counterpoise conductors, utilizing both bare and concrete-encased electrodes. The harmonic grounding impedance is initially calculated over a frequency range from 100 Hz to 10 MHz. Subsequently, the ground potential rise (GPR) developed by the tower-footing grounding system under lightning currents with adjustable peak values is analyzed. Furthermore, the impulse impedance is computed to model the tower-footing grounding system within the simulated power network. The TL is modeled using the Universal Line Model (ULM), which incorporates frequency-dependent (FD) soil parameters and ground-return parameters calculated via Nakagawa’s equations. Simulations are performed in ATP-EMTP, where the ULM is implemented in MATLAB and incorporated into the model via a PCH file. Finally, the overvoltage waveforms generated for the 138-kV power system subjected to a lightning strike are analyzed for three different values of low-frequency soil resistivity modeled using Alípio-Visacro’s approach: 700, 1500, and 4000 <span><math><mi>Ω</mi></math></span> m. The simulation results reveal a substantial reduction in harmonic impedance for the concrete-encased grounding system compared to the bare-electrode configuration. This reduction leads to lower impulse impedance and results in GPR waveforms with significantly reduced peak values when concrete is incorporated into the grounding system. However, in high-resistivity soils, the reduction achieved by the concrete-encased system is limited to approximately 33%. In addition, the overvoltages generated by lightning strikes are lower when the concrete-encased grounding system is used. In contrast, the bare grounding system leads to backflashover events, which do not occur when the concrete-encased grounding system is used.</div></div>","PeriodicalId":50547,"journal":{"name":"Electric Power Systems Research","volume":"251 ","pages":"Article 112227"},"PeriodicalIF":4.2,"publicationDate":"2025-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145050215","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation of resonance between HVDC-MMC link and AC network","authors":"Iva Radecic ,&nbsp;Bozidar Filipovic-Grcic ,&nbsp;Paul Akiki ,&nbsp;Alain Xémard ,&nbsp;Bruno Jurisic","doi":"10.1016/j.epsr.2025.112231","DOIUrl":"10.1016/j.epsr.2025.112231","url":null,"abstract":"<div><div>HVDC networks offer several advantages over traditional HVAC systems, particularly for long-distance power transmission and integration of renewable energy sources, such as reduced losses and enhanced stability and control, but also increase the risk of oscillations. This study investigates electrical resonant phenomena associated with HVDC stations through numerical EMT simulations. The findings indicate that electrical resonance is primarily pronounced in weak networks with long cables, as confirmed by the Nyquist criterion applied to frequency responses. Two real cases were successfully simulated in the time domain by introducing network changes, such as temporary faults and alterations in network’s power strength, to activate the identified resonances. Notably, in a strong network with short cables, electrical resonance occurred alongside interactions between the network and the converter's protection system. The analysis of voltage waveforms revealed that the amplitude of the induced resonant harmonic dissipates quickly, indicating sufficient damping in the network configuration. Furthermore, the study confirmed the network's sensitivity to changes in converter parameters modeled using available MMC model.</div></div>","PeriodicalId":50547,"journal":{"name":"Electric Power Systems Research","volume":"251 ","pages":"Article 112231"},"PeriodicalIF":4.2,"publicationDate":"2025-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145050211","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}