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Research on optimization of electric vehicle charging scheduling in rainy season based on peak valley difference electricity price model
Zhikun LUO, Wenhao YE, Yaohong CHEN, Qin YAN, Shusheng WU, and Jinxin WANG

Date posted: 10-22-2025
DOI: https://doi.org/10.19781/j.issn.1673-9140.2025.04.011

To address the issues of increased energy consumption of electric vehicles，grid load，and peak valley difference caused by high humidity and temperature in the rainy season in Southern China，a charging price model based on peak valley difference is proposed to stimulate electric vehicles to participate in demand response，so as to stabilize the peak valley difference of grid load and improve the economic benefits of electric vehicle users.Firstly，the Monte Carlo simulation is used to analyze and predict the disordered charging load of electric vehicles，considering factors such as high temperature and humidity during the rainy season in Southern China.Then，a peak-valley differential charging price model is built to minimize the peak valley difference of the power grid and the user charging cost.Lastly，simulation analysis is conducted on the model using the MATLAB application.The research shows that the proposed model considering the high humidity and temperature of the rainy season in Southern China is more accurate.The model can reduce the peak valley difference rate，improve the economic benefits of users，and realize the smoothing and optimization of grid load.The research provides a reference for a new electric vehicle charging scheduling.

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Summary of research on electricity theft behavior detection methods
Yu XIAO, Zhi YE, Rui HUANG, Mouhai LIU, Rui XIA, and Yunpeng GAO

Date posted: 11-6-2023
DOI: https://doi.org/10.19781/j.issn.1673-9140.2023.04.001

The non‑technical losses caused by electricity theft in the power system have always been a pressing issue for power grid companies to urgently address. With the deployment of a large number of smart meters in the power grid, the use of user‑side data collected by the power metering automation system to accurately detect electricity theft has attracted widespread attention from researchers and power grid companies. Firstly, the basic classification of users' electricity stealing behavior, evaluation indicators and existing electricity theft detection data sets are introduced. Then, from the four aspects of grid state analysis, machine learning, game theory and hardware, the existing detection methods of electricity theft behavior are comprehensively sorted, analyzed and compared, and the basic ideas, advantages and disadvantages of each method are summarized. Finally, the current challenges in the field of electricity theft behavior detection are deeply analyzed, and a prospective outlook on the focus of future research work is provided.

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Method for anomaly detection of converter valve voiceprints based on improved denoising auto-encoder
Yisheng YU, Zhihong WANG, Yunya ZHOU, Zhanfan ZHOU, Yu YAN, Yu YU, and Mingzhu TANG

Date posted: 2-1-2026
DOI: https://doi.org/10.19781/j.issn.1673-9140.2025.06.017

The converter valve, as a key equipment in high-voltage direct current transmission converter stations, may experience an abnormal state when operated for a long time. To address the problem that non-intrinsic background noise in the valve hall may cause voiceprint anomalies and unstable anti-noise performance of the converter valve, an anomaly detection method for the converter valve based on voiceprint signal filter banks (Fbank) features and an improved denoising auto-encoder (IDAE) is proposed. Firstly, the voiceprint data generated during the operation of the converter valve is collected; the Fbank features of the voiceprint data are extracted; the samples containing temporal information through sliding window (SW) processing are obtained. Then, a denoising auto-encoder (DAE) based on environmental noise and dual channels is constructed to train normal samples, and multiple feature thresholds are calculated through fused directional distance (FDD) reconstruction error. Finally, speech, white noise, and industrial background noise with different signal-to-noise ratios are added to the test data for comprehensive performance evaluation. The experimental results show that compared with other anomaly detection models, the proposed method has better performance and stronger noise resistance.

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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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Identification of key links in integrated energy system based on power flow and complex network theory
Siqi WANG, Zhixian LIANG, Zhijie WANG, and Hong WANG

Date posted: 7-25-2024
DOI: https://doi.org/10.19781/j.issn.1673-9140.2024.03.026

The identification of key links in a comprehensive energy system is of great significance for the research and improvement of system vulnerability. Aiming at the problem that the traditional reductionism method can not explain the system level and the influence of energy flow is not considered in the analysis of complex network, a key link identification method of the IES based on power flow and complex network structure is proposed. Firstly, a comprehensive energy complex network model is established based on power flow, and the mathematical model parameters and power flow results of the IES are introduced into the modeling of complex network to make the model more suitable for realistic operating conditions. Secondly, based on the power flow calculation results and complex network parameters, two evaluation indicators, i.e. node energy degree and energy edge intermediate, are proposed to improve the identification accuracy of key links. Finally, based on the established model, the key links are destroyed and the changes in network efficiency are observed. Compared with other attack modes, the feasibility of the proposed method is verified.

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Robust control of output voltage of DAB converter by super -twisted sliding mode method
Jianlin LI, Laixin GUO, and Penghui HAN

Date posted: 10-22-2025
DOI: https://doi.org/10.19781/j.issn.1673-9140.2025.04.021

The traditional sliding mode control （SMC） used for the isolated dual active bridge （DAB） converter is robust and can improve the dynamic performance of nonlinear systems.To address the disadvantages of buffeting and decreasing tracking performance，a super-twisted sliding mode control （ST-SMC） method is proposed to enhance the output voltage regulation ability and robust control ability of the converter.The ST-SMC method is adopted，and the technical advantages of the sliding mode controller are combined to effectively eliminate the buffeting problem.During the design of the sliding mode controller，the average mathematical model of the DAB converter under single-phase shift control is fully considered，and the design process is effectively simplified.The stability and robustness of the direct current （DC） output voltage of the DAB converter are improved effectively，and accurate reference voltage tracking is realized.In addition，the method provides robust control over parametric uncertainties，and the steady-state output voltage of the DC converter contains fewer ripple components than traditional SMC and PI controllers.Finally，based on the TMS 320F28335 digital controller，a 1kW DAB converter prototype is installed to verify the effectiveness of this new control method.

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Detective effect of oscillation on different defects of cable from the perspective of materials and electric field
Jihe YUAN, Yang YANG, Xi ZHANG, Huayong HUANG, Xianjin WANG, and Kai ZHOU

Date posted: 9-4-2020
DOI: https://doi.org/10.19781/j.issn.16739140.2020.04.006

The effect of the oscillating wave on the interfacial and internal defects of cable from the perspective of the electric field is studied in order to understand the test results of the oscillating wave voltage method for different defects in cables. Firstly, an oscillating wave test platform is set up to partial discharge tests the artificial defective models including longitudinal knife defects and external semiconductor lap defects. Then, the excitation characteristics of oscillation wave are analyzed primarily by PDIV and PRPD. Furthermore, the electric field distribution of cables with defects are simulated by utilizing a finite element simulation software in threedimension. Artificial defects with different sizes are fabricated to represent the diversity of the defect site and the characteristics of defective discharges are explained by the electric field distortion at the defects. Experimental and simulation results show that: it is hard to detect the internal defects due to the filling of hard grease by using the oscillation wave voltage method, whereas interfacial defects of poor connection of outer semiconductor has better characterization results.

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A review of vehicle-grid interaction with introduction of virtual power plants
Yanxia WANG, Yuchen WANG, and Shaojun GAN

Date posted: 4-30-2026
DOI: https://doi.org/10.19781/j.issn.1673-9140.2026.02.002

The advent of virtual power plants (VPPs) promotes the development of the interaction between electric vehicles (EVs) and the power grid, and plays an important role in promoting the load balance of urban power grids. By systematically reviewing the relevant literature on EVs, integrated photovoltaic storage and charging stations, and VPPs and their aggregators, this paper analyzes the vehicle-grid interactions with the introduction of VPPs, summarizes the commonly used EV load forecasting methods, and describes the siting and capacity planning model of integrated photovoltaic storage and charging stations. Further, it summarizes the game relationship among the grid layer, the VPP and its aggregator, and the user layer in the process of vehicle-grid interaction. Finally, it summarizes the existing studies, and provides an outlook on the future development of vehicle-grid interaction by combining with the case studies of the VPPs of different countries.

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Variable parameter VSG control based on adaptive exponential function
Lina WANG, Yichao WANG, Liping TAN, Zhiqiang XU, Wenjun LIU, and Haotian LIU

Date posted: 9-19-2023
DOI: https://doi.org/10.19781/j.issn.1673-9140.2023.03.013

In recent years, with the increasing electronization of the power grid, the overall inertia of the grid has decreased. As a result, the technology of virtual synchronous generator (VSG) has emerged and rapidly developed. The core idea is to mimic the electrical and mechanical characteristics of synchronous generators used in traditional power systems in order to enhance the rotational inertia of high‑proportion distributed energy systems. However, the existing control strategies for VSG have fixed control parameters or simple continuous variations, which may lead to power oscillations in the system when subjected to small disturbances. In order to adjust the virtual inertia and damping coefficient more flexibly, a variable‑parameter VSG adaptive control strategy based on piecewise exponential functions is proposed after a detailed analysis of VSG. The variation of virtual inertia and rotational damping with grid frequency follows an exponential function trajectory, aiming to reduce grid fluctuations. Additionally, when the disturbance rate is low, the parameter changes are small to avoid causing system oscillations. Finally, the parameters of the main circuit and the VSG control part are designed, and simulation results show that the strategy can effectively improve the stability of the inverter operation.

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A review of demand response capability assessment based on CPSS perspective
Kairui ZHANG, Hao MING, and Ciwei GAO

Date posted: 4-22-2024
DOI: https://doi.org/10.19781/j.issn.1673-9140.2024.01.003

The combination of cyber-physical-social systems and demand response assessment is reviewed. First, the history and framework of cyber-physical systems are analyzed. Then, summaries are provided for the existing research on demand response, including the significance, classification, and evaluation methods of demand response potential assessment, as well as the data sources for demand response capability assessment, including questionnaire surveys and operational data collection. In terms of the combination of cyber-physical-social systems and demand response, the physical domain, information domain and social domain foundation of demand response are analyzed respectively, and the corresponding modeling methods and research contents are introduced. Finally, prospects are provided for market assessment mechanisms, rapid simulation and modeling technologies, and demand response management under integrated energy systems.