Top Read Articles

    Published in last 1 year |  In last 2 years |  In last 3 years |  All
    Please wait a minute...
    For Selected: Toggle Thumbnails
    Optimal Reconfiguration Method for Thermoelectric Power Array Based on Artificial Bee Colony Algorithm
    YANG Bo, HU Yuanweiji, GUO Zhengxun, SHU Hongchun, CAO Pulin, LI Zilin
    Journal of Shanghai Jiao Tong University    2024, 58 (1): 111-126.   DOI: 10.16183/j.cnki.jsjtu.2022.284
    Abstract2525)   HTML10)    PDF(pc) (9997KB)(97)       Save

    With the rapid development of new energy generation technology, the thermoelectric generation technology (TEG) can make good use of the waste heat generated in new energy generation. However, the change of temperature distribution will worsen the output characteristics and reduce the power generation efficiency of the TEG system. In this paper, a TEG array reconfiguration method based on the artificial bee colony (ABC) algorithm is proposed. In three different temperature distributions, ABC is used for dynamic reconfiguration of symmetric 9×9 and unsymmetric 10×15 TEG arrays. Three meta-heuristic algorithms, the genetic algorithm, the particle swarm optimization algorithm, and the bald eagle search are compared with the proposed method, and the temperature distribution of the TEG array reconfiguration by ABC is given. The results show that ABC can improve the output power of the TEG array, and the output power-voltage curves tend to show a single peak value. In addition, real-time hardware-in-the-loop (HIL) experiment based on the RTLAB platform is undertaken to verify the implementation feasibility.

    Table and Figures | Reference | Related Articles | Metrics | Comments0
    Low-Carbon Operation Strategy of Integrated Energy System Based on User Classification
    ZHANG Chunyan, DOU Zhenlan, BAI Bingqing, WANG Lingling, JIANG Chuanwen, XIONG Zhan
    Journal of Shanghai Jiao Tong University    2024, 58 (1): 1-10.   DOI: 10.16183/j.cnki.jsjtu.2022.321
    Abstract2231)   HTML32)    PDF(pc) (1783KB)(323)       Save

    Integrated energy system (IES) is an important means to achieve the goal of “carbon peaking and carbon neutrality”. However, different types of users in the system have different energy consumption behaviors, which makes the coordinated optimization and low-carbon operation of the integrated energy system more difficult. In order to give full play to the subjective initiative of users, the user behavior of the integrated energy system is modelled based on user behavior analysis, and users are classified into aggressive and conservative types by convolutional neural network (CNN). Then, the decision model of integrated energy system operator is constructed to determine the supply mode of electric heating energy, and the corresponding energy package is designed for different types of users. Finally, the effectiveness of the above models and methods is analyzed based on actual data, and the value of user classification in low-carbon operation of integrated energy systems is verified.

    Table and Figures | Reference | Related Articles | Metrics | Comments0
    Improved Magnetic Circuit-Motion Coupled Model and Fast Simulation of Direct-Acting Electromechanical Motion Device
    JIANG Peng, GUAN Zhenqun, ZHAO Guozhong, ZHANG Qun, QIN Zhiqiang
    Journal of Shanghai Jiao Tong University    2024, 58 (1): 102-110.   DOI: 10.16183/j.cnki.jsjtu.2022.243
    Abstract2099)   HTML3)    PDF(pc) (3985KB)(217)       Save

    The rapid simulation of the dynamic performance of electromechanical devices such as solenoid valves and relays is important for product development and design. A magnetic circuit model of the non-saturated direct-acting electromechanical motion device is improved, and then coupled with the motion equation of the mechanism to realize the rapid simulation of the electromechanical motion device. In contrast to the ideal magnetic resistance in the conventional magnetic circuit model, the non-saturated total magnetic resistance is expressed by a cubic polynomial of the movement displacement of mechanism. The four undetermined coefficients of the polynomial are calibrated by the simulation values of static magnetic force and inductance at the upper and lower motion limits. The improved magnetic circuit model can more accurately predict the changes of magnetic attraction force and inductance with the motion displacement. Furthermore, coupled with the motion equation of the electromechanical motion device, the improved model establishes an improved magnetic circuit-motion coupled model and realizes fast second-level simulation of an electromagnetic brake and valve in the Simulink system, which can greatly reduce the finite element simulation time while maintaining simulation accuracy.

    Table and Figures | Reference | Related Articles | Metrics | Comments0
    A Method for Carbon Emission Measurement and a Carbon Reduction Path of Urban Power Sector
    HU Zhuangli, LUO Yichu, CAI Hang
    Journal of Shanghai Jiao Tong University    2024, 58 (1): 82-90.   DOI: 10.16183/j.cnki.jsjtu.2022.222
    Abstract1955)   HTML8)    PDF(pc) (1670KB)(263)       Save

    To measure and reduce carbon emissions in the urban power sector, a method for measuring carbon emissions in the urban power sector and a carbon reduction path are proposed. First, a carbon emission measurement model for the urban power sector is established based on the data of local power generation and net inward power. Then, carbon reduction measures for the urban power sector are proposed from the generation side, grid side, load side and energy storage side. After that, an evaluation model for the effect of the carbon reduction measures is established. Finally, taking a typical city F in the Pearl River Delta as an example, the proposed carbon emission calculation model is used to calculate the carbon emissions of power sector of the city, and the effectiveness of carbon reduction in 2030 carbon peak scenario of the city is evaluated based on the carbon reduction measures. The results show that the proposed model can accurately measure the carbon emissions of the urban power sector, and by utilizing carbon reduction measures, carbon emissions of the city can be reduced by at least 10.6 million tons in 2030.

    Table and Figures | Reference | Related Articles | Metrics | Comments0
    Robust Evaluation Method of Integrated Energy System Based on Variable Step Simulation and Improved Entropy Weight Method
    FAN Hong, HE Jie, TIAN Shuxin
    Journal of Shanghai Jiao Tong University    2024, 58 (1): 59-68.   DOI: 10.16183/j.cnki.jsjtu.2022.186
    Abstract1936)   HTML6)    PDF(pc) (5076KB)(178)       Save

    As an important manifestation of the energy Internet, the integrated energy system improves the energy utilization rate. However, it also brings more risks due to the high coupling and the large difference in the response speed between the various systems. From the perspective of system security, it becomes crucial to accurately identify the weak links in the system and evaluate the robustness of the system. Therefore, a robustness evaluation method combining variable step size simulation and improved entropy weight method is proposed in the complex network environment. First, the structure of the integrated energy system is introduced and the coupling links of the system are further explained. Then, the robustness indicators including network damage degree and connectivity factor are proposed, and a variable step according to the difference of the response time of different systems is adopted. Based on the simulation results, an improved entropy weight method is proposed, and a more objective evaluation method is constructed. Finally, the superiority of the evaluation method is verified by a case study.

    Table and Figures | Reference | Related Articles | Metrics | Comments0
    Comprehensive Evaluation of Key Technologies in Power Internet of Things Based on Comprehensive Similarity of Cloud Model
    CHEN Lianfu, ZHONG Haiwang, TAN Zhenfei, RUAN Guangchun
    Journal of Shanghai Jiao Tong University    2024, 58 (1): 19-29.   DOI: 10.16183/j.cnki.jsjtu.2022.420
    Abstract1887)   HTML15)    PDF(pc) (1954KB)(105)       Save

    Currently, the comprehensive evaluation of the application of key technologies in the power Internet of Things (PIoT) has the characteristics of a single evaluation object, and the traditional evaluation methods are not applicable. In order to comprehensively evaluate the technology maturity and operational effectiveness of PIoT projects, a comprehensive evaluation index for key technologies in PIoT is established to comprehensively consider the different development stages. According to the characteristics of application scenario, an evaluation model based on the comprehensive similarity of cloud model is proposed. By reforming the technique for order preference by similarity to an ideal solution (TOPSIS) method, a decision matrix for a single evaluation object is constructed, and the shape-distance comprehensive similarity of the cloud model is used as a measure to characterize the relative closeness of the TOPSIS method, and the accurate evaluation of a single object is realized. Finally, the proposed method is applied to assess a PIoT demonstration project. The results show that the proposed comprehensive evaluation index and evaluation method can objectively and comprehensively evaluate the comprehensive application effect of each key technology in the construction and operation stages of PIoT.

    Table and Figures | Reference | Supplementary Material | Related Articles | Metrics | Comments0
    Reliability Index Calculation and Reserve Capacity Optimization Considering Multiple Uncertainties
    YE Lun, OUYANG Xu, YAO Jiangang, YANG Shengjie, YIN Jungang
    Journal of Shanghai Jiao Tong University    2024, 58 (1): 30-39.   DOI: 10.16183/j.cnki.jsjtu.2022.366
    Abstract1852)   HTML7)    PDF(pc) (1413KB)(126)       Save

    In power systems with a high proportion of renewable energy, to achieve coordinated optimal scheduling of source and load considering multiple uncertainties is an important issue in power system operation. Therefore, a probabilistic spinning reserve optimization model based on multiple scenarios is constructed. Multiple uncertain factors are considered in the model, such as wind power and solar power forecast errors, load forecast error and unscheduled generator outage. Renewable energy curtailment and load shedding are used as special reserve resources in the day-ahead security-constrained unit commitment (SCUC) to improve the economic operation efficiency. The calculations of reliability indexes, expected energy not served and expected energy curtailment, are simplified, and the inequality constraints related to these two indexes are reduced, which improves the computational performance of the model. The model optimizes the total expected cost considering multiple uncertainties. Case studies based on the IEEE-RTS demonstrate the effectiveness of the proposed model. The numerical results show that the improved calculation method of reliability indexes can effectively reduce the solution time of the SCUC model. The reserve optimization model can realize the dynamic allocation of the spinning reserve capacity of the system and improve economic operation of the system.

    Table and Figures | Reference | Related Articles | Metrics | Comments0
    Optimization Design of New Bionic Propeller
    WU Chunxiao, LU Yu, LIU Shewen, GU Zhuhao, SHAO Siyu, SHAO Wu, LI Chuang
    Journal of Shanghai Jiao Tong University    2023, 57 (11): 1421-1431.   DOI: 10.16183/j.cnki.jsjtu.2022.174
    Abstract1736)   HTML27)    PDF(pc) (10709KB)(351)       Save

    A novel method for optimal design of hydrodynamic performance of bionic propeller with a deformable leading edge is proposed. Based on the bionics principle and method of parameterized modeling, the fore-fin concave-convex structure of humpback whales is applied to the propeller leading edge, the leading edge in the propeller to meet flow region according to the exponential decay curve and the standard sine curve smooth leading edge for similar humpback fins protuberant structure of concave and convex deformation, and the leading edge of concave and convex bionic propeller. The hydrodynamic performance, the cavitation performance, and the noise performance of the exponential decay bionic propeller and the sinusoidal function bionic propeller were simulated respectively. The propeller with a better performance is selected, and the simulation based design (SBD) technology is introduced into the optimization design of the new bionic propeller. The parameters controlling the shape of the exponential attenuation curve of the guide edge deformation are taken as optimization design variables, the torque of the parent propeller is taken as the constraint condition, the open water efficiency is selected as the objective function, and the optimization algorithm of Sobol and T-Search is adopted. A bionic propeller optimization system based on the exponential decay curve is constructed. The results show that the application of the concave and convex structure of the humpback whale fore-fin to the guide edge of the propeller improves the cavitation performance and noise performance of the propeller, but the improvement of the open water performance of the propeller is not particularly significant. It is verified that the hydrodynamic performance optimization design method of the bionic propeller established in this paper is effective and reliable, which provides a certain theoretical basis and technical guidance for the performance numerical calculation and configuration optimization design of the bionic propeller.

    Table and Figures | Reference | Related Articles | Metrics | Comments0
    Stepwise Inertial Intelligent Control of Wind Power for Frequency Regulation Based on Stacked Denoising Autoencoder and Deep Neural Network
    WANG Yalun, ZHOU Tao, CHEN Zhong, WANG Yi, QUAN Hao
    Journal of Shanghai Jiao Tong University    2023, 57 (11): 1477-1491.   DOI: 10.16183/j.cnki.jsjtu.2022.157
    Abstract1676)   HTML16)    PDF(pc) (10551KB)(190)       Save

    Stepwise inertial control (SIC) provides a step-increase of power after load fluctuation, which can effectively prevent system frequency decline and ensure the safety of grid frequency. However, in the power recovery stage, secondary frequency drop (SFD) is easy to occur. Therefore, it is necessary to optimize SIC to obtain a better frequency regulation effect. The traditional method has the disadvantages of high calculation dimension and long consuming time, which is difficult to meet the requirements of providing the optimal control effect in different scenarios. In order to realize the optimal stepwise inertial fast control of wind power frequency regulation in load disturbance events, this paper introduces the deep learning algorithm and proposes a stepwise inertial intelligent control of wind power for frequency regulation based on stacked denoising autoencoder(SDAE) and deep neural network(DNN). First, sparrow search algorithm (SSA) is used to obtain the optimal parameters, and SDAE is used to extract the data features efficiently. Then, DNN is used to learn the data features, and the accelerated adaptive moment estimation is introduced to optimize the network parameters to improve the global optimal parameters of the network. Finally, the stepwise inertial online control of wind power frequency regulation after disturbance event is realized according to SDAE-DNN. The simulation analysis is conducted for a single wind turbine and a wind farm in the IEEE 30-bus test system. Compared with the results obtained by the traditional method, shallow BP neural network and original DNN network, it is found that the proposed network structure has a better prediction accuracy and generalization ability, and the proposed method can achieve a great effect of stepwise inertia frequency regulation.

    Table and Figures | Reference | Related Articles | Metrics | Comments0
    Refined Simulation of Near-Surface Wind Field of Atmospheric Boundary Layer Based on WRF-LES Model
    LIU Dalin, TAO Tao, CAO Yong, ZHOU Dai, HAN Zhaolong
    Journal of Shanghai Jiao Tong University    2024, 58 (2): 220-231.   DOI: 10.16183/j.cnki.jsjtu.2022.415
    Abstract1674)   HTML22)    PDF(pc) (9950KB)(387)       Save

    Extreme meteorological disasters such as typhoons pose a serious threat to the safety of engineering structures. Therefore, the refined simulation on the near-surface atmospheric boundary layer (ABL) is valuable for civil engineering. Large-eddy simulation (LES) implemented in the weather research and forecating (WRF) model has the advantages of multiple options of numerical schemes and high accuracy. It is generally suitable for the refined simulation of the near-surface wind field, although the performance of simulation results is closely related to the numerical methods. This paper assesses the impacts of vital parameters regarding subfilter-scale (SFS) stress models, mesh size, and spatial difference schemes within WRF-LES to simulate the ideal ABL in order to figure out appropriate numerical schemes for the refined simulation of the near-surface wind field. The wind field characteristics are addressed and analyzed such as mean wind speed profile, turbulence intensity profile, and power of spectrum. Comparisons of simulation results among different SFS stress models indicate that the nonlinear backscatter and anisotropy one (NBA1) SFS stress model can effectively improve the accuracy of simulation in the near-surface wind profiles. Investigations of mesh resolution effects indicate that the nonuniformly refined vertical grid near the surface agrees much better with the expected profiles and reduces the expenditure of computational resources. Furthermore, the results show that the even-order spatial difference schemes produce more small-scale turbulent structures than the odd-order difference schemes. The numerical methods of WRF-LES proposed can provide a technical reference for refined simulation of the near-surface wind field and typhoon boundary layer.

    Table and Figures | Reference | Related Articles | Metrics | Comments0
    Wake Field Characteristics of Non-Ducted and Ducted Propellers in Large-Angle Oblique Flow
    ZHANG Qin, WANG Xinyu, WANG Zhicheng, WANG Tianyuan
    Journal of Shanghai Jiao Tong University    2023, 57 (11): 1432-1441.   DOI: 10.16183/j.cnki.jsjtu.2022.159
    Abstract1662)   HTML11)    PDF(pc) (18498KB)(175)       Save

    In order to explore the wake characteristics of non-ducted and ducted propellers in oblique inflow with a large drift angle, based on the delayed detached eddy simulation, a numerical simulation of non-ducted and ducted propellers in oblique inflow is conducted with an advance coefficient (J=0.4) and a large drift angle (β=45°, 60°). It is found that the deflection degree of the non-ducted propeller wake is higher than that of the ducted propeller. However, the overall distribution area of the wake vortex behind the ducted propeller is kinked. The wake field in the oblique flow shows its complexity, and the evolution process of vortices on the windward side differs from that on the leeward side. The above characteristic of the non-ducted propeller is more prominent. At the same time, the leading edge of the nozzle on the leeward side will produce local shedding vortices and transmit to the downstream due to flow separation. Part of the kinetic energy of the ducted propeller is converted into the nozzle thrust, which makes the turbulence kinetic energy of the wake lower than that of the non-ducted propeller. This phenomenon is more evident with the increase in the drift angle. Compared with the non-ducted propeller, the ducted propeller can maintain a better handling stability in large-angle oblique flow. This paper analyzes the influence of large-angle oblique inflow on the non-ducted and ducted propellers from the perspective of wake field characteristics and explores the theoretical basis for the ducted propeller to maintain a better handling stability in oblique flow.

    Table and Figures | Reference | Related Articles | Metrics | Comments0
    Analysis of Fluid-Structure Coupling Energy Transfer Characteristics Slender Structure with Variable Cross-Section at Low Reynolds Number
    DENG Xiubing, YU Yuemin, PANG Xiyuan
    Journal of Shanghai Jiao Tong University    2023, 57 (11): 1400-1409.   DOI: 10.16183/j.cnki.jsjtu.2022.133
    Abstract1654)   HTML11)    PDF(pc) (18587KB)(149)       Save

    The wavy deformed cross-section cylindrical structure has excellent properties of drag reduction in fluid flow, but the flow-induced vibration characteristics of flexible structure with such variable cross-section are still unclear. In this paper, based on the high-performance spectral element method, a fluid-structure coupled mechanistic model and a numerical algorithm for slender structures are established. The wake characteristics, structural dynamic responses, energy transfers, and spanwise variations of vortex shedding frequencies are discussed. The numerical simulation results show that slender structure with the wavy-deformed cross-section can greatly suppress the vortex-induced vibration response at an appropriate cross-section disturbance wave height, and the special vortex structure formed on both sides of the wavy-shaped slender structure can stabilize the flow around the shear layer and elongate the vortex formation length, thereby reducing the fluid-structure coupling effect between the wake structure and the slender structure, and suppressing the vortex-induced vibration response.

    Table and Figures | Reference | Related Articles | Metrics | Comments0
    Strategy of Wind-Storage Combined System Participating in Power System Secondary Frequency Regulation Based on Model Predictive Control
    LIU Chuanbin, JIAO Wenshu, WU Qiuwei, CHEN Jian, ZHOU Qian
    Journal of Shanghai Jiao Tong University    2024, 58 (1): 91-101.   DOI: 10.16183/j.cnki.jsjtu.2022.217
    Abstract1627)   HTML5)    PDF(pc) (2262KB)(192)       Save

    With the increasing penetration of wind power in power grids, it is necessary for wind storage joint farms to participate in power grid frequency modulation to maintain frequency stability of the power grid. By analyzing the mechanical characteristics of the wind turbine and the operation characteristics of the energy storage system, this paper determines the adjustability of the wind turbine power output in the pitch angle load shedding operation mode, and proposes a control strategy for the wind farm with an energy storage system to participate in the secondary frequency regulation of the power grid based on model predictive control (MPC). It establishes a prediction model for pitch angle control of the wind farm and an electrochemical energy storage system, optimizing the active power output of the wind turbine and the energy storage system, and better reducing the wind energy loss based on frequency regulation. The pitch angle control is further corrected based on the difference between the active power command value of the superior system and the actual power output of the wind turbine, so that the wind turbine can better track the power command value of the superior system during secondary frequency regulation, quickly respond to the frequency changes, reduce the dynamic frequency deviation, avoid load rejection due to too low frequency drop, and complete the task of secondary frequency regulation. The simulation results show that under the control strategy proposed in this paper, the controllable secondary frequency regulation ability of the wind turbine and the characteristics of fast response and accurate tracking of the energy storage system are comprehensively considered, the active power command issued by the superior system is better tracked, and the task of the wind farm including the energy storage system participating in the secondary frequency regulation is realized.

    Table and Figures | Reference | Related Articles | Metrics | Comments0
    Optimization of Wind Turbine Vortex Generator Based on Back Propagation Neural Network
    XIA Yunsong, TAN Jianfeng, HAN Shui, GAO Jin’e
    Journal of Shanghai Jiao Tong University    2023, 57 (11): 1492-1500.   DOI: 10.16183/j.cnki.jsjtu.2022.169
    Abstract1607)   HTML12)    PDF(pc) (9995KB)(173)       Save

    The optimal Latin hypercube experimental design method is used to refine the vortex generator parameters, determine the test scheme, simulate and calculate the thrust and torque of the wind turbine, and obtain the experimental data. Based on the back propagation (BP) neural network, the aerodynamic performance model of the wind turbine vortex generator optimized by genetic algorithm is constructed. The reliability of the aerodynamic performance model is verified by calculating the error and root mean square of the predicted and simulated values of the aerodynamic performance model. Coupling the fish swarm algorithm and the aerodynamic performance model of the wind turbine vortex generator, an optimization method of the wind turbine vortex generator is established, and the height, length, and installation angle of the vortex generator are solved iteratively to realize the optimization of the vortex generator. The results show that compared with the original vortex generator scheme, the flow separation of the wind turbine blade section optimized by the vortex generator is effectively restrained and delayed, the surface fluid separation phenomenon is improved, the power of the wind turbine is increased by 1.711%, and the thrust of the wind turbine is decreased by 0.875%.

    Table and Figures | Reference | Related Articles | Metrics | Comments0
    Experimental Investigation of Dynamic Response of Pile-Supported Wharf in Liquefiable Ground Under Wave Action
    BI Jianwei, SU Lei, XIE Libo, ZHANG Yu, LING Xianzhang
    Journal of Shanghai Jiao Tong University    2023, 57 (11): 1442-1454.   DOI: 10.16183/j.cnki.jsjtu.2022.163
    Abstract1601)   HTML9)    PDF(pc) (8259KB)(239)       Save

    Pile-supported wharf (PSW) is widely used in the deep-water port engineering construction, most of which are located in liquefiable ground. The effect of wave action on the working performance of PSW in liquefiable ground cannot be ignored, but few studies have been reported. This study performs the wave flume test of PSW in liquefiable ground considering the soil-structure-wave interaction. This test really reproduces the operating condition of PSW, and explores the internal response difference of wharf structure under wave. The influence of wave height on dynamic response of the PSW system is discussed systematically. The result shows that the acceleration and displacement of the PSW deck gradually increase first and finally remain relatively stable with the increase of wave action. The hydrodynamic pressure and deformation of each pile in pile group are obviously different, and the response variation is related to the pile position. The pore pressure of the soil layer in the free field and around the pile decreases with the increase of depth, and the existence of the pile group can reduce the pore pressure in the soil layer around the pile, and increase the acceleration of the soil layer. The effect of wave height on the soil layer decreases with the increase of depth. The above results can provide reference for the similar PSW test under wave and the support for the design and wave protection of PSW.

    Table and Figures | Reference | Related Articles | Metrics | Comments0
    Robust Optimization of Power Grid Investment Decision-Making Considering Regional Development Stage Uncertainties
    HUANG Wandi, ZHANG Shenxi, CHENG Haozhong, CHEN Dan, ZHAI Xiaomeng, WU Shuang
    Journal of Shanghai Jiao Tong University    2023, 57 (11): 1455-1464.   DOI: 10.16183/j.cnki.jsjtu.2022.053
    Abstract1575)   HTML14)    PDF(pc) (2782KB)(89)       Save

    Aimed at the problem of uncertainties in the regional development stage and the difficulties in quantifying regional investment demand in different development stages, a robust optimization method for power grid investment decision-making considering regional development stage uncertainties is proposed to promise the matching degree between power grid investment decisions and development needs, and to improve the ability of decision-making results to deal with portfolio risks and uncertainties in regional development stage. First, investment risk constraints are constructed based on the modern portfolio theory. Then, a box uncertainty set is used to characterize uncertainties in regional development stage, and a robust optimization model for power grid investment decision-making considering uncertainties in development stage is established. In the optimization model, the outer minimization problem is used to solve the uncertain variables in regional development stage in the worst scenario, while inner maximization problem is used to obtain the decision-making plan that can maximize investment return in the worst scenario. Furthermore, according to the strong duality theory, the double-layer optimization model is transformed into a single-layer model that can be solved directly, and the big-M method is used to solve the model proposed. Finally, an actual example of 13 cities in an eastern coastal province verifies the applicability and effectiveness of the power grid investment decision-making model.

    Table and Figures | Reference | Related Articles | Metrics | Comments0
    An Improved NLC and Capacitor Voltage Control Method for Medium-/Low-Voltage MMCs
    ZHANG Wei, HAN Junfei, ZHONG Ming, WANG Yuqiang
    Journal of Shanghai Jiao Tong University    2023, 57 (11): 1465-1476.   DOI: 10.16183/j.cnki.jsjtu.2022.172
    Abstract1503)   HTML12)    PDF(pc) (2806KB)(146)       Save

    The modular multilevel converter (MMC) suffers from low output level and high harmonic distortion in medium-/low-voltage applications such as direct current (DC) distribution networks. In addition, the capacitor voltage of MMC is coupled with DC bus voltage in the traditional modulation method, leading to large fluctuations of capacitor voltages and deviation from the rated value under DC bus voltage margin. In order to solve the problems above, this paper proposes an improved nearest level control method, which can increase the output level of medium-/low-voltage MMCs by introducing a step wave correction. Based on the proposed modulation method, a capacitor voltage feedback control is thus proposed to limit the range of capacitor voltage fluctuations and improve equipment safety. The effectiveness of the proposed method is verified by MATLAB/Simulink simulation and real-time digital simulation system hardware-in-the-loop test.

    Table and Figures | Reference | Related Articles | Metrics | Comments0
    Source-Load Matching Analysis and Optimal Planning of Wind-Solar-Thermal Coupled System Considering Renewable Energy Ramps
    XIA Qinqin, LUO Yongjie, WANG Rongmao, ZOU Yao, LUO Huanhuan, LI Jincan, ZHOU Niancheng, WANG Qianggang
    Journal of Shanghai Jiao Tong University    2024, 58 (1): 69-81.   DOI: 10.16183/j.cnki.jsjtu.2022.260
    Abstract1396)   HTML8)    PDF(pc) (3526KB)(99)       Save

    Wind, photovoltaic, and thermal power generation can form a coupled system through the same grid-connected point, which is a high coordination and low-carbon approach of renewable energy and flexible regulating power source at generation side in northern China. By considering renewable energy ramps and source-load matching analysis, this paper studies the optimal capacity planning of a wind-solar-thermal coupled system to provide reference for coupled system planning. First, the operation model and the uncertainty method of coupled system are briefly described. Then, considering the wind-solar complementary, ramp events, and critical load characteristics, relevant indices are selected and proposed for source-load matching evaluation. After that, considering the constraints of source-load characteristics, matching, and cost, an optimal capacity planning model of wind-solar-thermal coupled system is established. Finally, based on the actual data in Liaoning Province, a case study is conducted to acquire the optimal capacity of the wind and solar generation in the area, and the interaction between the source-load relevant indices and the planning results is analyzed, which provides reference and suggestion for the optimal capacity planning of renewable energy generation.

    Table and Figures | Reference | Related Articles | Metrics | Comments0
    Simulation Study of Reentry Dynamics of a Deep-Water Drilling Riser System Based on Model Predictive Control
    ZHANG Chenyu, MENG Shuai
    Journal of Shanghai Jiao Tong University    2023, 57 (11): 1389-1399.   DOI: 10.16183/j.cnki.jsjtu.2022.235
    Abstract1361)   HTML25)    PDF(pc) (2622KB)(210)       Save

    A marine drilling riser at normal operation condition is required to disconnect the lower marine riser package (LMRP) and blow-out preventer (BOP) in case of severe weather. When the weather gets fine, it must reconnect the LMRP and the BOP. This process is called riser reentry. Marine drilling operations have been driven into extreme deep-waters characterized by severe weather which inevitably leads to a much higher incidence of disconnection. In addition, it requires to accomplish the reentry in a fast way owing to the capricious ocean environment. This study tries to develop a novel reentry control system based on model predictive control (MPC). First, the transverse governing equation of the hanging-off riser system with an end-mass is established based on the modified Hamilton’s principle. The optimization function and constraints in MPC are designed by use of the riser prediction model and the target location. A nonlinear disturbance observer is established for compensation of the model uncertainties and ocean environment disturbances. Finally, simulations are conducted after introducing the dynamic position system (DPS). The riser dynamics employing MPC are compared with that when adopting proportional-integral-derivative (PID) controller. It has found that the drilling riser system based on MPC has a higher response speed, which can complete the reentry process in a faster and more stable manner. It can handle the hydrodynamic force model uncertainties well and has a good robustness for current velocity disturbances. As the flexibility of the riser system is notably enhanced with the significant increase of aspect ratio, the higher-order mode of the flexible hanging-off riser can be triggered in the fast reentry process subjected to the excitations of the mother vessel and ocean environment.

    Table and Figures | Reference | Related Articles | Metrics | Comments0
    Fast Stability of New Power System Based on a PMU Gradient Dynamic Deviation Method
    YU Miao, HU Jingxuan, ZHANG Shouzhi, WEI Jingjing, SUN Jianqun, WU Yixiao
    Journal of Shanghai Jiao Tong University    2024, 58 (1): 40-49.   DOI: 10.16183/j.cnki.jsjtu.2022.370
    Abstract1348)   HTML3)    PDF(pc) (2171KB)(120)       Save

    The high proportion of renewable energy and power electronic equipment is emerging as a significant trend and key characteristic of the power system development driven by the dual promotion of the energy transformation and scientific technological advancement. Major modifications have been made to the dynamic behavior of the new power system. The traditional small signal stability analysis approach is difficult to apply, and there are still urgent issues to be resolved for the quick change of operating conditions. In this paper, a Lyapunov direct analysis method of gradient dynamic deviation based on phasor measurement unit (PMU) data is proposed to analyze the small signal stability of the new power system. First, the PMU data matrix is used to reduce the dimension to obtain the low dimension matrix, which is substituted into the power system matrix model with a doubly-fed induction generator (DFIG). The diagonal matrix is obtained by solving the Lyapunov equation, and the positive definiteness of the matrix is determined to judge the system stability. Then, the dynamic deviation of corresponding state variable is calculated by solving the obtained diagonal matrix. The gradient descent method is applied to the corresponding state variable curve to iterate the extreme point value of curve. The time-weighted dynamic deviation of the whole oscillation process is calculated by time weighting, which provides guidance for the subsequent configuration position of damping stability controller, i.e., power system stabilizer (PSS). The method can improve the small interference stability of the system. The effectiveness of the fast stability analysis of the new power system is verified by simulations of the new England 10-machine 39-bus system with DFIG.

    Table and Figures | Reference | Related Articles | Metrics | Comments0
    Fully Distributed Economic Dispatch of Combined Heat and Power System Considering Individual Selfishness
    MI Yang, WU Jiwei, TIAN Shuxin, MA Siyuan, WANG Yufei
    Journal of Shanghai Jiao Tong University    2024, 58 (1): 50-58.   DOI: 10.16183/j.cnki.jsjtu.2022.495
    Abstract1325)   HTML4)    PDF(pc) (1726KB)(74)       Save

    In response to the defects of the traditional centralized economic dispatching strategy which needs to obtain global information and cannot adapt to the flexible topology of the system, and considering the coexistence of energy in the form of electricity and heat, a completely distributed cogeneration economic dispatching strategy based on the consistency algorithm is proposed. The incremental cost of electricity price and heat price of each unit in the cogeneration system is taken as the consistent variable to conduct the iterative calculation until the incremental cost converges to achieve the economic optimum of the system. In addition, the case of individual unit transmitting to neighboring units with deviating incremental cost values in order to enhance their own interests is also analyzed, and an incremental cost compensation term is designed to eliminate the impact of this selfish behavior. The simulation results indicate that the proposed strategy is effective and viable in the solution of the cogeneration economic dispatching problems.

    Table and Figures | Reference | Related Articles | Metrics | Comments0
    Green Energy Trading in Distribution Network Considering Credit Value
    WU Qing, JIA Qiangang, YAN Zheng, ZHONG Zhun, GUO Song, LI Zhiyong
    Journal of Shanghai Jiao Tong University    2024, 58 (1): 11-18.   DOI: 10.16183/j.cnki.jsjtu.2022.130
    Abstract1110)   HTML16)    PDF(pc) (1504KB)(205)       Save

    Developing distributed renewable energy is vital to energy system transformation, while organizing market trading will promote the production and consumption of distributed renewable energy. However, the uncertainty of renewable energy output causes deviations during market delivery, which threats the security of distribution system operation. It is still difficult for existing market-based trading mechanisms to motivate market players to reduce the deviations. Therefore, this paper gives guidance to the honest delivery behaviors of distributed green energy producers by quantifying credit costs. Considering the strategic bidding behaviors of distributed green energy producers, it establishes a market model taking the credit costs into account. Then, it proposed an iterative algorithm based on the optimal response theory to calculate the Nash equilibria of the green energy market. The results of the case study show that the market mechanism proposed can give guidance to the integrity behavior of green energy producers in an incentive-compatible way, reducing the delivery deviation while improving social welfare.

    Table and Figures | Reference | Related Articles | Metrics | Comments0
    A Review of Numerical Studies of Wave Impacts on Marine Structures
    ZHANG Nianfan, XIAO Longfei, CHEN Gang
    Journal of Shanghai Jiao Tong University    2024, 58 (2): 127-140.   DOI: 10.16183/j.cnki.jsjtu.2022.500
    Abstract1106)   HTML24)    PDF(pc) (4659KB)(168)       Save

    Wave impact is a strongly nonlinear interaction between waves and structures, and its load usually has the characteristics of a large peak value and short duration. In recent years, the extreme environment has frequently led to severe wave impacts on marine structures, resulting in loss of life and property, thus making the issue of wave impact become a great concern. For the complicated impact process, the theoretical analysis and model experiments can only provide simplified analytical solution and limited information on the slamming flow field. Therefore, numerical simulation has gradually become an effective means to study the issue of wave impact. Scholars at home and abroad have conducted a large number of numerical investigations on the load characteristics of wave impact, impact process, and its influencing factors on marine structures, gaining numerous important research conclusions. In this paper, the current progress, existing methods, and important conclusions of the numerical study of wave impact on marine structures are reviewed, which can provide useful references for further research on the numerical simulation of wave impact.

    Table and Figures | Reference | Related Articles | Metrics | Comments0
    Numerical Analysis of Hydrodynamic Performance of Propeller in Waves
    ZHANG Geng, YAO Jianxi
    Journal of Shanghai Jiao Tong University    2024, 58 (2): 175-187.   DOI: 10.16183/j.cnki.jsjtu.2022.247
    Abstract1093)   HTML10)    PDF(pc) (14901KB)(231)       Save

    The hydrodynamic performance of propeller is mostly studied in calm water, but the propeller working behind ship is often affected by waves. According to the literature, there is relatively little research on hydrodynamic performance of propeller in waves at present. In view of this, RANS solver based on OpenFOAM is used to calculate and analyze the influence of waves on the thrust and torque of propeller. The results show that time history curves of thrust and torque oscillate under the influence of waves. The disturbance of free surface and the oscillation amplitude of time history curves increase with the decrease of immersion depth and advance coefficient. Compared with the calm water condition, the average thrust and torque of propeller in waves are reduced when the immersion depth and advance coefficient are the same. The computational results are in good agreement with the experimental data.

    Table and Figures | Reference | Related Articles | Metrics | Comments0
    Prediction of Slip and Torsion Performance of Right-Angle Fasteners Based on Machine Learning Methods
    BAO Zhujie, LI Zhen, WANG Feiliang, PANG Bo, YANG Jian
    Journal of Shanghai Jiao Tong University    2024, 58 (2): 242-252.   DOI: 10.16183/j.cnki.jsjtu.2022.399
    Abstract1066)   HTML7)    PDF(pc) (11483KB)(122)       Save

    Aiming at the issue of large CPU costs and low calculation accuracy in the design of right-angle fasteners in scaffolding structures, prediction models of fastener anti-slip performance and torsion performance based on machine learning are proposed. A three-dimensional solid model of right-angle fasteners is established using the finite element method, the effectiveness of the numerical simulation method is verified through test results, and the comprehensive influence of various design parameters on the performance of fasteners is revealed by the parametric analysis method. The database is established by combining the test and numerical simulation results, and the fastener stiffness prediction models are proposed based on random forest (RF), support vector machine (SVM) and K-most proximity algorithm (K-NN), respectively. The expressions for the measured point displacement of the anti-slip model and the stiffness prediction of the torsion model are proposed in combination with genetic expression programming. The results indicate that SVM and GEP can predict the displacement and torsional stiffness of right-angle fasteners more accurately, which is important for guiding the safety design of fasteners in engineering scaffolding structures.

    Table and Figures | Reference | Related Articles | Metrics | Comments0
    Layout Optimization Design of Human Machine Interface in Wheelhouse Based on Ergonomics
    JI Yuheng, LI Chuntong, LUO Xiaomeng, YANG Xuelian, WANG Deyu
    Journal of Shanghai Jiao Tong University    2024, 58 (2): 201-210.   DOI: 10.16183/j.cnki.jsjtu.2022.401
    Abstract1056)   HTML11)    PDF(pc) (6622KB)(148)       Save

    To solve the problems of empiricism, subjectivity and randomness in the manual layout of human machine interface in wheelhouse, an optimization layout design method of human machine interface that combines virtual simulation and optimization algorithm is proposed. First, the optimal operating point and the operating comfort of each area of the human machine interface are obtained through virtual simulation. Then, the layout criteria and ergonomics criteria of human machine interface are quantified as objective functions and constraints, a layout optimization mathematical model of human machine interface is established, and a large number of initial positions of the particles in the particle swarm optimization (PSO) algorithm are obtained through the differential evolution algorithm. Finally, the optimal layout scheme is obtained, and virtual simulation evaluation is conducted. Taking a control panel as an example for layout optimization and virtual simulation, the optimal layout scheme obtained is proved to satisfy ergonomic criteria, and the performance of the human machine interface has been improved. This paper can provide references for the layout design of the high performance human machine interface in wheelhouse.

    Table and Figures | Reference | Related Articles | Metrics | Comments0
    In-Situ X-Ray CT Characterization of Damage Mechanism of Plain Weave SiCf/SiC Composites Under Compression
    CHENG Xiangwei, ZHANG Daxu, DU Yonglong, GUO Hongbao, HONG Zhiliang
    Journal of Shanghai Jiao Tong University    2024, 58 (2): 232-241.   DOI: 10.16183/j.cnki.jsjtu.2022.322
    Abstract1052)   HTML5)    PDF(pc) (27080KB)(199)       Save

    In order to reveal the damage evolution and failure mechanism of ceramic matrix composites (CMCs), in-situ X-ray CT compression tests of plain weave SiCf/SiC composites were conducted, and the CT data during loading and after failure were obtained. Displacement and strain distributions of the material were evaluated by the digital volume correlation (DVC) technology. The three-dimensional visual model of the composite was created by using image processing software. The spatial distributions of tow split and other damages were segmented by the deep learning algorithm. The qualitative and quantitative analysis of compression damage evolution were performed. The results show that there is a relatively large expansion induced by barreling in the thickness direction and a little shrinkage in the width direction during the unidirectional compression, while the barreling in the thickness direction is the main reason to trigger compressive damages of the material. Damages such as matrix falling-off at surface, tow split, delamination, will occur as the compression was approaching the ultimate load. Fiber kinking results in the final compressive failure of the material, while an obvious V-shaped shear band is observed in the fracture. The analysis of compressive damage evolution of plain weave SiCf/SiC shows that the DVC technology and deep learning-based image segmentation methods could effectively reveal the compressive damage evolution mechanism of ceramic matrix composites.

    Table and Figures | Reference | Related Articles | Metrics | Comments0
    Inverse Reconstruction of Environmental Loads and Virtual Model Test
    LI Xu, XIAO Longfei, WEI Handi, WU Wencheng, ZHU Ziyang, LI Yan
    Journal of Shanghai Jiao Tong University    2024, 58 (2): 141-146.   DOI: 10.16183/j.cnki.jsjtu.2022.398
    Abstract1041)   HTML10)    PDF(pc) (3587KB)(76)       Save

    Novel methods of inverse reconstruction of environmental loads and virtual model test for hybrid model test are proposed. The environmental loads are extracted from the physical truncated model test, considering the nonlinear effects such as coupling effect among the six-degrees-of-freedom (6 DOF) motions and wave slamming, and viscous force of the fluid. The loads can be further applied to the numerical model in virtual wave basin to conduct virtual model test with truncated and full-depth mooring system. Wave basin tests under combined wave, wind, and current condition are conducted to validate the proposed methods, and the results show that the environmental loads can be accurately reconstructed from the physical model tests.

    Table and Figures | Reference | Related Articles | Metrics | Comments0
    Load-Reducing Characteristics of Gas Screen During Underwater Launch of the Vehicle
    SHI Yao, LU Jiewen, DU Xiaoxu, GAO Shan, REN Jinyi
    Journal of Shanghai Jiao Tong University    2024, 58 (2): 211-219.   DOI: 10.16183/j.cnki.jsjtu.2022.323
    Abstract1005)   HTML2)    PDF(pc) (6389KB)(126)       Save

    During the underwater launching process, a gas screen channel is formed near the opening of the cylinder, which can effectively reduce the high-frequency pulsation load on the surface of the vehicle exiting the cylinder. Based on the volume of fluid (VOF) homogeneous multiphase flow theory, the standard RNG k-ε turbulence model, and the overlaid grid technology, this paper studies the influence law of the gas screen on the surface of the vehicle to improve the pulsating load of the vehicle, and analyses the flow field structure and hydrodynamic evolution under the gas screen environment. The characteristics of the gas curtain flow field structure evolution and the discharge load reduction effect at different cross-flow intensities and gas mass flow rates were compared. The results show that the high-speed gas ejected from the nozzles approximately covers the surface of the vehicle during the exiting process, and gradually forms a gas channel around the opening of the launch vessel, thereby reducing the surface load of the vehicle significantly. Under the condition of gas screen, both the moment and the surface load on the body have been significantly reduced, with the peak value of the moment reduced by 80.3%, and the peak pressure on the surface of the vehicle reduced by 81.2%. However, the peak pressure on the surface of the vehicle increases by a maximum of 56.7% upon increasing cross-flow intensity. Finally, the mass flow rate increases from 2 kg/s to 16 kg/s, with the moment on the vehicle reduced by 80.8% and the peak surface pressure reduced by 82.8%.

    Table and Figures | Reference | Related Articles | Metrics | Comments0
    An Artificial Neural Network-Based Method for Prediction of Ice Resistance of Polar Ships
    SUN Qianyang, ZHOU Li, DING Shifeng, LIU Renwei, DING Yi
    Journal of Shanghai Jiao Tong University    2024, 58 (2): 156-165.   DOI: 10.16183/j.cnki.jsjtu.2022.316
    Abstract1002)   HTML9)    PDF(pc) (1823KB)(70)       Save

    Accurate prediction of ice resistance plays an important role in ensuring the safety of ship sailing in polar navigation in ice areas. In recent years, machine learning has been widely used in the field of ships, among which artificial neural network (ANN) is a common method. The focus of this paper is to design an ANN model for predicting the ice resistance of polar ships. According to the traditional empirical and semi-empirical formula, appropriate input characteristic parameters are selected. The radial basis function (RBF) neural network model is built based on a large number of ship model test data, and the genetic algorithm (GA) is used to optimize the model. The research shows that the radial basis function neural network model optimized by genetic algorithm (RBF-GA) based on seven characteristic parameters input has good generalization effect. Compared with the model test and full-scale test data, the average error is about 8%, which shows that the RBF-GA model has a high accuracy, and can be used as a tool for ice resistance prediction.

    Table and Figures | Reference | Related Articles | Metrics | Comments0
    Calm Water Resistance Prediction and Navigation Posture Optimization of a New Unmanned Survey Catamaran
    CAI Junlei, YAO Tiancheng, LIU Hong, WAN Lijian, WAN Jun, FAN Xiang, ZHAO Yongsheng
    Journal of Shanghai Jiao Tong University    2024, 58 (2): 166-174.   DOI: 10.16183/j.cnki.jsjtu.2022.452
    Abstract999)   HTML9)    PDF(pc) (14650KB)(73)       Save

    In order to obtain the resistance performance and economic navigation posture of a new unmanned survey catamaran, a calm water resistance simulation of this catamaran is conducted by model tests, the empirical formula method, and the computational fluid dynamics (CFD) method. Further, the CFD method is used to explore the influence of different longitudinal positions of the center of gravity on the hull and perimeter waveform, and a suitable installation position is selected for the multi-beam acoustic equipment. The results show that the CFD method can accurately predict the navigation posture and resistance at all speeds, while the empirical formula method is mainly suitable when the speed is low (FrΔ<1.5). At the speed of 4 and 6 kn, the economic navigation posture is at a tail tilt of 1.4°. At this time, there is a relatively stable high water level area between the pieces of about 0.3 to 0.5 times of vessel length from the stern, which can be used as a suitable installation position for multi-beam acoustic equipment.

    Table and Figures | Reference | Related Articles | Metrics | Comments0
    Cost Sharing Mechanisms of Pumped Storage Stations in the New-Type Power System: Review and Prospect
    LIU Fei, CHE Yanying, TIAN Xu, XU Decao, ZHOU Huijie, LI Zhiyi
    Journal of Shanghai Jiao Tong University    2023, 57 (7): 757-768.   DOI: 10.16183/j.cnki.jsjtu.2021.516
    Abstract982)   HTML46)    PDF(pc) (2464KB)(498)       Save

    Driven by the carbon peaking and carbon neutrality goals, the power system is transforming to the new structure which is dominated by renewable energy and is facing a new supply-demand balance situation. Pumped storage, as the most mature energy storage technology at present, can provide flexible resources with different time scales to ensure the safety of the power system and promote the consumption of renewable energy. However, the operation strategy and cost sharing mechanism of the pumped storage station (PSS) are not clear, which hinders its further development under the new situation. In this context, the technical characteristics and functions of PSS are sorted out first. Then, the investment cost model is established from the perspective of the whole life cycle. After that, the evolution path of pricing mechanism and cost sharing mode are described in view of the different stages of electricity market development, providing a feasible scheme for the marketization of PSS. Finally, the future development of PSS is summarized and prospected.

    Table and Figures | Reference | Related Articles | Metrics | Comments0
    Dynamic Response of a Vessel-Shaped Fish Cage Considering Coupling Effect Among Body Motion, Disturbed Velocity Field, and Net Loads
    WANG Yihou, FU Shixiao, XU Yuwang, LI Shuai, FU Qiang, LIU Fuxiang
    Journal of Shanghai Jiao Tong University    2024, 58 (2): 147-155.   DOI: 10.16183/j.cnki.jsjtu.2022.404
    Abstract977)   HTML9)    PDF(pc) (10409KB)(47)       Save

    Vessel-shaped fish cages are a new type of large aquaculture structure consisting of a floating body, steel frames, net system, and mooring system. The diffraction and radiation waves induced by the floating body can disturb the velocity field and induce additional changes to the hydrodynamic loads on the nets. In this paper, the velocity transfer functions around the nets induced by the diffraction and radiation waves are obtained and the effects of floating body on the forces of the nets are calculated by the Morison equation. By performing the iterations between the motion of floating body and loads on the nets, the fully coupled dynamic response of motion-disturbing velocity field-net loads is realized. Finally, the effects of diffraction and radiation waves on motion response, tension in the net twine, volume reduction, and connector loads are investigated. The results show that the influences of disturbing velocity field on cage motion response and volume reduction are not obvious, but they can lead to a significant increase in the tension in net twine and connector loads, which can provide helpful reference for the structural strength analysis and safety design of vessel-shaped fish cages.

    Table and Figures | Reference | Related Articles | Metrics | Comments0
    An Rapid Prediction Method for Propeller Hydrodynamic Performance Based on Deep Learning
    GAO Nan, HU Ankang, HOU Lixun, CHANG Xin
    Journal of Shanghai Jiao Tong University    2024, 58 (2): 188-200.   DOI: 10.16183/j.cnki.jsjtu.2022.331
    Abstract966)   HTML6)    PDF(pc) (5139KB)(52)       Save

    In order to achieve rapid and accurate prediction of the hydrodynamic performance of propellers, a set of propeller hydrodynamic performance prediction model was established based on the improved residual connection network. The residual connection method greatly improves the depth of the model. In combination with the Inception structure to simultaneously extract data features from different scales, the depthwise separable convolution reduces the model parameters. The sample space for training the deep neural network is built based on the propeller geometric parameters and model test results. An improved beetle swarm antennae search algorithm is proposed to optimize the initial weights and thresholds of the model to further improve the prediction accuracy of the model. The research results indicate that the improved beetles swarm antennae algorithm significantly improves the accuracy of the model and solves the problem of overfitting of it. The prediction results of the model are in good agreement with the experimental values, and its prediction performance for the propellers which are not in the dataset is basically the same as that of the CFD method. The model has an excellent universality and its calculation period is extremely short, which can meet the requirements of real-time and accurate prediction of propeller open water performance.

    Table and Figures | Reference | Related Articles | Metrics | Comments0
    Chinese interpretation of Japanese Gastric Cancer Treatment Guidelines 2021 (6th edition) and Ruijin clinical practice
    YAN Chao, LU Sheng, YAN Min, ZHU Zhenggang
    Journal of Surgery Concepts & Practice    2023, 28 (04): 326-354.   DOI: 10.16139/j.1007-9610.2023.04.010
    Abstract959)   HTML23)    PDF(pc) (4954KB)(2740)       Save

    “Japanese Gastric Cancer Treatment Guidelines” have been important guidelines for the treatment of gastric cancer in Japan and worldwide. The English version “Japanese Gastric Cancer Treatment Guidelines 2021 (6th Edition)” published in January 2023 consists of two parts. The first part includes diagnostic and treatment methods, such as surgery, endoscopic resection, chemotherapy, follow-up. The second part addresses clinical issues, including recommendations and explanations for clinical hot topics. This article will provide a Chinese interpretation of the guidelines and briefly introduce our hospital's clinical practice in the diagnosis and treatment of gastric cancer.

    Table and Figures | Reference | Related Articles | Metrics | Comments0
    Multi-Objective Optimization of Electric Vehicle Spare Capacity Based on User Wishes
    SHAO Ping, YANG Zhile, LI Kang, ZHU Xiaodong
    Journal of Shanghai Jiao Tong University    2023, 57 (11): 1501-1511.   DOI: 10.16183/j.cnki.jsjtu.2022.131
    Abstract949)   HTML10)    PDF(pc) (5565KB)(126)       Save

    Due to the considerable number and the characteristics of energy storage, it is possible for electric vehicles (EVs) to participate in the operation and regulation of power system to provide reserve service. In view of this, a multi-objective optimal scheduling model is established based on the wishes of electric vehicle users, with the objectives of the economic benefits of electricity collectors, microgrid power fluctuations and user satisfaction. Considering the uncertainty of load demand, the optimal scheduling analysis of multi-time scale scenes with the day-ahead time scale and the intra-day real-time correction time scale is conducted. The mainstream multi-objective intelligent optimization algorithm NSGA-III algorithm is adopted in the solution method, and the NSGA-II and MOEA/D algorithms are used for comparison. The optimal dispatching scheme is selected through comparative experiments and scenarios where EVs provide spare capacity are analyzed. The simulation results verify the feasibility and effectiveness of the proposed model.

    Table and Figures | Reference | Related Articles | Metrics | Comments0
    Dynamic Characteristics of Two-Dimensional Structures Slamming Under Free Fall Condition
    SUN Zhe, SUI Xupeng, KOROBKIN Alexander, DENG Yanzeng, ZHANG Guiyong, ZONG Zhi, JIANG Yichen
    Journal of Shanghai Jiao Tong University    2023, 57 (11): 1410-1420.   DOI: 10.16183/j.cnki.jsjtu.2022.189
    Abstract883)   HTML16)    PDF(pc) (1402KB)(199)       Save

    The slamming process of two-dimensional structures under free fall condition with arbitrary symmetrical shapes is investigated by combining various analytical models for slamming and the precise integration method in the time domain. By closely analyzing the mathematical expression of analytical models, the total slamming force acting on the body can be decomposed into two terms which are dependent on the velocity and the acceleration respectively. The developed model proposed in this paper is validated against the results from experiments and other numerical methods. Moreover, it is found that if the gravity of body is ignored, which is a reasonable assumption for situations such as structures with light weight or large entry velocity, the maximum acceleration (or the peak slamming force) for a free fall body will always occur at the certain penetration depth for a particular shape and mass, regardless of the initial slamming velocity.

    Table and Figures | Reference | Related Articles | Metrics | Comments0
    Resilience Evaluation and Enhancement Strategy of Distribution Network Considering Impact of Seismic Attack on Transportation Networks
    YAN Wenting, YANG Long, LI Changcheng, LUO Wei
    Journal of Shanghai Jiao Tong University    2023, 57 (9): 1165-1175.   DOI: 10.16183/j.cnki.jsjtu.2022.152
    Abstract809)   HTML19)    PDF(pc) (2248KB)(275)       Save

    Serious earthquake disasters not only cause power outages in distribution network, but also destroy transportation networks, which hinders the transportation of resources for restoration of distribution network and slows down the restoration. This paper proposes an improved resilience evaluation method and a resilience enhancement strategy of distribution network considering the effects of seismic attack on transportation networks. First, a seismic attack model is established to describe the relation between earthquake disasters and failure probability of transportation-distribution networks based on peak ground acceleration. The impact of earthquake disasters on transportation-distribution networks is quantified, and the failure scenarios are generated. Then, a resilience evaluation index is proposed by introducing the waiting time for road repair of emergency repair teams. Afterwards, a bi-level optimization model for distribution network restoration considering the fault line repair, the road repair, and the emergency resource scheduling is established and solved. The upper layer aims at the minimum power loss load, while the lower layer takes the minimum waiting time of the repair team as the goal. Finally, case studies on a coupling example of a 12-node transportation network and an IEEE 33-node distribution network verify the feasibility of the improved resilience index and the effectiveness of the proposed method. The results show that the resilience index considering seismic attack on transportation networks is accurate, and the restoration strategy can effectively enhance the resilience of distribution network in earthquake disasters.

    Table and Figures | Reference | Related Articles | Metrics | Comments0
    A Microgrid Energy Management Strategy Considering Carbon Quota Guided Demand Response
    JIANG Enyu, CHEN Yu, SHI Zhengjing, WU Zhecheng, LIN Shunfu, LI Dongdong
    Journal of Shanghai Jiao Tong University    2023, 57 (9): 1126-1136.   DOI: 10.16183/j.cnki.jsjtu.2022.378
    Abstract773)   HTML16)    PDF(pc) (2823KB)(145)       Save

    In order to reduce the forecast output error caused by the randomness and volatility of renewable energy in microgrid operation, a microgrid energy management strategy considering carbon quota guided demand response is proposed. A two-layer model predictive control (MPC) energy management model is constructed. The upper layer guides electric vehicles to participate in the demand response of microgrid by constructing a carbon emission quota mechanism to realize the economic operation of microgrid and reduce carbon emissions. The lower layer uses the model predictive control rolling optimization and the power fluctuation caused by the prediction error of renewable energy is suppressed by the short time scale model predictive control. The results of calculation analysis show that the proposed energy management strategy can effectively guide electric vehicles or other controllable loads to participate in demand response and realize low-carbon economic dispatch and stable operation of microgrid.

    Table and Figures | Reference | Related Articles | Metrics | Comments0
    A Two-Stage Distributionally Robust Economic Dispatch Model Under the Coordination of Inter-Provincial and Intra-Provincial Bi-Level Market
    CHEN Yi, WANG Han, XU Xiaoyuan, HU Youlin, YAN Zheng, ZENG Dan, FENG Kai
    Journal of Shanghai Jiao Tong University    2023, 57 (9): 1114-1125.   DOI: 10.16183/j.cnki.jsjtu.2022.121
    Abstract714)   HTML19)    PDF(pc) (2373KB)(110)       Save

    To promote the optimal allocation of resources across the country, China is actively developing inter-provincial electricity transactions, and will gradually form an inter-provincial and intra-provincial electricity market operation mode. In this context, a two-stage day-ahead, and intraday economic dispatch framework considering inter-provincial and intra-provincial bi-level market coordinated operation is proposed. In the day-ahead dispatch stage, an inter-provincial and intra-provincial bi-level economic dispatch model is constructed. In the intraday dispatch stage, an economic dispatch model considering the forecast error of source-load is constructed. To further deal with the influence of the uncertainty of source-load forecast on economic dispatch, a two-stage day-ahead and intraday distributionally robust economic dispatch model and its solution method are proposed, realizing the economic dispatch under random scene ambiguity set. Finally, a multi-sending ends and multi-receiving ends interconnected test system is constructed using IEEE 39-bus and 118-bus systems. The effectiveness of the proposed model and method is verified by simulation.

    Table and Figures | Reference | Related Articles | Metrics | Comments0