{"title":"Unified Impedance Model of Four-Port Network for Bipolar Overhead Lines in Parallel Multi-Terminal DC Transmission System","authors":"Shunliang Wang;Qi Yin;Tianyu Chang;Junpeng Ma;Hao Tu;Maolan Peng","doi":"10.1109/TPWRD.2025.3552637","DOIUrl":"10.1109/TPWRD.2025.3552637","url":null,"abstract":"There are various operating modes of parallel bipolar multi-terminal DC transmission systems, among which there is an asymmetric condition of unipolar-bipolar hybrid form. In this case, the distribution of harmonics on the line is different from the normal case, and the equivalent impedance of the mode-domain loops obtained by pole-mode transformation is changed. To solve the problem of harmonic analysis on the DC side under asymmetric conditions, a unified impedance model for bipolar DC overhead lines applicable to various conditions is proposed. Firstly, the decoupling model and equivalent circuit of the mode domain of bipolar symmetrical lines are explained. Then, the limitations of the mode-domain component superposition calculation method in the analysis with asymmetric conditions are revealed. On this basis, from the perspective of the dual input and dual output port network of bipolar DC lines, the four-port pole-mode conversion relationship and fourth-order transformation matrix of bipolar DC lines are proposed. A unified impedance model of four-port network for bipolar overhead lines is established. Finally, the simulation results based on PSCAD show that the proposed model can solve the harmonic transfer analysis and exhibit good reliability, with at least 5% reduction in the average relative error under asymmetric conditions.","PeriodicalId":13498,"journal":{"name":"IEEE Transactions on Power Delivery","volume":"40 3","pages":"1448-1458"},"PeriodicalIF":3.8,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143661492","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}
{"title":"Monitoring Conductor Sags for Dynamic Line Rating Based on Induced Signals in Overhead Ground Wires","authors":"Zherui Cui;Bo Zhang;Xiankang Wang;Yao Yao;Xueming Zhou","doi":"10.1109/TPWRD.2025.3550508","DOIUrl":"10.1109/TPWRD.2025.3550508","url":null,"abstract":"The sag information of conductors is important for dynamic line rating. This paper proposes a novel monitoring method for conductor sags based on the current or voltage in ground wires, which is produced by mutual inductance between conductors and ground wires. The devices of this method are easy to install and maintain, and the monitoring effect is not affected by bad weather such as snow and fog. To obtain sag information, a calculation method of induced signals in the ground wires is firstly proposed. Then the sensitivity of the induced signals in the ground wires to the variation of conductor sags is evaluated. The relationship between the induced signals in the ground wires and the sag information is established through neural network. A scaled test model of overhead transmission line is established to verify the proposed method. The accuracy of deduced results is acceptable.","PeriodicalId":13498,"journal":{"name":"IEEE Transactions on Power Delivery","volume":"40 3","pages":"1289-1297"},"PeriodicalIF":3.8,"publicationDate":"2025-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143607884","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}
{"title":"Perturbation- and Observation-Based Power Decoupling Method of Rotary Power Flow Controllers for Distribution Lines","authors":"Jiaoxin Jia;Weilin Wu;Chen Shao;Xiangwu Yan;Weifeng Peng;Xingping Yi;Hanzhu Sheng","doi":"10.1109/TPWRD.2025.3548440","DOIUrl":"10.1109/TPWRD.2025.3548440","url":null,"abstract":"The rotary power-flow controller (RPFC) is capable of regulating line power flow. However, the traditional RPFC power-decoupling method is associated with power coupling issues in high-resistance-ratio lines. To address these issues, this study investigates an RPFC power-decoupling method for high-resistance-ratio lines. First, the power-coupling relationship of RPFC is analyzed based on the power-regulation model after integration with RPFC. Different power flow contour lines are plotted using different line impedance parameters, and the response characteristics of line flow to the two phase-shifting angles are investigated. Second, a dual-input-dual-output perturbation and observation method aiming at RPFC power decoupling is proposed to achieve power decoupling control, which involves perturbing two phase-shifting angles and determining the next regulation direction based on the changes in power before and after the perturbation. Finally, the proposed and traditional methods are compared based on experimental validation tests on the 380V/40kVA RPFC test platform. The experimental results show that the proposed control strategy demonstrates good decoupling effects under different resistance-reactance ratio conditions, thereby verifying the correctness and effectiveness of the established model and control strategy.","PeriodicalId":13498,"journal":{"name":"IEEE Transactions on Power Delivery","volume":"40 3","pages":"1400-1410"},"PeriodicalIF":3.8,"publicationDate":"2025-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143607885","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}
Mingshun Ma;Jianwen Wu;Wei Zhao;Tangjun Xu;Yanxi He
{"title":"Research on the Operating Mechanism of 220 kV Circuit Breaker Motor Controlled by MPC+PID","authors":"Mingshun Ma;Jianwen Wu;Wei Zhao;Tangjun Xu;Yanxi He","doi":"10.1109/TPWRD.2025.3547692","DOIUrl":"10.1109/TPWRD.2025.3547692","url":null,"abstract":"The direct drive circuit breaker by permanent magnet synchronous motor is a new servo technology that can drive the moving contact to complete the opening and closing operation along the optimal path. A 220 kV double break operation model considering servo motor control is proposed to address the challenges of difficult opening, fast closing speed, and sudden changes in load torque of 220 kV vacuum circuit breakers. This study designed a circuit breaker opening planning curve based on the opening characteristics of the circuit breaker, and constructed kinematic and dynamic models of high-power switches and transmission mechanisms to determine the maximum torque, rated capacity, and performance characteristics required by the motor when the circuit breaker is opened. In addition, a permanent magnet synchronous motor model considering time-varying inertia was constructed using Matlab/Simulink software. This article proposes a model predictive control (MPC) + PID motor control model for multi-stage optimization control of stroke curves. The results show that the designed motor operating mechanism model meets the technical requirements of the arc extinguishing chamber operating mechanism, and the stroke curve gap distance is less than 5%. Compared with PID control alone, this method has more accuracy and stability.","PeriodicalId":13498,"journal":{"name":"IEEE Transactions on Power Delivery","volume":"40 3","pages":"1305-1317"},"PeriodicalIF":3.8,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143570409","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}
{"title":"Research on Electromagnetic Interference Signal Characteristics and Suppression Methods for High Frequency Partial Discharge Monitoring in Renewable Energy Stations","authors":"Zhiguo Tang;Ke Zhang;Wei Li;Bo Qi;Shusheng Zheng;Junkang Chen;Xuanhao Tang","doi":"10.1109/TPWRD.2025.3547345","DOIUrl":"10.1109/TPWRD.2025.3547345","url":null,"abstract":"As China's energy transformation advances, the proportion of renewable energy power generation in the power system continues to increase. 35 kV power cables are widely used as collector lines in renewable energy stations. High frequency (HF) partial discharge (PD) online monitoring is an important means to discover potential insulation defects in power cables and evaluate their operational status. Compared with traditional power stations, renewable energy stations use a large number of power electronic equipment, which can generate severe HF and high intensity pulse interference. These interferences are prone to submerging weak PD signals, posing new and severe challenges to high-frequency PD detection. Based on the engineering practice of Ulanqab Renewable Energy Station, this paper conducts actual measurement research on high-frequency electromagnetic interference signals in the station. According to the topological wiring of the station, the source and characteristics of the interference signals are studied through multi-point synchronous comparison testing. According to the time-frequency characteristics of the signal, a pulse extraction method based on OTSU and local energy threshold is proposed. Then, according to the extracted large number of pulses, a repetitive pulse interference separation method based on spectral clustering was proposed, which successfully separated several similar pulses from field data. On this basis, combined with stencil test, each pulse interference signal is identified and separated one by one, thus achieving the strategy of eliminating high-frequency and strong repetitive pulse interference signals. Verified with field data, the interference suppression rate reached 93.67%, proving the feasibility of this strategy.","PeriodicalId":13498,"journal":{"name":"IEEE Transactions on Power Delivery","volume":"40 3","pages":"1390-1399"},"PeriodicalIF":3.8,"publicationDate":"2025-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143546260","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}
{"title":"A Power Transformer Fault Diagnosis Method Based on Improved Variational Quantum Shadow Learning","authors":"Hongying He;Jiangchun Yu;Wei-Jen Lee;Diansheng Luo;Wenju Liang","doi":"10.1109/TPWRD.2025.3546722","DOIUrl":"10.1109/TPWRD.2025.3546722","url":null,"abstract":"An improved variational quantum shadow learning (VQSL) method is presented for the fault diagnosis of transformers. Localized variational quantum circuits for shadow feature extraction and a fully connected neural network are designed. Firstly, the dissolved gas analysis data is mapped into a high-dimensional Hilbert space, then, shadow features between adjacent and non-adjacent quantum bits are extracted simultaneously by multiple localized quantum circuits through parameter sharing, which reduces the number of training parameters and improves the model accuracy. The key factors that influence the performance of the VQSL method are discussed, which include quantum coding methods, the width and the depth of localized quantum circuits, the size of the global quantum bits, and the noise levels. Experimental results indicate that the improved VQSL method achieves a diagnostic accuracy of 95.4%, surpassing the commonly used methods such as QNN, GNN, CNN, SAE, SVM, and ratio methods. Even in a noise interference situation, the proposed method consistently maintains a high fault diagnosis accuracy.","PeriodicalId":13498,"journal":{"name":"IEEE Transactions on Power Delivery","volume":"40 3","pages":"1331-1343"},"PeriodicalIF":3.8,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143518680","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}
Guoteng Wang;Ying Huang;Zheng Xu;Feng Li;Ruoping Liu
{"title":"Dynamic Frequency Trajectory Prediction Assisted Frequency Response Method for Lightweight MTDC Systems","authors":"Guoteng Wang;Ying Huang;Zheng Xu;Feng Li;Ruoping Liu","doi":"10.1109/TPWRD.2025.3545432","DOIUrl":"10.1109/TPWRD.2025.3545432","url":null,"abstract":"This paper proposes a dynamic frequency trajectory (DFT) prediction assisted frequency response method (FRM) for the diode rectifiers (DR) and modular multilevel converters (MMC) based lightweight multi-terminal direct current (MTDC) systems. First, an improved state-space primary frequency regulation (SSPFR) model is established. Different from the existing primary frequency regulation (PFR) models, the proposed SSPFR model has fully considered spatial frequency distribution. Next, to cope with the prediction task of the DFT under continuous disturbances (CD-DFT), a novel CD-DFT prediction method based on the modal analysis is proposed, by which the prediction timeliness can be significantly improved. Then, the DFT assisted FRM is proposed, for improving the PFR performance of the lightweight MTDC systems while ensuring security operation. Finally, the proposed method is verified on a modified IEEE 39-bus system. The numerical results demonstrate that the proposed method can effectively exploit the frequency regulation potentialities of offshore wind farms connected to the lightweight MTDC system.","PeriodicalId":13498,"journal":{"name":"IEEE Transactions on Power Delivery","volume":"40 3","pages":"1365-1378"},"PeriodicalIF":3.8,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143518826","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}
{"title":"LARSI-TPE-XGB: Short-Term Load Forecasting by Load-Adaptive Relative Strength Index and Fusion of Tree-Structured Parzen Estimator and XGBoost","authors":"Jin-Xian Liu;Jenq-Shiou Leu","doi":"10.1109/TPWRD.2025.3545638","DOIUrl":"10.1109/TPWRD.2025.3545638","url":null,"abstract":"Power load forecasting is essential for optimizing power generation and distribution efficiency. This paper proposes a novel method for daily average load forecasting, referred to as LARSI-TPE-XGB, which integrates the Load-Adaptive Relative Strength Index (LARSI) with the Tree-structured Parzen Estimator (TPE) and eXtreme Gradient Boosting (XGBoost). Our method significantly improves the accuracy and generalization ability of short-term load forecasting (STLF) by addressing limitations in feature extraction and hyperparameter optimization. The proposed LARSI enhances the forecasting model by adapting an improved Relative Strength Index (RSI) for power load prediction, while TPE optimizes the model's hyperparameters to dynamically adjust to time-series updates, thus mitigating the issue of XGBoost's sensitivity to hyperparameters in high-dimensional scenarios. Experimental results on real-world power load datasets demonstrate that LARSI-TPE-XGB reduces errors by 18.58% and 30.73% in root mean squared error (RMSE) across two different datasets compared to models without LARSI-TPE-XGB and outperforms state-of-the-art models, as confirmed by the Diebold-Mariano (DM) test. Our method consistently improves performance across various datasets, while we further investigate the influence of LARSI and other factors, such as weather conditions, on forecasting accuracy.","PeriodicalId":13498,"journal":{"name":"IEEE Transactions on Power Delivery","volume":"40 3","pages":"1318-1330"},"PeriodicalIF":3.8,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143495297","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}
{"title":"The Influence of the Geoelectric Coast Effect on Geomagnetically Induced Currents","authors":"Darcy R. Cordell;Martyn J. Unsworth","doi":"10.1109/TPWRD.2025.3544488","DOIUrl":"10.1109/TPWRD.2025.3544488","url":null,"abstract":"Geomagnetically induced currents (GICs) in power networks can damage transformers, cause voltage instability and lead to power outages. GICs are driven by an induced voltage in transmission lines due to the induced surface geoelectric field component parallel to the line. It is well-known that an electrically conductive ocean can increase the geoelectric field magnitude on the landward side of the coast. However, limited work has been done to elucidate how the adjacent ocean impacts network GICs. We model GICs using a well-known network model situated adjacent to an ocean. Contrary to the notion that GIC risk is higher in coastal areas, we show that the ocean can cause a decrease in the maximum possible GIC in coastal power networks relative to calculated GICs which exclude coast effects, while increases in GIC due to the ocean can be relatively modest. This is because the geoelectric field only increases in the component perpendicular to the coast but decreases parallel to the coast. Thus, transmission lines parallel to coastlines experience a net decrease in induced voltage along their entire length, while transmission lines perpendicular to coastlines experience an increase in induced voltage that is self-limited by the distance from the coast.","PeriodicalId":13498,"journal":{"name":"IEEE Transactions on Power Delivery","volume":"40 3","pages":"1379-1389"},"PeriodicalIF":3.8,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143470773","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}
Guillermo A. Diaz;Hans K. Høidalen;Enrique E. Mombello;Camilo A. Cortes
{"title":"Implementation of the State-Space Power Transformer Model in ATP for High Frequency Transient Studies","authors":"Guillermo A. Diaz;Hans K. Høidalen;Enrique E. Mombello;Camilo A. Cortes","doi":"10.1109/TPWRD.2025.3544827","DOIUrl":"10.1109/TPWRD.2025.3544827","url":null,"abstract":"State-space representation is a practical, efficient and reliable way to evaluate the high-frequency interaction of a transformer with the power network under different types of disturbances. Currently, this representation is available in commercial electromagnetic transient programs; however, this important tool is not yet implemented in the alternative transient program ATP. This paper describes the implementation methodology of the state-space model of the power transformer in ATP using the Norton type-94 component and foreign models. The proposed implementation incorporates several aspects relevant to its application in realistic situations, including initialization from steady state, customization of information exchange between the manufacturer and the purchaser, and accurate consideration of damping. The implemented model in ATP is validated on a real 50 MVA power transformer by means of three relevant example cases, obtaining an excellent agreement between the reference data and those calculated with ATP.","PeriodicalId":13498,"journal":{"name":"IEEE Transactions on Power Delivery","volume":"40 3","pages":"1344-1352"},"PeriodicalIF":3.8,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143471086","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}