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Table of Content

    28 March 2022, Volume 56 Issue 3 Previous Issue    Next Issue
    New Type Power System and the Integrated Energy
    A Review of Coupled Electricity and Hydrogen Energy System with Transportation System Under the Background of Large-Scale New Energy Vehicles Access
    LI Jiaqi, XU Xiaoyuan, Yan Zheng
    2022, 56 (3):  253-266.  doi: 10.16183/j.cnki.jsjtu.2021.464
    Abstract ( 4321 )   HTML ( 963 )   PDF (2106KB) ( 1312 )   Save

    The large-scale utilization of renewable energy is an important way to achieve the “double carbon targets”. The technology of coupled renewable energy with hydrogen system can improve the consumption rate of renewable energy and the penetration of new energy vehicles. The coupling between the electricity-hydrogen energy system and the transportation system will be even closer in the future. Based on the access of large-scale new energy vehicles, first, the development of the electricity and hydrogen energy system was summarized, and the three working modes of electricity-hydrogen coupling system including hydrogen production, output smoothing, and coordinated operation with electricity network were introduced. Then, the research status of the electricity-transportation coupling system on planning and optimal operation, and the problems of hydrogen-transportation coupling system on hydrogen refueling station optimization and hydrogen transportation were analyzed. Finally, in combination with the existing bottlenecks, the future feasible research directions such as dynamic model construction and the influence of uncertain factors were proposed.

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    Review of Research on Condition Assessment of Nuclear Power Plant Equipment Based on Data-Driven
    XU Yong, CAI Yunze, SONG Lin
    2022, 56 (3):  267-278.  doi: 10.16183/j.cnki.jsjtu.2021.502
    Abstract ( 3963 )   HTML ( 321 )   PDF (1383KB) ( 1475 )   Save

    The condition assessment of the entire life cycle of nuclear power equipment has a significant impact on improving the safety and economy of nuclear power plants. In the past, operation and maintenance of systems, equipment, and structures of domestic nuclear power plants, mostly relied on the alarm mechanism of equipments, the simple threshold judgments of parameters, or the empirical judgments of engineers. With the implementation of online monitoring system in nuclear power plants, a large number of equipment operation data have been accumulated, and the use of data-driven technology to assess the health of equipment has become the focus of attention in the industry. In this paper, the current situation of the online monitoring system of nuclear power equipment was introduced and the common malfunction of nuclear power equipment was analyzed. The condition assessment of nuclear power equipment were categorized into three major problems (i.e., anomaly detection, life prediction, and fault diagnosis), the situation of research and application were summarized respectively, and the application potential of deep learning technology in this field was emphasized. Based on this, the challenges and possible solutions to the condition assessment of nuclear power plant equipment were further analyzed.

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    Optimization of Active Distribution Network Operation Considering Decarbonization Endowment from 5G Base Stations
    ZENG Bo, MU Hongwei, DONG Houqi, ZENG Ming
    2022, 56 (3):  279-292.  doi: 10.16183/j.cnki.jsjtu.2021.367
    Abstract ( 4266 )   HTML ( 388 )   PDF (3102KB) ( 1018 )   Save

    The massive access of 5G base stations (5G BSs) provides new possibilities for the low-carbon development of future power systems. By incentivizing 5G BSs to participate in demand response and incorporating them into the existing active distribution network (ADN) operation framework, the cost of the electricity consumption of 5G BSs can be reduced while promoting the consumption and efficient use of renewable energy sources (RES). This paper proposes a multi-objective interval optimization model for ADN operation considering low-carbon empowerment of 5G BSs. Based on the interaction mode between 5G BSs and the distribution network, a 5G BSs operating flexibility description model is constructed, and the system dynamics method is used to reveal the mechanism of 5G BSs on carbon emission reduction on the distribution side. Taking the minimization of system operating cost and carbon emissions as the goals, and considering the constraints for both the distribution network and the communication network, a multi-objective optimization model for ADN operation with 5G BSs is established. The model cooptimizes the dispatch of RES and 5G equipment, and adopts an interval method to consider the uncertainty of RES output and communication loads, which can achieve simultaneous optimization of system economy and low-carbon benefits. Combining the equivalent transformation and the non-dominated sorting genetic algorithm to solve the problem, the results of numerical studies prove the effectiveness of the proposed method.

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    Low-Carbon Transformation of the Power System in the Guangdong-Hong Kong-Macao Greater Bay Area
    ZHANG Pengfei, XU Jingyi, GUO Wei, WU Wei, ZHONG Chen, WEI Wendong
    2022, 56 (3):  293-302.  doi: 10.16183/j.cnki.jsjtu.2021.436
    Abstract ( 4318 )   HTML ( 392 )   PDF (2818KB) ( 818 )   Save

    China’s “carbon peaking and carbon neutrality” goal relies greatly on the low-carbon transition of the power system, but the existing research rarely explores the low-carbon transition of the regional power system. By using the intergovernmental panel on climate change (IPCC) greenhouse gas inventory compilation method and the network model analysis, the carbon emissions caused by the power generation and the power consumption in Guangdong-Hong Kong-Macao Greater Bay Area (the Greater Bay Area) was quantified. The logarithmic mean Divisia index (LMDI) method was used to quantify the influence of socio-economic factors on the electricity-related carbon emissions in the Greater Bay Area. The results show that Hong Kong and Macao have made slow progress in the low-carbon transition of the power system, and Guangdong’s share of the low-carbon power continues to increase. The rapidly expanding economic scale and the power demand were the most important drivers of the emissions growth in the Greater Bay Area. The low-carbon electricity imported from outside regions and the improved efficiency in the sectoral electricity consumption offset part of the emission growth.

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    Control Strategies for Suppressing Frequency Oscillation of Doubly-Fed Wind Farms Connected to Grid
    LIU Xinyu, LU Xinyan, ZENG Long, HAO Zhenghang, ZHAO Qifang, LI Xianwei, HAO Tongmeng
    2022, 56 (3):  303-311.  doi: 10.16183/j.cnki.jsjtu.2021.437
    Abstract ( 4239 )   HTML ( 247 )   PDF (1481KB) ( 829 )   Save

    Aimed at the problem of low-frequency oscillations caused by cross-region power transmissioin of large-scale wind farms, a single neuron adaptive proportion integration differentiation (PID) additional damping control strategy for low-frequency oscillations of the damping system is proposed in this paper. By analyzing the dynamic frequency response characteristics of doubly-fed wind turbines, a wind farm damping system oscillation controller is constructed by introducing quadratic performance indicators into the single neuron adaptive PID control algorithm. By adaptively adjusting the excitation frequency converter, the wind farm can quickly generate active power and the maximum positive damping, and suppress the low-frequency oscillation of the damping system. MATLAB is used to build a four-machine two-region power system simulation model with a wind farm. The comparison verifies that the method proposed in this paper can effectively suppress the swing of the power angle of the synchronous generator when low-frequency oscillation occurs in the system, improve the inertial response of the system, and reduce the risk of low-frequency oscillation in the power grid.

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    Performance Evaluation Index and Method of Micro-Grid Distributed Electricity Trading Under the Background of “Carbon Peaking and Carbon Neutrality”
    WANG Wenbin, ZHENG Shujiang, FAN Ruixiang, CHEN Wen, ZHOU Shiyang
    2022, 56 (3):  312-324.  doi: 10.16183/j.cnki.jsjtu.2021.391
    Abstract ( 3612 )   HTML ( 214 )   PDF (2446KB) ( 608 )   Save

    With the rapid development of distributed power generation research and application, the distributed trading market, as a new type of power trading mode, can effectively increase the consumption rate of renewable energy and is an important means to promote the realization of the goal of “carbon peaking and carbon neutrality”. Introducing the market evaluation mechanism into distributed transactions will prompt users to consider the impact of the market evaluation mechanism on their trading strategies and promote the sound development of the distributed transaction market. The distributed power trading market among micro-grid users is studied in this paper. First, taking the market participants and transaction supporting software and hardware as the research object, a multi-dimensional performance evaluation index system is established from the aspects of power supply capacity, user satisfaction, and platform security. Next, the research status of distributed power trading market evaluation methods is summarized. The key technologies of distributed power trading performance evaluation are analyzed from the establishment of index system, the index calculation method, and the comprehensive evaluation method. Finally, in combination with the current development status, the research direction of the distributed power trading performance evaluation in the future is prospected.

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    A Dual Cooperative Optimization for Optimal Redundancy Quantity of MMC Submodules of Flexible Controller
    MA Zhoujun, WANG Yong, WANG Jie, CHEN Shaoyu
    2022, 56 (3):  325-332.  doi: 10.16183/j.cnki.jsjtu.2021.444
    Abstract ( 3443 )   HTML ( 235 )   PDF (922KB) ( 514 )   Save

    The failure of modular multilevel converter (MMC) submodules in the flexible direct current (DC) system affects the normal operation of the system, and the mutual restriction of reliability and economy is one of the key issues of MMC redundancy configuration optimization. A multi-objective optimization function of MMC reliability and economy mathematical model with redundant submodules was established. Based on the weight coefficient and NSGAII multi-objective optimization methods, a dual collaborative optimization for redundancy quantity of flexible controller was proposed. Combining the advantages of the two methods, the intersection of the two optimization results was calculated under the same redundancy quantity selection preference. A model based on a DC project in a flexible station area of Nanjing was built in MATLAB. The simulation results prove that the proposed method can not only meet the reliability of the flexible DC system, but also significantly improve the economy. It provides ideas for redundancy quantity of MMC submodules in the actual flexible DC project.

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    A Suppression Strategy for Subsequent Commutation Failures Considering Commutation Capability of Recovery Process
    CONG Xinpeng, ZHENG Xiaodong, CAO Yaqian, TAI Nengling, MIAO Yuancheng, LI Ke
    2022, 56 (3):  333-341.  doi: 10.16183/j.cnki.jsjtu.2021.004
    Abstract ( 3807 )   HTML ( 237 )   PDF (1969KB) ( 524 )   Save

    In order to suppress subsequent commutation failures of high voltage direct current (HVDC), the dynamic process of electrical and control quantities during system recovery is studied, and the main reason for subsequent commutation failures is proposed in the paper. During the recovery process, the voltage of the converter bus after the fault is in a state of drop, the actual firing angle of the inverter is in overshoot, and direct current continues to rise. These factors result in an insufficient system commutation capability to complete the transfer of valve arm inductance energy during the commutation process. A suppression strategy for subsequent commutation failure considering the commutation capability of the system recovery process is proposed. By limiting the direct current (DC) when the firing angle is in overshoot, the system commutation capability is increased, and subsequent commutation failures are suppressed. In addition, the DC system is effectively recovered. The proposed theory is tested and verified based on the HVDC CIGRE Benchmark in PSCAD/EMTDC.

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    An Improved TDOA Lightning Location Approach Considering L-M Algorithm and Acoustics
    LUO Yaoying, BIAN Hongzhi, LIU Quanzhen, LIU Baoquan, FU Zhengcai, ZHANG Jianxun, LIU Yakun
    2022, 56 (3):  353-360.  doi: 10.16183/j.cnki.jsjtu.2020.301
    Abstract ( 3163 )   HTML ( 295 )   PDF (3403KB) ( 558 )   Save

    In the conventional lightning location system (LLS) based on time difference of arrival (TDOA), the nonlinear equations in lightning location calculation easily get to be divergent when the time information acquired from electromagnetic sensors is redundant. The LLS setup in lightning-sensitive regions in China usually experiences a development from detecting the thunderclap signal to the electromagnetic signal, such as the LLSs in oil tank farms. Therefore, an improved TDOA lightning location approach was proposed considering the acoustic and electromagnetic information emitted from lightning discharges. The targeted lightning monitoring region was divided into 16 sub-regions according to the location of the existing detection stations. The lightning location was calculated based on the Levenberg-Marquardt (L-M) iterative algorithm, which improves the lightning location accuracy and the resistance ability to measuring errors. The results show that the average error of the traditional lightning location method is 203.2 m. In contrast, the proposed approach can reduce the lightning location error to 108.4 m by considering the acoustic information and L-M iteration algorithm. The location accuracy at the edge of the targeted area is improved by 51.2%. This research can be potentially counseled in the improvement of existing LLSs and making an effective use of acoustic information.

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    Naval Architecture, Ocean and Civil Engineering
    Uncertainty Analysis of Offshore Platform Wind Load Tests
    DAI Yi, CHEN Zuogang, WANG Fei
    2022, 56 (3):  361-367.  doi: 10.16183/j.cnki.jsjtu.2021.066
    Abstract ( 3987 )   HTML ( 75 )   PDF (2064KB) ( 512 )   Save

    The superstructures of offshore platforms are usually complex in shape, and wind tunnel test is the most reliable method to obtain the wind loads. Few researches about the procedures of uncertainty analysis (UA) and key points have been conducted, and the influences of error sources are not clear. The UA of an offshore platform wind load tests is first performed based on the International Towing Tank Conference (ITTC) recommended procedures. According to the wind load test procedure of the offshore platform, the uncertainties due to many error sources are analyzed. In order to obtain the remark of all error sources and propose the approach of reducing uncertainties, error sources are evaluated and graded. The results show that the wind profile, the accuracy of the model, the air pressure measurement, and the balance measuring state have a great influence on wind load coefficients, which contribute to 96.13% of the combined uncertainty. The uncertainties can be effectively reduced by model simplification, high quality wind profile, high precision air pressure measurement, and stable measurement state.

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    Numerical Simulation and Analysis of Cylindrical Ice Impacting Problem
    WANG Chao, YANG Bo, ZHANG Yuan, GUO Chunyu, YE Liyu
    2022, 56 (3):  368-378.  doi: 10.16183/j.cnki.jsjtu.2020.278
    Abstract ( 3935 )   HTML ( 71 )   PDF (4968KB) ( 833 )   Save

    In order to study the application characteristics of the peridynamics (PD) method in the field of ice mechanical behavior and the sensitivity analysis of parameter changes in the numerical prediction of ice failure, the ordinary state-based peridynamic method is employed to systematically analyze the impact failure process of cylindrical ice in the present work. The results show that the simulated ice impact process by the proposed method is basically consistent with the test results, and the calculation results converge under the selected time step and particle spacing. The impact velocity, Poisson’s ratio, and the elastic modulus of the ice have remarkable effects on the impact process of ice cylinder, while the size and fracture toughness of the ice only have little influence. The innovation of this paper lies in the fact that the state-based PD method is applied to study the ice impact problem, which compensate for the shortcomings of the bond-based PD method that limits the Poisson’s ratio of the ice.

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    Optimization of Control Scheme for Large Flow Seawater Cooling System Based on FloMaster-Simulink Co-Simulation
    WANG Ning, FU Yunpeng, LI Ting, LI Tie, YI Ping
    2022, 56 (3):  379-385.  doi: 10.16183/j.cnki.jsjtu.2021.023
    Abstract ( 3580 )   HTML ( 90 )   PDF (1498KB) ( 645 )   Save

    Large-scale marine equipment will overheat if it works for a long time and a cooling system is necessary to be established to ensure that the equipment works in a safe range of temperature. To meet the cooling requirements of a large-scale marine equipment, a model of seawater cooling system is established in FloMaster, and simulations under dynamic conditions are conducted. According to the temperature of the coolant (glycol solution) in the front or back of the room of the heat exchanger, the pump speed or valve opening is changed to realize automatic control of seawater flow. Three control schemes are proposed, and the control effects are evaluated by the response characteristics and operating characteristics of the system under variable working conditions using the FloMaster-Simulink co-simulation method. The results show that when the pump speed is controlled by both the open loop and closed loop, the best control effect and lower energy consumption can be achieved.

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    Aeronautics and Astronautics
    Influence of Pressurization Methods on Cryogenic Helium Pressurization in Rocket Fuel Tank
    ZOU Zhenfeng, REN Feng, LI Xiaoci, DUAN Haiyang, DU Hailang, HUANG Yonghua
    2022, 56 (3):  386-394.  doi: 10.16183/j.cnki.jsjtu.2020.265
    Abstract ( 3876 )   HTML ( 78 )   PDF (13239KB) ( 685 )   Save

    To verify the technical scheme of cryogenic helium pressurization in the fuel tank of liquid oxygen (LOX)-kerosene rocket, a test device was established and the ground simulation test was conducted. The influences of different pressurization methods on pressure control stability, ullage temperature distribution in tank, helium consumption, gas-liquid mixture, and liquid freezing of pressurized drainage process were investigated. The pressurization method specifically includes pressurization outlet position, diffuser form, and pressurant flow rate. The results show that when pressurized from the liquid zone, the heat exchange of pressurized gas is more sufficient, which reduced the gas consumption by 33.1% compared with that in the ullage zone. However, the stability of pressure control is less satisfying. The form of diffuser has little influence on the gas consumption and the temperature distribution of ullage. The helium consumption for pressurization at a small flow rate is less than that at a high flow rate. For example, when the drainage flow is 10 L/s, the helium consumption can be reduced by 20% compared with that at 40 L/s. Under all experimental conditions, neither ice due to local supercooling in the tank nor bubbles in the drainage pipeline are observed. The test results verify the feasibility of the proposed scheme, and provide a reference for structural design and working condition regulation of the cryogenic helium pressurization system in rocket.

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    Dynamics Modeling and Validation of Coaxial Lifting Rotors
    HU Jinshuo, HUANG Jianzhe
    2022, 56 (3):  395-402.  doi: 10.16183/j.cnki.jsjtu.2021.044
    Abstract ( 4203 )   HTML ( 108 )   PDF (2567KB) ( 1348 )   Save

    The dynamics model for coaxial lifting rotors can be used to study the controller design and flight simulation for coaxial-rotor aerial vehicles. However, both the computational efficiency and the accuracy should be considered. First, the computational model of the induced velocity of lifting rotor everywhere including the wake region is derived based on adjoint theorem. Then, the finite state dynamics model for coaxial lifting rotors with wake skew considered is developed by extending the finite state inflow model for single rotor. Finally, the equations for calculating the thrust of coaxial lifting rotors in the hover condition are given, and the test is conducted. The results show that the computational complexity of the proposed dynamics model for coaxial lifting rotors is acceptable, and the computational thrusts are almost close to the test results when the rotational speed is within a certain range, which can also reflect the trend of the thrust lost for coaxial lifting rotors.

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