23 May 2020, Volume 39 Issue 5
    

  • Select all
    |
    Treatise and Report
  • Analysis and control of output power of coupling mechanism of inductive power transfer system
    JIANG Long-bin, SHI Li-ming,FAN Man-yi, ZHANG Fa-cong, YIN Zheng-gang,
    Advanced Technology of Electrical Engineering and Energy. 2020, 39(5): 1-9. https://doi.org/10.12067/ATEEE1911014
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Due to manufacturing process and the diversity of device parameters, etc., the self-resonant frequencies of the primary and secondary coils of the inductive power transfer system (IPT) may be different. Usually, a controllable rectifier is used on the secondary side of the coupling mechanism to perform the impedance transformation to make the coupling mechanism operate at high efficiency condition. However, the maximum output power of the coupling mechanism will be severely restricted when the coupling mechanism operates at the primary or secondary coil self-resonant frequency. This paper proposes to set the switching frequency to a specific frequency point between the self-resonant frequencies of the primary and secondary coil to improve the maximum output power of the coupling mechanism while maintaining the highest efficiency. Firstly, the expressions of the maximum output power of the coupling mechanism with the same and different self-resonant frequencies of the primary and secondary coils are deduced. The reason why the maximum output power of the coupling mechanism is low is analyzed. Then, the maximum output power of the coupling mechanism maintaining the highest efficiency is improved by setting the switching frequency to a specific frequency point between the self-resonant frequencies of the primary and secondary coil. The experimental results show that, compared with using primary resonant frequency, the maximum output power of the coupling mechanism is increased by 92.5% using the switching frequency setting method proposed in this paper.
  • Research on control strategy of DFIG participating in secondary frequency regulation based on pitch control
    LIU Liu, WANG De-lin, YANG Ren-jie, SONG Wen-feng, YANG Feng-bo, ZHANG Jun-wu, KANG Ji-tao
    Advanced Technology of Electrical Engineering and Energy. 2020, 39(5): 10-16. https://doi.org/10.12067/ATEEE1903039
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Aiming at the problem that the traditional thermal equivalent circuit model has large error in calculating the junction temperature of IGBT module, an equivalent thermal impedance model of IGBT module based on heat transfer research is proposed. By studying the heat transfer inside IGBT module, the heat spreading angle is determined according to the law of heat flux variation. Thermal network parameters are calculated and an improved equivalent circuit model of single chip Cauer network is established. Then, considering the thermal coupling effect between multi-chips, the self-heating thermal impedance and coupling thermal impedance are calculated and the thermal impedance matrix of IGBT module is established. The junction temperature of each chip can be predicted by using the linear superposition principle. Finally, the junction temperature calculated by the equivalent thermal impedance model is compared with the finite element simulation value, which verifies the effectiveness and accuracy of the model.
  • Thermal impedance model for IGBT modules considering heat spreading and thermal coupling
    HE Yi-gang, ZHANG Zhong-tao, LIU Jia-cheng, ZHAO Ming, LI Chen-chen
    Advanced Technology of Electrical Engineering and Energy. 2020, 39(5): 17-24. https://doi.org/10.12067/ATEEE1904033
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Aiming at the problem that the traditional thermal equivalent circuit model has large error in calculating the junction temperature of IGBT module, an equivalent thermal impedance model of IGBT module based on heat transfer research is proposed. By studying the heat transfer inside IGBT module, the heat spreading angle is determined according to the law of heat flux variation. Thermal network parameters are calculated and an improved equivalent circuit model of single chip Cauer network is established. Then, considering the thermal coupling effect between multi-chips, the self-heating thermal impedance and coupling thermal impedance are calculated and the thermal impedance matrix of IGBT module is established. The junction temperature of each chip can be predicted by using the linear superposition principle. Finally, the junction temperature calculated by the equivalent thermal impedance model is compared with the finite element simulation value, which verifies the effectiveness and accuracy of the model.
  • Comparative analysis and comprehensive evaluation of different simplified Preisach models
    LI Yi-ling,LI Lin, LIU Ren,HAN Yu,LIU Yang
    Advanced Technology of Electrical Engineering and Energy. 2020, 39(5): 25-31. https://doi.org/10.12067/ATEEE1907001
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    The simplified Preisach model is widely used in the simulation of hysteresis and loss characteristics of power equipment because of its high precision and fast calculation speed. In this paper, two different simplified Preisach models are presented, which are compared and analyzed from three aspects: hysteresis loop simulation accuracy, loss solution accuracy and calculation speed. Experiments and simulations show that the simplified Preisach model proposed by Ragusa (model 1) has some improvements in the hysteresis loop simulation under low magnetic density after considering the reversible component(model 1 considers that the magnetization process is divided into two parts: reversible magnetization and irreversible magnetization), but little improvement under high magnetic density. The calculated global average error of the loss calculation is reduced from 1234% to 957%. The model considering the reversible component is slightly better than the simplified Preisach model proposed by Naidu (model 2), and the accuracy of the hysteresis loop is slightly improved. The global average error of model 1 and model 2 is 957% and 781%, respectively for the accuracy of loss calculation. In the solution speed, model 1 is significantly slower than model 2 because it contains complex integrals. Therefore, under comprehensive consideration, it is recommended to select model 2 in the simulation of hysteresis and loss characteristics of magnetic materials.
  • Risk assessment of sub-synchronous oscillation of Guilin power grid with doubly-fed wind farms based on impedance network analysis
    LI Ling,ZHUO Yi-xin,CUI Chang-jiang,WU Chuan-tao, SUI Quan,LIANG Zhen-cheng, ZHANG Yi-hui,LIN Xiang-ning
    Advanced Technology of Electrical Engineering and Energy. 2020, 39(5): 32-40. https://doi.org/10.12067/ATEEE1906036
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    In this paper, the impedance network analysis method is used to explore the potential risk of large-scale wind power integration into the Guilin network to induce subsynchronous oscillation. Firstly, aiming at the complex grid structure of Guilin network area, an impedance network analysis method suitable for complex power system analysis is proposed. The frequency domain impedance model is established based on the electrical characteristics of the doubly-fed induction generator. On this basis, combined with the grid structure and line parameters of Guilin network area, the impedance analysis is carried out for the two modes of operation: normal operation and anti-icing operation. Finally, based on the PSCAD time domain simulation platform, the impedance analysis results are verified. The results show that under the normal operation mode, there is almost no risk of subsynchronous oscillation in Guilin network area. However, under the anti-ice operation mode, the risk of subsynchronous oscillation in Guilin network area is higher.
  • Short-term load forecasting method based on IPSO-LSVM
    CHENG Zhi-you,DING Bai-hong, YU Guo-xiao
    Advanced Technology of Electrical Engineering and Energy. 2020, 39(5): 41-48. https://doi.org/10.12067/ATEEE1905003
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Traditional short-term load forecasting model based on SVM has problems in that input variables are difficult to determine and model parameters are difficult to optimize. Aiming at these two shortcomings, this paper proposes a short-term load forecasting method based on IPSO-LSVM. Firstly, the LASSO regression is introduced to select the lagging load in the SVM prediction model, and the screening results and the remaining influencing factors are used as input variables in the SVM prediction model to establish a coupled model of LASSO and SVM (LSVM). Secondly, the IPSO algorithm is used to optimize the parameters in the LSVM prediction model to improve the accuracy and stability of the prediction results. Finally, the optimized model is used for prediction. The analysis of numerical example shows that the IPSO algorithm for LSVM can effectively improve the accuracy of short-term load forecasting.
    • Summary and Review
  • Summary of power control methods for wave power generation system
    LIU Hua-bing,PENG Ai-wu,ZHAO Ling-zhi,
    Advanced Technology of Electrical Engineering and Energy. 2020, 39(5): 49-58. https://doi.org/10.12067/ATEEE1909007
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Wave energy power generation is an effective means of utilizing clean and renewable marine energy. Because of the instability and dispersion of wave energy, the energy conversion efficiency of wave power generation system is low, which restricts the development of wave power generation technology. Therefore, it is necessary to adopt a certain power control method to make full use of wave resources and improve wave energy conversion efficiency in wave power generation system. In this paper, the power control theory of wave power generation, amplitude-phase control and complex conjugate control, is briefly introduced. Various power control methods proposed at home and abroad in recent years are classified and analyzed. The development trend of power control research is expounded. Wave prediction and intelligent control are the research hotspots in the future, considering the large scale in the future. It is necessary to study the multi-objective optimal control problem of combining power control objectives with other control objectives for grid-connected array wave power generation devices.
    • New Technology Application
  • Detection of multiple power quality disturbance based on adaptive modified incomplete S-transform
    CHENG Zhi-you,WU Ji, LIU Dang-dang, CHEN Liang
    Advanced Technology of Electrical Engineering and Energy. 2020, 39(5): 59-65. https://doi.org/10.12067/ATEEE1904075
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    According to the problem that the S-transform is not ideal when analyzing the non-stationary composite power quality disturbance in distribution network, a new method to detect the disturbance is proposed based on adaptive modified incomplete S-transform. By introducing adaptive window adjustment factor to adjust the scale of Gauss window, the time-frequency resolution of different power quality disturbance can be satisfied. Firstly, the multi-scale maximum algorithm is used to extract the feature frequencies of the multiple power quality disturbance events. Then by defining the residual difference curve to amplify the power quality disturbance mutation local part, the number of pulses can be obtained and this is used as a basis to combine the feature frequencies so as to adaptively determine the window adjustment factor. Finally, the feature frequencies are transformed locally to realize the adaptive detection of the signal. The simulation experiment and measured signal analysis show that the proposed method has strong anti-noise, low computational complexity and high detection accuracy, and is suitable for time-frequency analysis of power quality disturbance signals.
  • ANP method for evaluating level of integrated energy services
    CHI Fu-jian, GE Lei-jiao, WANG Yu-qian, HE Ping, WANG Zhe, LI Gui-xin
    Advanced Technology of Electrical Engineering and Energy. 2020, 39(5): 66-73. https://doi.org/10.12067/ATEEE1902023
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Integrated energy service is an important direction of future business transformation of power grid enterprises. Aiming at the problem that there are many factors affecting the comprehensive energy service level and it is difficult to quantitatively analyze them, this paper proposes a comprehensive evaluation method of the comprehensive energy service level based on ANP. Firstly, a comprehensive evaluation index system of comprehensive energy service level is constructed from five aspects: management level, economic benefit, operation effect, social impact and sustainable development level, which includes 5 first-level indicators and 16 second-level indicators. Secondly, in order to achieve comprehensive evaluation, ANP method is used to solve the corresponding weight of the proposed comprehensive energy service level evaluation index. Through the analysis of typical cases, it is known that the economic benefit and operation effect are the key factors among the first-level indicators, and the energy conversion efficiency, network comprehensive loss, user comfort and regional economic impact are the important indicators among the second-level indicators, so as to provide reference for the operation and development of future integrated energy service providers.
  • Heat dissipation optimization design for temperature field of GIS disconnecting switch based on shield opening
    CHEN Shi-ping, CONG Hao-xi, LI Qing-min
    Advanced Technology of Electrical Engineering and Energy. 2020, 39(): 74-80. https://doi.org/10.12067/ATEEE1906015
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    The overheating phenomenon of GIS contacts may cause major accidents. Therefore, it is important to study on the optimization of internal temperature field heat dissipation for the design and operation of GIS equipment. Taking the actual single-phase GIS disconnecting switch as an example, the two-dimensional electromagnetic heat flow coupled field simulation model was established by finite element analysis. On the basis of comprehensive consideration of factors such as radiative heat dissipation, gas convection, eddy current loss and gravity acceleration, the distribution characteristics of internal temperature field of GIS were analyzed for different shield structure design schemes. The research results indicate that, for the flat GIS equipment, the top temperature is higher than the bottom temperature at the same radius, and the characteristics are symmetrically distributed. As the convection heat dissipation of the SF6 gas in the cylinder is strong, the internal SF6 gas exhibits a curved S-shaped distribution. The opening of shield cannot reduce the heat source, but it has a significant effect on accelerating the natural convection heat dissipation of the gas and reducing the temperature rise of the inner conductor. By using a symmetrical structure to open the shield, the maximum electric field strength inside the GIS is lower than that of the actual circular shield and the engineering breakdown electric field strength, and will not cause electric field distortion as well as partial discharge failure. Finally, considering the heat dissipation effect and the degree of electric field distortion, a heat dissipation optimization design scheme based on symmetric opening structure was proposed, which can provide some reference value for heat dissipation optimization design and temperature monitoring of GIS equipment.
　 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