23 August 2026, Volume 45 Issue 8
    

  • Select all
    |
    Treatise and Report
  • Convergence improvement method of finite element calculation based on vector hysteresis model in rotating magnetization
    FU Xiaotong, XU Xiaoyu, YAN Shuai, ZHOU Yaxing, REN Zhuoxiang
    Advanced Technology of Electrical Engineering and Energy. 2026, 45(8): 1-9. https://doi.org/10.12067/ATEEE2512005
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    The T-shaped region of rotating motors or three-phase transformers is often under rotating magnetization, so it is necessary to use a vector hysteresis model to describe the hysteresis characteristics of the material. Finite element simulation using the vector hysteresis model allows for accurate calculation of field distribution, voltage and current variation, and core loss of equipment such as motors and transformers. However, the complexity of the vector hysteresis model may prevent the convergence of the calculation process. In order to improve the convergence and stability, three methods are proposed in this paper to deal with the non-convergence problem in different magnetization stages. The first method is to use sub-time steps to construct excitation increasing stages when the initial excitation is large. The second method is to use a local ladder numerical method to deal with the differential magnetic reluctivity near the zero point of magnetic induction intensity. The third is to ignore the hysteresis effect under a specific small magnetic induction intensity and use linearization to deal with the differential magnetic reluctivity. Taking the TEAM 32 problem as an example, the three convergence improvement methods are combined to realize the finite element analysis with the vector hysteresis model. The calculated results are consistent with the measured data, which verifies the reliability of the method.
  • Simulation of magnetic properties of soft magnetic materials using dynamic Jiles-Atherton hysteresis model and time-periodic finite element method
    CHEN Bin, WANG Yingyi, WANG Shuaibing, LIU Yang
    Advanced Technology of Electrical Engineering and Energy. 2026, 45(8): 10-20. https://doi.org/10.12067/ATEEE2603009
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    To address the limitations of existing time-periodic finite element methods—which neglect dynamic hysteresis effects when analyzing the magnetic properties of soft magnetic materials and are prone to iterative instability when complex hysteresis models are introduced—this paper proposes an improved time-periodic finite element algorithm that incorporates a dynamic Jiles-Atherton hysteresis model. First, based on the theory of loss separation, an inverse Jiles-Atherton hysteresis model accounting for dynamic hysteresis effects was constructed, and the frequency-dependent evolution of the model parameters was determined. Second, to enhance the robustness of nonlinear iteration, a tuning factor was introduced in the selection of the magnetic permeability. By monitoring the number of peaks in the magnetic flux density waveform, the tuning factor was dynamically optimized, thereby establishing a stable, fixed-point two-dimensional field-circuit coupled finite element model. Finally, simulations were conducted and compared with experiments using a nanocrystalline magnetic ring as the test object. The results indicate that the proposed method can accurately predict magnetic characteristics under various operating conditions, with the normalized root-mean-square error of the excitation current maintained within 3.09% and the maximum relative error in core loss calculation at 7.27%, thereby validating the effectiveness and accuracy of the method presented in this paper.
  • Quantitative analysis method for spatial acoustic strain of partial discharge in power equipment
    LYU Anqiang, LI Xinpeng, KONG Yan, ZOU Tianxiang
    Advanced Technology of Electrical Engineering and Energy. 2026, 45(8): 21-30. https://doi.org/10.12067/ATEEE2507016
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Currently, when using electronic ultrasonic sensors to monitor the partial discharge of power equipment, the minimum detectable strain value has not yet been established through experimental means as a quantitative standard. To conduct a quantitative study on the minimum detectable strain value of the electronic ultrasonic sensor, a quantitative analysis method is proposed for the spatial acoustic field strain of power equipment partial discharge. Firstly, a needle plate discharge test platform is set up, and the ultrasonic signals in the space are measured using the electronic ultrasonic sensor. The speed of the diaphragm is calculated through the sensitivity coefficient. Secondly, the same discharge model is established in the finite element simulation software, and the equivalent speed of the spatial acoustic field is used to explore the amplitude range of the partial discharge ultrasonic point sound source corresponding to the experiment, thereby establishing a function relationship between the partial discharge quantity and the amplitude of the partial discharge ultrasonic point sound source. Finally, based on this function relationship, the quantitative analysis of the acoustic field strain of the partial discharge sound field is completed. The results show that the actual amplitude of the partial discharge ultrasonic point sound source, which is usually set as 1 in existing literature, is actually at the order of 10-7, and this amplitude has a linear relationship with the partial discharge quantity. The acoustic field strain of the partial discharge can be calculated in the simulation based on this linear relationship, and thus the sensitivity parameters that the electronic ultrasonic sensor should meet can be obtained.
  • Parameter degradation model and device simulation model for SiC MOSFETs during aging process
    LIU Qingsong, SUN Pengju, MA Xing
    Advanced Technology of Electrical Engineering and Energy. 2026, 45(8): 31-43. https://doi.org/10.12067/ATEEE2504030
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    SiC MOSFET devices face chip aging issues caused by gate oxide degradation, with their electrical characteristics evolving during the aging process, which critically impacts key parameters such as power loss and junction temperature. To evaluate the operational performance of SiC MOSFETs and associated power electronics systems during aging, it is essential to clarify the device aging mechanisms and develop simulation models that characterize device behavior across various aging states. This paper investigates the threshold voltage degradation mechanisms of SiC MOSFETs under AC gate stress and establishes a corresponding characterization model. A device simulation model is proposed to capture the impact of threshold voltage variations on electrical characteristics. The effects of gate voltage amplitude, frequency, and temperature on threshold voltage drift are systematically analyzed through AC gate bias accelerated aging tests, enabling the development of a degradation model for threshold voltage. Key physical processes governing channel current are modeled, with threshold voltage serving as the aging indicator, to derive a channel current model reflecting the influence of aging on static characteristics. This model is integrated with nonlinear capacitance models to construct a comprehensive device simulation framework. Finally, the accuracy of the proposed model in characterizing static properties across aging states is validated through simulation-measurement comparisons. The model’s capability to simulate switching behavior before and after aging is further verified via double-pulse tests.
  • Single-phase dual T-type three-level inverter and its control method
    YUAN Yisheng, ZENG Ruijin, CAO Hui, YI Jiali
    Advanced Technology of Electrical Engineering and Energy. 2026, 45(8): 44-52. https://doi.org/10.12067/ATEEE2507025
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    The traditional T-type three-level inverter is widely used in the field of new energy generation due to their high efficiency and low leakage current. However, their limited input voltage range fails to meet the requirements of certain renewable energy applications. In this paper, a single-phase dual T-type three-level inverter is proposed, which can adapt to a wider range of input voltage fluctuations. Three modulation methods are proposed for this inverter: high-gain three-level modulation, low-gain three-level modulation and hybrid modulation. Among them, high-gain three-level modulation is suitable for low-voltage input, which can reduce the input voltage range to 1/2 of the traditional single-phase T-type three-level inverter; low-gain three-level modulation is suitable for high-voltage input, and by controlling the two capacitors to work in high-frequency rotation, it can realize the balance of mid-point potentials and reduce the inductor current ripple. And the hybrid modulation is a combination of high-gain three-level modulation and low-gain three-level modulation, which has the advantages of wide range, high efficiency and good waveform quality. The working principle of the single-phase double T-type inverter is explained, its mathematical model is derived, and a three-loop control scheme including an outer loop for output voltage, an inner loop for inductor current, and a midpoint voltage balance loop is proposed. The experimental results of the prototype confirm the feasibility of the circuit and its control method.
  • Large wind turbine tower vibration reduction control based on improved LADRC
    JIA Chengzhen, LIU Yushan, WANG Lingmei, CHEN Zhengkun, ZHOU Zhipeng, MENG Enlong, HUANG Hu, CHEN Liming
    Advanced Technology of Electrical Engineering and Energy. 2026, 45(8): 53-63. https://doi.org/10.12067/ATEEE2507034
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    To address the issue of tower vibration and nonlinear dynamics during large-scale wind turbine operation, this paper develops a damping control algorithm for the tower based on a resonant compensation linear active disturbance rejection controller. The research proceeds as follows: Firstly, the force and motion equations of the tower are examined, and the dynamic characteristics of tower vibration, along with key factors influencing these dynamics, are identified. Secondly, by designing pitch damping control algorithms using a second-order linear active disturbance rejection controller framework, the impact of the proposed control strategy on the system’s damping ratio is analyzed, and corresponding control parameters are determined to mitigate front-rear and left-right vibrations of the tower. Finally, taking the NREL 5 MW wind turbine as a case study, verification results demonstrate that the proposed method can effectively attenuate tower vibrations and load fluctuations, and enhance the control algorithm’s robustness and disturbance rejection capabilities.
  • Characteristic analysis of internal pipeline evaporative cooling system for vertical rotors
    LI Ruiwei, ZHAO Sheng, CHEN Jinxiu, RUAN Lin
    Advanced Technology of Electrical Engineering and Energy. 2026, 45(8): 64-72. https://doi.org/10.12067/ATEEE2509030
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Currently, hydropower units are developing towards higher single-machine capacity and higher rotational speeds, which has led to increasing difficulties in cooling the vertical motor rotors, creating an urgent demand for efficient rotor cooling technologies. This paper takes an operational hydropower unit as the research object to explore the feasibility and cooling effect of the internal pipeline evaporative cooling system. Firstly, a calculation model for rotor ventilation and heat dissipation under the existing air cooling method was established. Through fluid-solid conjugate heat transfer simulation analysis, the temperature distribution characteristics of the rotor excitation windings under air cooling were obtained, and the accuracy of the simulation method was verified by comparing with the actual measured data of the unit. Secondly, based on the air cooling configuration, a scheme of self-circulating internal pipeline evaporative cooling system for the rotor were designed. Combined with two-phase flow and heat transfer simulations, the circulation and heat transfer principle and technical feasibility of the rotor evaporative cooling system were analyzed. It was shown that the introduction of the evaporative cooling system can reduce the temperature of the excitation windings, improve the uniformity of temperature distribution, and eliminate local hot spots. The proposed cooling scheme provides feasible ideas and design references for the application of internal pipeline evaporative cooling technology in the field of vertical rotor cooling.
  • Temperature holding of drilling type in-situ pyrolysis of tar-rich coal with high-frequency induction heating
    SONG Mingyan, LIU Yibin, DONG Shuai, ZHU Lei, YU Lianchao, LIANG Deliang, XUE Yanting, LIANG Yang, WEN Qidong
    Advanced Technology of Electrical Engineering and Energy. 2026, 45(8): 73-81. https://doi.org/10.12067/ATEEE2502039
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    The temperature control scheme based on the high-frequency induction heating is proposed for the production wells of drilling type in-situ pyrolysis of tar-rich coal. The key of this scheme is to set 4 temperature control wells around each production well, and the heating device in each of the temperature control well is composed of multiple heating units in parallel. The heating unit includes high-frequency induction heating circuit, sealing heat-insulation device and start-stop control strategy. The heating circuit consists of the step-down transformer, three-phase uncontrolled rectifier, high-frequency inverter, and heating coil. The sealing heat-insulation device consists of multi-stage sealed chambers, in which the high-speed circulating nitrogen is loaded to bring the heat generated by the element to the ground cooling system, so as to maintain the low temperature in the sealed chamber. Based on the characteristics of the large-time constant of the temperature control system, a centralized start-stop control strategy based on temperature feedback of the producing well is proposed, and the simulation analyses verify the feasibility of the design scheme.
  • Improved two-stage load curve clustering method based on trend decomposition and enhanced K-Shape algorithm
    WANG Yihao, XIE Chao, PENG Shasha
    Advanced Technology of Electrical Engineering and Energy. 2026, 45(8): 82-91. https://doi.org/10.12067/ATEEE2507010\
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Existing load curve clustering methods frequently fail to adequately capture the diurnal fluctuations and intraday lag effects present in power load data, leading to clusters with limited accuracy and interpretability. To overcome these limitations, this paper proposes a two-stage clustering approach integrating the STL (seasonal-trend decomposition using loess) algorithm with an enhanced K-Shape method. Initially, the STL algorithm is applied to decompose the load data and remove the trend component, resulting in a detrended sequence. This sequence then undergoes a two-stage clustering process. In the first stage, the K-means++ algorithm is employed, where the optimal number of clusters is determined using the elbow method. The second stage involves an improved K-Shape procedure, incorporating unbiased estimators and coefficient normalization with compensation, yielding unbiased normalized coefficients. This enhancement facilitates the extraction of the optimal displacement partition (ODP) and enables the identification of cluster centroids through minimized distance measures. Experiments conducted on real-world power load data demonstrate that the proposed method outperforms the STL-K-means++ baseline, improving the SIL index by 10.07% to 48.99% and reducing the DBI index by 6.44% to 22.24%.
  • Investigation on evaluation method of discharge severity in oil-paper insulation based on total energy of decomposed gases
    based on total energy of decomposed gasesDAI Jingqi, JIAO Zaibin, DONG Ming, ZHENG Lu, LIU Xinrong, HU Yizhuo, ZHAO Yu, CHEN Ji
    Advanced Technology of Electrical Engineering and Energy. 2026, 45(8): 92-102. https://doi.org/10.12067/ATEEE2503013
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Dissolved gas analysis (DGA) is an essential diagnostic method for detecting internal faults in oil-paper insulated power equipment. However, the current DGA methods and criteria for ester-based insulating oils suffer from issues such as insufficient accuracy, poor applicability, and limited interpretability. In this study, simulation experiments were conducted on partial discharge, low-energy discharge, and high-energy discharge for mineral oil and three typical ester-based insulating oils. The concentrations of dissolved gases in the oils were measured, and fault identification and validation were performed using existing diagnostic methods. Additionally, the relationship between the weighted energy of decomposition gases and discharge energy was analyzed. The results indicate that the weighted energy of decomposition gases exhibits a significant advantage in distinguishing between low-energy and high-energy discharges, demonstrating high consistency across different types of insulating oils. Furthermore, the evaluation method based on the total weighted energy of decomposition gases for assessing the severity of discharge in oil-paper insulation proves to be highly feasible.
    • New Technolog Application
  • Nonlinear thermal network parameter identification method for power devices under variable operating conditions
    BAO Fengshuo, YING Zhanfeng, ZU Wei, LIU Zijian
    Advanced Technology of Electrical Engineering and Energy. 2026, 45(8): 103-112. https://doi.org/10.12067/ATEEE2508013
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    The thermal network models play a core role in the thermal design, thermal management and reliability assessment of electronic devices, which have evolved from classical linear models to nonlinear thermal network models that are more consistent with physical reality. In the practical application of nonlinear thermal models, the accurate determination of thermal parameters is a key factor to ensure the model accuracy. However, the traditional model parameter extraction method based on transient thermal impedance has strict requirements on the stability of working conditions, making it difficult to be applied to power semiconductor devices with variable working conditions in actual operation. To address this, this study proposes a parameter identification method for nonlinear thermal network models of power devices. The method constructs an objective function based on the nonlinear thermal network model and uses the particle swarm optimization (PSO) algorithm for global optimization to obtain the optimal solution of the model identification parameters. Experimental results verify that the method can accurately extract thermal parameters that are difficult to calculate theoretically, and it does not rely on constant working conditions, making it suitable for online use under actual variable working conditions. This provides a new approach to realize the reliability of junction temperature estimation engineering for power semiconductor devices.
  • Parallel current sharing regulation method for silicon carbide MOSFETs under differences of aging degree
    LI Kaiwei, SUN Pengju, MA Xing
    Advanced Technology of Electrical Engineering and Energy. 2026, 45(8): 113-124. https://doi.org/10.12067/ATEEE2504029
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Currently, the parallel use of silicon carbide (SiC) MOSFETs is the mainstream solution for high current carrying cases. However, under long time service conditions, the accumulation of time-varying non-uniform electro-thermal stresses will lead to different aging trajectories of the parallel devices, and this aging variability will trigger a positive feedback mechanism with different degrees of parameter drift-deterioration of parallel equalization of currents-local overstress- and accelerated parameter drift, which poses a threat to the reliability of the system. To this end, this paper proposes a parallel current sharing regulation method for SiC MOSFETs under different aging degree based on driving voltage compensation, aiming to achieve parallel dynamic current sharing under threshold voltage mismatch. First, a double-pulse test (DPT) platform and a Boost experimental platform for parallel connection of two tubes were built to deeply investigate the coupling effect between the different aging degree and the parallel current sharing; Then, the mathematical relationship between threshold voltage dispersion and turn-on voltage regulation is theoretically derived, and an current sharing regulation strategy based on driving voltage compensation is proposed and experimentally verified under different aging degrees. The results of this paper help to improve the reliability of SiC MOSFETs in parallel applications.
  • Research on optimal design of insulation corona protection for stator bar ends of large hydraulic turbine generators
    ZHANG Yandi, WEN Yingke, CHEN Jinxiu, LIU Feihui, HUANG Jiaxin
    Advanced Technology of Electrical Engineering and Energy. 2026, 45(8): 125-132. https://doi.org/10.12067/ATEEE2506056
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    With the development of hydraulic turbine generators towards higher rated voltages and larger single-unit capacities, higher requirements are placed on their insulation systems and corona protection performance. The electric field at the generator end is concentrated and unevenly distributed, making it a weak link prone to corona discharge. The currently adopted three-stage corona protection structure can meet the insulation performance requirements of generators under conventional operating conditions. However, with the increase in altitude, the influence of environmental parameters becomes gradually significant, necessitating a higher level of insulation corona protection capability to ensure the safe and stable operation of the generator set.In this paper, the Nelder-Mead algorithm is used to perform finite element electromagnetic simulations on the stator bars of a hydropower station's hydraulic turbine generator, optimizing the original three-stage corona protection structure and improving the generator's insulation corona protection capability. The results show that using the Nelder-Mead algorithm to optimize the corona protection materials and structure of the bars is fast in calculation speed and low in computational cost. Compared with the initial state, the optimized scheme reduces the maximum electric field strength on the bar surface by 20% under the rated operating voltage, and the optimized scheme performs well under other operating voltages. The optimal design method proposed in this paper can provide a reference for the insulation optimization design of high-voltage and large-capacity hydraulic turbine generators.
  • Optimization of medium voltage cable terminal pressure fitting using NSGA-II and TOPSIS
    LI Yan, TIAN Yongcai, ZENG Xiangrui, ZHAO Wenqian, DIAO Xun, LIU Yunpeng, HU Leilei, LI Mao
    Advanced Technology of Electrical Engineering and Energy. 2026, 45(8): 133-144. https://doi.org/10.12067/ATEEE2508001
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    The medium-voltage cable joint is a critical component that determines the overall safety and reliability of cable systems, with bolt compression serving as the key process influencing joint quality. In conventional cable bolt connection design, the final configuration is often determined empirically based on the designer’s experience, lacking a systematic and scientific optimization approach. In this study, a three-dimensional finite element model of the cable bolt was developed to analyze the stress distribution and fatigue life characteristics during the compression process. By integrating Matlab with finite element co-simulation, a quantitative relationship among bolt size, position, and compression performance was established. Taking stress life, maximum stress, and average stress as the three optimization objectives, the NSGA-II algorithm was employed to obtain a Pareto-optimal solution set, and the TOPSIS method was subsequently applied to identify the optimal structural configuration. The results demonstrate that rational optimization of bolt dimensions and positioning can approximately double the average contact stress and extend the fatigue life by about 1.5 times. The optimized design effectively reduces contact resistance while enhancing mechanical integrity and electrical stability. Both simulation and experimental results confirm that the proposed method significantly improves the safety and reliability of cable joints, providing theoretical and technical guidance for the engineering optimization of bolted compression structures.
　 Copyright © Advanced Technology of Electrical Engineering and Energy, All Rights Reserved.
Tel: 010-82547196　
E-mail：dgdnedit@mail.iee.ac.cn
Powered by Beijing Magtech Co. Ltd,.
Official website
official Account