Current Issue: Volume 40, Issue 5 (2025)

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Optimal planning strategies for power grid topology Steiner minimum tree to enhance resilience capability
Yunpeng ZHAI, Dongqi LIU, Haolan LIANG, and Wei LI

Date posted: 12-18-2025
DOI: https://doi.org/10.19781/j.issn.1673-9140.2025.05.001

Energy security is related to the overall situation of economic and social development.In recent years, deliberate attacks and disasters against the power grid have occurred frequently, and the power system has become an important target of attacks in international conflicts.In order to enhance the ability of the power grid to resist deliberate attacks and disasters and ensure the safe operation of the national energy infrastructure, a Steiner minimum tree planning method is proposed for the power supply network topology to the improvement of invulnerability.Firstly, the grid structure strength index and operation vulnerability index are designed for the grid planning problem.A dual-layer planning model is constructed with the grid structure strength, network connectivity, and network operation status as the upper targets, and the line investment cost, node construction cost, and network loss cost as the lower targets.Secondly, based on the complex network theory, the topology mapping model of the power grid is built.The important areas and nodes of the power grid are divided according to the load demand and capacity demand of nodes.Then, the problem of power grid planning is transformed into a regional Steiner tree problem, and nodes are added in the region to re-plan the grid structure in important areas.Finally, the heuristic algorithm is combined with the mathematical programming problem.The artificial fish swarm algorithm is used to optimize the solution.The 39-node grid structure is applied for simulation verification.The calculation results show that the proposed method can improve the strength of the grid structure by 64.60% and reduce the operation risk by 71.38 %.

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Transformer data anomaly detection method based on feature extraction and AHC
Lina HUANG, Jinpeng QI, Li DAI, Yangyang GUO, Siyuan PENG, and Tairan WANG

Date posted: 12-18-2025
DOI: https://doi.org/10.19781/j.issn.1673-9140.2025.05.002

Dissolved gas analysis （DGA） is an important indicator for evaluating the operating status of transformers, and its abnormal changes can indicate potential faults.To solve the problems of redundancy, missing data, and isolated noise in transformer monitoring data, a transformer data anomaly detection （AD） method based on feature extraction and agglomerative hierarchical clustering （AHC） is proposed.Firstly, the missing data in the DGA ’s gas concentration data are supplemented and corrected by mean interpolation, followed by Z-score normalization.Secondly, the improved sliding window strategy and time series transformation （TST） algorithm are adopted to extract features from the data and construct the feature matrix.Finally, a density-based AHC method is employed for clustering, and the operating status of transformers is comprehensively analyzed based on the clustering results.The experimental results show that the accuracy of this method in identifying abnormal transformer operating status can reach 98.91%, which is 11.06 percentage points and 8.50 percentage points higher than that of the Fixed-TST algorithm and k-nearest neighbor （kNN） algorithm, respectively.This indicates that this method can effectively extract key features, reduce data complexity, and provide an analytical approach for transformer fault early warning.

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Active step-down arc suppression method for grounding faults in distribution network based on Dy transformer line voltage feed-in
Jisheng HUANG, Hongwen LIU, Zhihai HE, Zhengya LUO, Xijiang QU, Kun YU, and Zijian ZHOU

Date posted: 12-18-2025
DOI: https://doi.org/10.19781/j.issn.1673-9140.2025.05.003

To improve the applicability and reliability of an active step-down arc suppression method for grounding faults in a distribution network and solve the inherent contradiction between fault transfer technology and active arc suppression technology of power electronic devices in arc suppression effect and cost control, an active step-down arc suppression method for grounding faults in the distribution network based on Dy transformer line voltage feed-in is proposed.By application of the constant secondary side line voltage of the Dy transformer before and after the grounding fault and through switching of the corresponding line voltage feed-in switch on the secondary side of the transformer, the reverse voltage of the fault phase is fed into the neutral point, and the fault voltage is actively reduced to realize the step-down and arc quenching of grounding faults.At the same time, the offset characteristics of the neutral feed voltage caused by the internal impedance of the grounding transformer in the distribution network are further analyzed.The phase compensation between the transformer feed-in voltage and the fault phase voltage is realized by optimizing the transformer tap ratio.Therefore, the influence of the phase offset of the feed-in voltage caused by the internal impedance of the grounding transformer is eliminated.To verify the effectiveness of the proposed method, a typical model for grounding faults in the distribution network is built in power system computer aided design （PSCAD） simulation environment for experimental analysis.The simulation results show that the active step-down arc suppression method for grounding faults in the distribution network based on Dy transformer line voltage feed-in can effectively reduce the fault voltage and eliminate the residual current of grounding faults, thereby realizing reliable arc suppression of grounding faults.

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Research on distribution network reconstruction based on k-NN hybrid genetic algorithm
FU LI, Zhi ZHANG, Jiawei DING, and Kun WANG

Date posted: 12-18-2025
DOI: https://doi.org/10.19781/j.issn.1673-9140.2025.05.004

In the case of widespread access to distributed generation, in order to meet the radial topology constraints of the network, the distribution network topology constraints and other constraints are considered, and a distribution network reconfiguration method based on a k-NN hybrid genetic algorithm is proposed.First, the minimum network loss, load balance, and the minimum number of circuit breaker actions are used as the objective function.The mathematical model of distribution network reconfiguration is constructed under the constraints of the power flow equation, load balance, voltage ceiling, and power ceiling.The k-NN algorithm is used to ensure that the chromosomes always meet the radial constraints of the distribution network topology in crossover and mutation.Finally, a hybrid genetic algorithm based on the k-NN algorithm is established to solve the mathematical model and realize the topology reconstruction of the distribution network.Simulation results show that the proposed method can solve the reconstruction scheme and has certain applicability.

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Day-ahead and intra-day coordinated optimal scheduling for photovoltaic active distribution networks based on SARIMA prediction model
Yang ZHAO, Zhifang HAO, Cong WANG, Xiaolin TAN, Zihao ZHAO, Wei GUO, and Wenyi FAN

Date posted: 12-18-2025
DOI: https://doi.org/10.19781/j.issn.1673-9140.2025.05.005

A day-ahead and intra-day two-stage op timal scheduling method for active distribution networks based on the seasonal autoregressive integral moving average （SARIMA ） prediction model is proposed to solve the problem that the scheduling of traditional photovoltaic （PV） active distribution networks cannot fully mine the historical data of distributed PV output.Meanwhile, the affine relationship between distributed PV output prediction and distribution network optimal scheduling is established.Firstly, the historical data of distributed PV output are adopted to construct the interval boundary for PV output based on SARIMA prediction confidence level, thus forming the optimization interval for the uncertainty optimization problem.Then, by establishing the affine mechanism between confidence level and decision variables, a day-ahead and intra-day two-stage optimal scheduling model for distribution networks is built, where the optimization problem is transformed into a mixed integer programming problem for solution via the linear relaxation of affine variables.Finally, the effectiveness of the proposed method is verified by the improved IEEE 33-node distribution system, with the operation costs of the system at different confidence levels compared.

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Single-phase grounding fault line selection method for active distribution network with energy storage power stations
Xiaoran WANG, Chunju FAN, Yan HU, Haoyu ZHU, Hulin LIU, Hai YE, Zhongping LIU, and Yong HOU

Date posted: 12-18-2025
DOI: https://doi.org/10.19781/j.issn.1673-9140.2025.05.006

With the continuous integration of large-scale new energy, the scale of power grids and distribution networks is constantly expanding.Due to the large number of power electronic devices in the grid, the traditional fault line selection scheme for small current grounding systems can hardly ensure the line selection accuracy.To solve this problem, the fault characteristics of active distribution networks with energy storage power stations when single-phase grounding faults occur are analyzed, namely the different fault characteristics during the charging and discharging of energy storage power stations and the distribution characteristics of single-phase grounding fault current in resonant grounding systems.Then, a fault line selection method that actively injects characteristic electrical quantities based on the control strategy of energy storage power stations is proposed.Then, a detailed analysis and research on the injection quantity frequency selection method suitable for high-precision fault line selection is conducted, including the control strategy of energy storage power stations and its parameter selection principle.Finally, a line selection criterion based on the 10 Hz component in the zero-sequence current is proposed.The PSCAD/EMTDC simulation verifies the effectiveness of the energy storage power station control strategy, the correctness of the fault line selection theory, and the effectiveness of the scheme implementation.

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Load elasticity analysis of high-penetration micro photovoltaic distribution network based on three-phase unbalanced power flow
Jianglong LI, Jun XIAO, Wen ZHAO, Wei LI, Yankai ZHAO, Yongzhi LI, Yuchao LIU, and Licheng YAN

Date posted: 12-18-2025
DOI: https://doi.org/10.19781/j.issn.1673-9140.2025.05.007

Due to the fluctuation and uncertainty of the output of micro photovoltaics, their connection will have an impact on the load characteristics of the distribution network.To address this issue, a static load elasticity modeling method is proposed for high-penetration photovoltaic microgrid distribution networks.Firstly, a three-phase unbalanced power flow algorithm is adopted based on backward scanning to handle the changes in the static load model through the concept of elasticity.Meanwhile, in light of the elastic variation range of residential load, a random variation method is employed, and a Monte Carlo method based on the Gaussian normal distribution is used for random calculation to obtain the voltage amplitude and phase of each busbar.In addition, a group of scenarios are set up to evaluate different seasons, weeks, and time periods within a day.The research results indicate that during the noon period of summer, due to the high penetration and output characteristics of photovoltaic power generation, the distribution network is prone to high voltage.During the peak load period at night in winter, however, due to the increase in load demand, the voltage may approach or even drop to an acceptable minimum limit.

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Secure communication scheme for power lines based on OFDM-IM
Fang CHEN, Sihao ZHU, Weijie YANG, Guixian CHENG, and Zhou DAI

Date posted: 12-18-2025
DOI: https://doi.org/10.19781/j.issn.1673-9140.2025.05.008

To address the illegal eavesdropping problem caused by the openness of power line communication （PLC） channels, a physical-layer secure transmission scheme, namely artificial noise added orthogonal frequency division multiplexing with index modulation （AN-added OFDM-IM ）, is proposed from the perspective of physical-layer security for wiretap PLC channels.In this scheme, the index bits are still transmitted through the states of carriers, and the modulated bits are still transmitted via active carriers, while the idle inactive carriers are used to transmit artificial noise （AN） generated based on the channel state information （CSI） between legitimate links.The secure transmission rate of the proposed scheme over PLC channels is derived.Simulations are conducted on the secure rate and bit error rate of the network under various scenarios.Simulation results show that the scheme can not only improve the security of PLC networks but also maintain a good bit error rate.

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Improved FCM load clustering method based on C-SVD dimensionality reduction
Jinwei WAN, Jie XING, Yinghao SHAN, Beiyu JIN, and Meiqian HOU

Date posted: 12-18-2025
DOI: https://doi.org/10.19781/j.issn.1673-9140.2025.05.009

Daily load data clustering is an important method for analyzing and extracting users ’ electricity consumption characteristics.The indicator weights of the dimensionality-reduced sampling data for clustering will affect the clustering results.Therefore, a daily load data clustering method based on the integration of the CRITIC weighting singular value decomposition （SVD） dimensionality reduction method （C-SVD） with an improved weighted fuzzy C-means （FCM） algorithm is proposed.Meanwhile, to solve the problem that traditional FCM is susceptible to the initial clustering centers, an adaptive initial clustering center determination method called density-distance center selection （DDCS） is proposed.Firstly, SVD is adopted to perform dimensionality reduction on the load data.Then, the CRITIC weighting method is used to configure weights for the dimensionality-reduced indicators.Then, the DDCS method is utilized to determine the initial clustering centers.Finally, the weighted FCM algorithm is applied to cluster the load data.Simulation examples show that, compared with traditional methods, the proposed method has strong robustness and can significantly improve the accuracy of load data clustering results.

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Optimal scheduling strategy of frequency regulation for electric vehicle battery swapping stations based on user swapping adaptive model
Chenhao MIAO, Meixia ZHANG, Xiu YANG, and Wenlong LI

Date posted: 12-18-2025
DOI: https://doi.org/10.19781/j.issn.1673-9140.2025.05.010

As fast energy supply stations, electric vehicle （EV） battery swapping stations （BSS） meet EV energy demand and support power system frequency regulation services.To address the issues of EV scheduling and participation in grid FM, a two-phase EV BSS frequency regulation optimal scheduling strategy considering the user swapping adaptive model is proposed, aiming to improve the BSS economy.Firstly, a price mechanism model is designed for battery swapping at the BSS.A swapping adaptive model is built based on the battery's state of charge （SOC）, the battery ’s state of health （SOH）, and the user ’s satisfaction.Then, the BSS cluster is modeled to participate in frequency regulation （FR）, and a two-stage operation strategy is developed.The day-ahead strategy focuses on the optimal operation economy and arranges the battery charging plan and the frequency regulation plan, including the adjustable capacity calculation of the BSS and the power allocation of the battery packs.The intra-day strategy ensures the coordination between the battery swapping service and the FR service based on the real-time data ’s power allocation decision of the FR signals, with the goal of maximizing the net revenue.Simulation shows that this strategy effectively improves the operation economy while ensuring the battery swapping demand.

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Short-term prediction model for PV coupled with WRF-Solar and irradiance correction
Bin LI, Yi DING, Zhe BAO, Yu SONG, and Wei LI

Date posted: 12-18-2025
DOI: https://doi.org/10.19781/j.issn.1673-9140.2025.05.011

As the depletion of traditional fossil energy becomes more serious, the use of solar energy for photovoltaic power generation has been an important direction for global countries to adjust their energy structure.There is an urgent need to improve the prediction accuracy of photovoltaic power generation capacity.A short-term prediction model for photovoltaics （PV） coupled with a weather research and forecasting model for solar energy （WRF-Solar ） and irradiance correction is proposed to enhance the accuracy and reliability of short-term prediction of photovoltaic power.Firstly, WRF-Solar is used for numerical prediction of dynamic downscaling weather to obtain future meteorological factors, including irradiance.Then, a random forest （RF） is used to correct the predicted irradiance.On this basis, long-term and short-term neural networks, backpropagation neural networks, and stepwise cluster analysis are employed to establish a short-term prediction model for photovoltaic power.Finally, the actual operation data of a 40 MW photovoltaic power station is used to compare the models.The results show that the irradiance corrected by the RF model is closer to the real value, and the average absolute error rate is reduced by 56.06 percentage points.Compared with the prediction results of the other two models, the model of long-term and short-term neural networks demonstrates the best prediction effect, and the meaan absolute percentage error is increased by 4.13 percentage points, indicating that the combined model can further improve the accuracy of power prediction.

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Sub-synchronous oscillation suppression strategy for weak AC grid-connected systems of direct drive wind turbines based on dual phase-locked loop compensation current
Zewen LI, Dexuan JIAO, Guolin DING, Guorui WU, Yazi LUO, Hu XIAO, and Yuanchuan WANG

Date posted: 12-18-2025
DOI: https://doi.org/10.19781/j.issn.1673-9140.2025.05.012

The dynamic interaction between the control system of direct drive wind turbines and weak AC lines can easily cause sub-synchronous oscillations.Therefore, a sub-synchronous oscillation suppression strategy based on dual phase-locked loop （PLL） compensation current is proposed.By derivation of the transfer function model of the system, the influence of the interaction between the wind turbine control system and the AC line on the stability of the grid-connected system is analyzed, and the mechanism of sub-synchronous oscillation of the system is revealed.On the basis of traditional additional sub-synchronous damping control （SSDC）, the phase disturbance of the PLL is considered, and a compensation current is introduced into the voltage outer loop control system of the grid side converter （GSC） of the wind turbine through a dual PLL.This aims to weaken the interaction process that causes sub-synchronous oscillation between the GSC of the wind turbine and the AC line, thereby suppressing the sub-synchronous oscillation.The simulation results verify the suppression effect of the proposed method under the conditions of changes in power grid intensity and wind speed.

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Sub-synchronous oscillation detection in wind power systems based on PMSST
Zhijian LIU, Cheng TANG, Ruixin LI, Hang DONG, and Jikai CHEN

Date posted: 12-18-2025
DOI: https://doi.org/10.19781/j.issn.1673-9140.2025.05.013

In recent years, the rapid development of wind power has increasingly complicated the operation of power systems, with a higher risk of sub-synchronous oscillations （SSO）.The accurate and quick detection of SSO is highly important for effective countermeasures.However, the existing methods often exhibit poor noise adaptability and modal overlapping.To address these limitations, this paper proposes the parameterized multi-synchrosqueezing transform （PMSST）, which combines weighted least squares, multi-synchrosqueezing transform, and polynomial chirp transform.PMSST first applies the multi-synchrosqueezing transform to achieve a high-energy-concentration time-frequency representation.The instantaneous frequency ridges of component signals are then extracted by ridge extraction algorithms, and Weighted Least Squares is employed to estimate the parameters of the transformation kernel.Finally, the time-frequency spectra are reconstructed to enhance the signal's energy representation, and rotation-invariant techniques are employed for parameter identification.According to simulation results, based on digital signals and doubly fed induction generator （DFIG） SSO simulations, PMSST effectively suppresses noise, accurately decomposes SSO signals, and yields reliable parameter identification.

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Analysis of wideband oscillation of grid-connected PMSGs based on additional matching control and its adaptive suppression method
Yunlong JIANG, Juan LI, Jian LIU, Mingming SHI, and Chenyu ZHANG

Date posted: 12-18-2025
DOI: https://doi.org/10.19781/j.issn.1673-9140.2025.05.014

The wideband power oscillation caused by the interaction between permanent magnet synchronous generators （PMSGs） and the AC system seriously threatens the safe and stable operation of the grid.In response to the problem that most existing oscillation suppression methods are designed for specific operating conditions and oscillation modes, and have insufficient wideband adaptability, this paper proposes a wideband oscillation suppression method for PMSGs based on additional matching control.This method first identifies the dominant sequence component of the system, and then generates an additional phase signal from the oscillation component of the DC bus voltage through an additional matching controller.Finally, the phase output by the phase-locked loop （PLL） is added to the output phase of the additional matching controller as the actual reference phase.The additional matching controller does not rely on specific models, parameters, and operating conditions.It has a simple structure and can be applied to oscillation suppression in different frequency bands and modes.Impedance analysis, eigenvalue analysis, and time-domain simulation have verified the oscillation suppression effect of the proposed method.The results show that the proposed additional matching control method can effectively suppress oscillations under different operating conditions.

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Research review on fire safety management of grid-side electrochemical energy storage power stations in new power systems
Xinghang WENG and Sheng SU

Date posted: 12-18-2025
DOI: https://doi.org/10.19781/j.issn.1673-9140.2025.05.015

The grid-side electrochemical energy storage power station exhibits high flexibility in power regulation and frequency control and serves as one of the key approaches for new power systems to advance the “carbon peaking and carbon neutrality goals ” and drive the transformation of energy structure.First, the basic concepts of electrochemical energy storage power stations and their development status in China and abroad are summarized and analyzed.Then, the safety mechanism of electrochemical energy storage is analyzed based on typical fire safety accidents of global electrochemical energy storage power stations.The necessity of fire safety management is elaborated on from three dimensions, namely technology, safety, and economy, and the current progress in fire safety management of these electrochemical energy storage power stations is reviewed.Finally, the challenges in fire safety management during the construction of new power systems supported by grid-side electrochemical energy storage power stations and the key future development directions of fire safety management are discussed, aiming to provide references for research on the fire safety management of grid-side electrochemical energy storage power stations.

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Hybrid energy storage configuration method to satisfy peak regulation and primary frequency modulation functions of photovoltaic power stations
Xiulan PANG, Qi YANG, Xiaofeng LI, Xiaodi ZANG, and Zhongguan WANG

Date posted: 12-18-2025
DOI: https://doi.org/10.19781/j.issn.1673-9140.2025.05.016

Existing energy storage configuration methods for photovoltaic （PV） power stations often employ a single type of energy storage and typically overlook the influence of primary frequency modulation signals on the operational state of the storage system.This can lead to a mismatch between the configuration outcomes and actual operational requirements.To enable energy storage systems in PV power stations to simultaneously support peak regulation and frequency modulation, this paper introduces a hybrid energy storage configuration method designed to satisfy the dual functions of peak regulation and primary frequency modulation.Initially, the joint operational mode of the energy storage system and the PV power station is analyzed.Based on the assessment requirements for tracking and frequency modulation as stipulated in the two guidelines issued by National Energy Administration in 2020, a coordinated strategy for the hybrid energy storage system of the PV power station is proposed.Subsequently, a bi-level hybrid energy storage configuration model is developed, considering various operational scenarios including peak regulation, tracking assessment, and primary frequency modulation for PV power stations.Finally, the proposed configuration method is validated using real-world data from an integrated PV-storage experimental facility.The results indicate that the proposed configuration offers superior economic benefits and, when simulated, significantly improves the performance in peak regulation, tracking, and primary frequency modulation.

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Multi-time-scale rolling optimization and control strategy for hybrid energy storage based on empirical mode decomposition
Wenyuan ZHANG, Liping TAN, Zhiqiang XU, Qing CHEN, Shijie ZHANG, and Yushuang HE

Date posted: 12-18-2025
DOI: https://doi.org/10.19781/j.issn.1673-9140.2025.05.017

To effectively improve the new energy accommodation level of photovoltaic （PV） transformer districts and the tie-line power fluctuation suppression capability and address the problem that various energy storage systems cannot achieve optimal output from a global perspective due to the need for secondary correction in the “optimization-first and decomposition-later ” control approach, a multi-time-scale rolling optimization and control strategy for hybrid energy storage based on empirical mode decomposition （EMD） is proposed.Firstly, the EMD is used to decompose the net load power of transformer districts into high-frequency and low-frequency modal components, which are taken as the reference output powers of the supercapacitor and lithium-ion battery, respectively.Secondly, a multi-time-scale rolling optimization and control model for hybrid energy storage is designed.The long-time scale takes the optimal economic operation of transformer districts as the objective, while the short-time scale aims to minimize the tie-line power fluctuation rate.With the constraints of the regulation characteristics and operating status of different energy storage systems considered, the reference output powers of each energy storage system are rolling-optimized.This simplifies the optimization control steps, improves the control effect of hybrid energy storage, and realizes the optimal power allocation of hybrid energy storage with the safe operation of lithium-ion batteries considered.Finally, simulation results show that the proposed control strategy can avoid frequent and large-scale operations of lithium-ion battery energy storage, ensuring the safe and reliable operation of lithium-ion batteries.Under the same rated power and state of charge conditions, the proposed control strategy achieves a better suppression effect, which can effectively improve the economy and stability of the transformer district operation.

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Multi-control parameter optimization method for DC microgrids based on quadratic index
Jinyuan LIU, Tianjiao FENG, and Xiaorong ZHU

Date posted: 12-18-2025
DOI: https://doi.org/10.19781/j.issn.1673-9140.2025.05.018

In DC microgrids, there is interaction between different types of converters, which is easy to be affected by disturbance during operation, resulting in decreased power quality.Therefore, the stability of DC microgrids has become a key issue in microgrid research.In this paper, the small signal model of DC microgrid system including voltage source converter （VSC） and buck-boost DC-DC converter is derived, and the eigenvalues and participation factors of the system are calculated.The stability regions of key control parameters such as PI parameter, droop coefficient, and virtual inertia coefficient are compared with and without grid-connected converter.Then, according to the quadratic theory, the influence of different controller parameters on the system stability margin is studied.Finally, Monte Carlo algorithm is used to optimize the parameters of several key controllers globally.Simulation results show that the stability of the system with grid-connected converter is stronger.The optimized system has a smaller quadratic index, larger system damping, increased maximum power output of the energy storage, and improved stability margin.

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Optimal configuration of regional integrated energy systems considering energy demands across se miconductor industry chain
Bo LIU, Tao HUANG, Hui YAN, Rui LIANG, Yixiang CHEN, Xuequan XIAO, Fanlin MENG, and Shen CAO

Date posted: 12-18-2025
DOI: https://doi.org/10.19781/j.issn.1673-9140.2025.05.019

As the construction of new power systems advances, industrial energy demands grow diverse, with significant differences across upstream, midstream, and downstream industrial chain segments.Against this backdrop, there’s an urgent need to build integrated energy systems （IES） that satisfy the energy needs of whole-industry-chain clusters.This imposes higher demands on the optimal allocation and efficient operation of IES.To this end, the semiconductor industry is taken as an example, and a strategy is proposed for optimal allocation of regional integrated energy tailored to the semiconductor whole-industry-chain energy demands.First, according to the energy consumption characteristics of each production segment, the semiconductor industry chain clusters are divided into multi-regional integrated energy systems with power interconnection.Subsequently, the economic benefits and equipment capacities of each region are incorporated into a two-layer planning model, which is solved hierarchically by a dynamic adaptive particle swarm optimization algorithm combined with the Gurobi solver.Finally, case studies validate the effectiveness of the proposed strategy in enhancing the economic benefits of the systems and achieving efficient energy allocation.

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Optimization scheduling strategy of integrated energy system considering demand response and carbon trading
Haifeng ZHANG, Xiaohua LI, and Xinghua ZHOU

Date posted: 12-18-2025
DOI: https://doi.org/10.19781/j.issn.1673-9140.2025.05.020

In response to output uncertainty and strong volatility of renewable energy such as wind power and photovoltaics in integrated energy systems, an optimization scheduling strategy of the integrated energy system considering demand response and carbon trading is proposed.First, the scenario generation and rapid antecedent elimination technology of Latin hypercube sampling are used to deal with the uncertainty of wind and solar power.Then, the demand response mechanism and carbon trading mechanism are combined to consider the system carbon emissions while satisfying the supply and demand balance of the energy system.A low-carbon optimization scheduling model for the integrated energy system is constructed to minimize the system operating costs and carbon emissions.Finally, comparative analysis of different scenarios shows that the scheduling method effectively utilizes the adjustable resources in the energy system, further improves the operating efficiency of the system and consumption capacity of renewable energy, and achieves the low-carbon economic scheduling goal of the energy system.

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A single-stage matrix-type solid-state transformer with reduced switching tubes
Siwei LIN and Zhike XU

Date posted: 12-18-2025
DOI: https://doi.org/10.19781/j.issn.1673-9140.2025.05.021

This paper presents a single-stage matrix-type solid-state transformer （SM-SST） with reduced switching tubes.In the proposed topology, the power-frequency full bridge shares filter capacitors with high-frequency （HF） half-bridges, which effectively reduces the number of switching tubes and capacitors.The adoption of electrolytic capacitorless matrix-type topology enhances the system ’s potential reliability and power density, achieves instantaneous power balance between the source and load, eliminates ripple power with double grid frequency, and enables inherent power factor correction （PFC） without the need for a current control loop.Additionally, this paper analyzes the zero voltage switching （ZVS） characteristics under time-varying DC bus voltages.As a result, the proposed SM-SST offers advantages of fewer components, lower power losses, and a higher power density.Finally, a 1 kW experimental prototype is constructed and tested to validate the accuracy and feasibility of the proposed method.

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Precise feedback decoupling control of a three-level Buck converter based on a pre-filter
Xin FAN, Jiarong WU, Lin YANG, and Weilin WU

Date posted: 12-18-2025
DOI: https://doi.org/10.19781/j.issn.1673-9140.2025.05.022

To improve the stability performance of a three-level Buck converter, a precise feedback decoupling control strategy based on a pre-filter is proposed.The mathematical model of the three-level Buck converter is established, and the reversibility analysis of the model is carried out based on the inverse system theory.The original model is linearly decoupled into two pseudolinear subsystems.The proportional-integral controller and the optimal controller are designed for the two subsystems, respectively to improve the performance of the system and suppress the influence of external disturbances on the system.Then, the pre-filter is designed to eliminate the adverse effects of the closed-loop zero point.Simulation and experimental results show that compared with the existing control methods, the proposed control strategy has faster response speed, better stability, and stronger robustness.

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Model predictive control method for degaussing power supply current in induced magnetic field of ship
Xiaohui YANG, Wentao HUANG, Huanhong YANG, and Moduo YU

Date posted: 12-18-2025
DOI: https://doi.org/10.19781/j.issn.1673-9140.2025.05.023

A ship generates a compensating magnetic field by supplying power to multiple sets of degaussing coils, and when a single degaussing coil fails, the remaining degaussing coil current needs to be adjusted quickly.To address the difficulty of degaussing power supply to maintain the magnetic field quickly and accurately when the coils fail, this paper proposes a model predictive control method for Buck converter-type degaussing power supply current, which realizes the stable and fast control of degaussing current.By analyzing the working principles of the front and rear two-stage converters, this study develops a two-stage multi-output Buck converter state-space averaging model, based on which the model predictive controller of the degaussing power supply is designed.Using Matlab/Simulink simulation model, the study verifies the effectiveness of the proposed control method and carries out numerical simulation on the ship’s resultant magnetic field.The simulation results show that the proposed method can restore the magnetic field to a safe range in the shortest possible time.

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Simultaneous wireless power and information transmission technology based on 16QAM
Jian ZHANG, Jie ZOU, Lei WANG, Taotao ZHENG, and Jun ZHOU

Date posted: 12-18-2025
DOI: https://doi.org/10.19781/j.issn.1673-9140.2025.05.024

A simultaneous wireless power and information transmission （SWPIT） technology based on 16-quadrature amplitude modulation （16QAM） is proposed to achieve efficient and synchronized transmission of both power and information over a single transmission channel.The technology integrates a wireless power transfer module, a signal generation module, a transmission control module, and a signal acquisition and demodulation module to work in concert.It utilizes phase-shift control for stable transmission and soft switching operation during independent power transmission.By combining the 16QAM and the sinusoidal pulse width modulation （SPWM） technology during synchronized transmission of power and information, it also resists channel interference and ensures the accuracy and reliability of information transmission.The system can automatically switch between two transmission modes according to the transmission requirements, and its performance in practical applications is validated by establishing an experimental platform.It demonstrates low error rates and efficient and stable power and information transmission capabilities, thereby proving the feasibility and practicality of the proposed system.

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A distributed trading connection model between electricity spot market and green electricity capacity market based o n perfect equilibrium of subgame
Guozhong LUO, Qilin CHENG, Ming ZHU, Xiaolu LI, Gangyi ZHU, Shiyi LIU, Jun LI, Yuguo CHEN, and Jian ZHANG

Date posted: 12-18-2025
DOI: https://doi.org/10.19781/j.issn.1673-9140.2025.05.025

Under the guidance of the carbo n peaking and car bon neutrality policy, diversified markets such as the electricity spot market and the green electricity market coexist.In response to the mismatch in trading connections caused by the time difference between the green electricity capacity market and the electricity spot market, a distributed trading connection model between the two markets based on the perfect equilibrium of the subgame is proposed.Firstly, the cost and benefit functions of the electricity spot market are proposed, and those of the green electricity capacity market are also provided.Secondly, a trading connection model between the electricity spot market and the green electricity capacity market is established, and a comprehensive income model is provided.Thirdly, a model for perfect equilibrium of the subgame is proposed for the electricity spot market and green electricity capacity market.On this basis, an improved distributed consensus algorithm is proposed and solved.Finally, the proposed model is validated by IEEE 14 node system, demonstrating its optimization effect on both markets.

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Robust stochastic bidding strategy for combined wind farm and energy storage system participating in spot markets with multiple uncertain factors considered
Yang WU, Yuan LENG, Xiumin HUANG, Zhilin LU, Shuangquan LIU, Ziyang LIANG, and Mingbo LIU

Date posted: 12-18-2025
DOI: https://doi.org/10.19781/j.issn.1673-9140.2025.05.026

Wind power enterprises struggle to guarantee their revenue in the electricity spot market due to the reverse peak regulation characteristic and the uncertainty of wind power.To address these issues, the advantages of compressed air energy storage （CAES） including large capacity, long service life, low cost, and high efficiency are utilized, and a biddin g strategy for the combined wind farm and CAES to jointly participate in the day-ahead, intraday, and real-time markets is proposed.With the goal of maximizing the system ’s revenue in the spot market, typical scenarios are used to describe the uncertainty of wind power output and intraday electricity price, and an uncertainty set is used to describe the uncertainty of day-ahead electricity price.With the operational constraints of wind power and energy storage considered, a risk-averse robust stochastic bidding model is established, and the column and constraint generation （C&CG） algorithm is adopted to solve it.A case study is carried out on a combined wind farm and CAES system to verify that the proposed method can determine a reasonable bidding strategy to guarantee the revenue of the wind storage system.

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Optimization methods of shared energy storage in rural multiple transformer districts based on credibility incentive
Yanwei ZHANG, Xiangbing JIANG, Zhen LI, and Bo TANG

Date posted: 12-18-2025
DOI: https://doi.org/10.19781/j.issn.1673-9140.2025.05.027

In response to the heavy overload and reverse power of transformers caused by the high proportion of distributed power sources and new loads connected to rural power distribution systems, an optimization method of shared energy storage in rural multiple transformer districts is proposed based on credibility incentive.First, a power grid-transformer district load aggregator （transformer district load aggregator, TDLA）-user system operating framework is established.An effective demand response strategy is formulated based on credibility incentives and response volume metrics are introduced, allowing TDLA to interact with users who have a large number of flexible resources, guide users to change their own electricity consumption strategies, and optimize the source-charge relationship.Secondly, the source-load differences between multiple transformer districts and the resource sharing of shared energy storage as adjustment means are fully utilized to establish a multiple TDLA-shared energy storage two-layer optimization model.The upper model takes the lowest cost of the multiple TDLA as the goal, while the lower-layer model aims to minimize the amount of electricity sent back to the power grid from multiple transformer districts.Finally, through an actual case of a rural distribution network in Shanxi, it turns out that the TDLA operating costs can be reduced by the application of optimization method of shared energy storage in rural multiple transformer districts based on credibility incentive, with the decreased power backflow from the station to the power grid as well as the lower load rate and reverse load rate of the transformer districts.

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Study on grounding test of induced voltage and its protection distance in power transmission and distribution corridors
Jiong CHEN, Ziyi QIN, Aiqing MA, Maoxin REN, and Fan YI

Date posted: 12-18-2025
DOI: https://doi.org/10.19781/j.issn.1673-9140.2025.05.028

The extra-high voltage and ultra-high voltage transmission lines pose significant induced voltage hazards to the adjacent distribution lines beneath them, creating difficulties for distribution maintenance work.Installing grounding wires on the lines is one of the most effective protective measures against induced voltage, but there is a lack of experimental simulations and quantitative guidance that can support practical engineering.Based on the principle of induced voltage, experiments are designed to verify the effectiveness and distance limitation of induced voltage grounding protection during distribution maintenance.The influence of voltage level, number of circuits, and grounding interval distance on induced voltage is explored, and a simplified calculation formula for induced voltage under distribution line single-side grounding conditions is derived；the safe grounding interval distance under various typical operating conditions is calculated, and the selection of protective equipment is refined after the distribution line is grounded.The results show that the measured induced voltage of the ungrounded conductor under the 220 kV double-circuit line is approximately 963.7 V, and it decreases by 99.69% after grounding, showing a significant effect.The grounding protection for distribution lines has a distance limitation, and the induced voltage increases as the line voltage level, number of circuits, and grounding interval distance increase.After grounding the distribution line under various operating conditions, the induced voltage is reduced by 92.77%~97.71%.The safe grounding interval distance for the distribution line under the ultra-high voltage line is only 0.094 km, and there are five risk levels, for which different protective equipment must be adopted to address.The results obtained can provide a reference for the safety work in distribution line maintenance.

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Temperature rise and failure characteristics of zinc oxide resistor for arrester considering pulse current waveform
Yutang MA, Jun CAO, Lu QU, Hao GENG, Jun SHI, and Ziping LIU

Date posted: 12-18-2025
DOI: https://doi.org/10.19781/j.issn.1673-9140.2025.05.029

Multiple lightning strikes can cause thermal failure of arresters under impact, posing a threat to the safe operation of the power system.This article establishes an electric-thermal instantaneous coupling model for zinc oxide resistors under multiple pulse current waveforms, proposes an integration criterion for equivalent current energy, compares the thermal characteristics of zinc oxide resistors under multiple lightning pulse waveforms, continuous pulse current waveforms, and equivalent current waveforms, and analyzes the influence of pulse current waveforms on the thermal characteristics, degradation forms, and failure mechanisms of zinc oxide resistors based on the simulation test results of impact damage of zinc oxide resistors under continuous pulse currents of different waveforms.The impact time interval influences the thermal characteristics of zinc oxide resistors.The longer the pulse time interval, the more obvious the saturation trend of temperature rise with the increase of pulse frequency.Under the same waveform energy integration conditions, the pulse current waveform has little effect on the thermal characteristics of zinc oxide resistors.However, the pulse current waveform influences the failure mode of the zinc oxide resistor, with insulation perforation being the main mode at 8/20 μs, insulation burning being the main mode at 120 μs sine half wave, and insulation layer carbonization being the main mode at 210 μs sine half wave.

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Impact of complex operating conditions caused by superposition of photovoltaic access and system short-circuit on distribution network lightning arrester operation
Jin BAI, Xiu ZHOU, Xin YANG, Tian TIAN, and Rui YIN

Date posted: 12-18-2025
DOI: https://doi.org/10.19781/j.issn.1673-9140.2025.05.030

In recent years, a large number of photovoltaic power sources have been connected to the distribution network, and the line voltage fluctuations caused thereby have become a research hotspot.However, at present, there is insufficient understanding of the complex operating conditions formed by the superposition of overvoltage generated by short-circuit faults in the distribution network and system voltage fluctuations caused by photovoltaic access, as well as a lack of knowledge about the fault mechanisms of distribution network lightning arresters and other equipment under such operating conditions.To solve the above problems, a simulation calculation model for substation overvoltage with photovoltaic access is established.Under the condition of a superimposed system short-circuit overvoltage, the impact of small system disturbances on the voltage at the photovoltaic grid-connected point during photovoltaic access is analyzed through simulation.It is found that after photovoltaic access, under the same fault conditions, the overvoltage amplitude at the grid-connected point is larger, and the duration is longer.By taking actual fault cases as examples, it is found that if the voltage amplitude increases by 23%, the duration will be extended by 3.5 times.The voltage waveform under complex operating conditions is applied to the constructed calculation module for the current-carrying capacity of the lightning arrester, and its impact on the thermal charge transfer value of the lightning arrester is analyzed.Simulation results under typical case conditions show that before and after photovoltaic access, under the condition that the line-to-line short-circuit fault triggers the operation of the lightning arrester, the thermal charge transfer value increases from 0.65 C to 1.85 C, and the absorbed energy increases by 1.8 times, which is sufficient to cause thermal collapse of the lightning arrester.Relevant research has achieved a deeper understanding of the complex operating conditions of distribution network lightning arresters with a large number of photovoltaic accesses, and provides a method for guiding the selection of distribution network lightning arresters.