Loading...

Table of Content

    28 December 2023, Volume 57 Issue 12 Previous Issue    Next Issue
    New Type Power System and the Integrated Energy
    Wind Power Scenario Generation Method and Application Based on Spatiotemporal Covariance Function
    PENG Xinghao, LI Yanting
    2023, 57 (12):  1531-1542.  doi: 10.16183/j.cnki.jsjtu.2022.180
    Abstract ( 368 )   HTML ( 279 )   PDF (8178KB) ( 251 )   Save

    Wind power generation is different from traditional power generation in which wind power output is highly stochastic and spatio-temporally dependent. In the optimal scheduling problem of wind power grid-connected power system, ensuring the optimal execution of power scheduling in different wind power scenarios is the key of the decision-making problem. Therefore, high quality wind power scenario generation is of great importance. The spatiotemporal correlation of the output power of wind power plants are characterized based on Gaussian stochastic process and spatiotemporal covariance function, and the joint probability distribution is established by the Pair Copula model, and specific scenarios are implemented by the method of empirical probability inverse transformation. A variety of scene metrics of the generated scene are generated, which verifies the superiority of the generated scene. Finally, based on the modified IEEE 6-bus system, a mixed integer programming model for the unit output of the power system is established to solve the problems in different scenarios and verify the economic advantages of the scenario generation method in the dispatching problem of wind power grid connection.

    Figures and Tables | References | Related Articles | Metrics
    Business Models for Large-Scale Energy Storage Systems to Participate in Electricity Spot Market
    LI Qian, JIANG Xin, ZHANG Junzhao, DUAN Shijie, JIN Yang
    2023, 57 (12):  1543-1558.  doi: 10.16183/j.cnki.jsjtu.2022.187
    Abstract ( 390 )   HTML ( 270 )   PDF (9620KB) ( 310 )   Save

    In this paper, large-scale energy storage system(ESS) is taken as the research object to conduct study of business models on the participation of ESS in electricity spot market with liberalization. First, based on the typical market clearing mechanism at home and abroad, the clearing method, clearing calculation process and so on in day-ahead market and real-time balance market are analyzed, and a joint clearing mechanism suitable for large-scale ESS to participate in the spot market is proposed, including bidding method, billing method and clearing method, etc. Then, in order to fully explore the market value and other added value of large-scale ESS, to enhance cluster effect and to solve the problem of idle ESS capacity, business models suitable for large-scale ESS to participate in the spot market are proposed, including independent (single investment entity, single service model), alliance (diversified investment entities, single service model), and shared (diversified investment entities, diversified service models) models. The game relationship in the market transaction chain is analyzed, of which the electric energy value, the ancillary service value, and other added value are quantified. On this basis, a bilevel clearing model paradigm for ESS to participate in the spot joint market of different business models is constructed based on the master-slave game. In the upper-level model, large-scale ESS is the leader to participate in market competition with the goal of maximizing profits, while the dispatching and trading center in the lower-level model are followers to jointly clear the market with the goal of maximizing social welfare. Finally, the validity and feasibility of the proposed business models are verified by taking typical transaction scenarios as examples based on the improved IEEE30 node system.

    Figures and Tables | References | Related Articles | Metrics
    Coordinated Scheduling of Multiple Buildings with Electric-Hydrogen Complementary Considering Frequency Stability Constraints
    FAN Hong, WANG Lankun, XING Mengqing, TIAN Shuxin, YU Weinan
    2023, 57 (12):  1559-1570.  doi: 10.16183/j.cnki.jsjtu.2022.380
    Abstract ( 200 )   HTML ( 17 )   PDF (2948KB) ( 139 )   Save

    In order to achieve the dual carbon goal of “carbon peak and carbon neutrality”, it is of great significance to promote the electric and hydrogen complementary integrated energy system. However, with the gradual increase of the penetration rate of renewable energy, the inertia level of the system decreases, and the frequency security is threatened. Aimed at the problem that the traditional optimization scheduling method cannot guarantee the frequency stability of the system, a coordinated optimization scheduling method of electric-hydrogen complementary multiple buildings considering the frequency stability constraint is proposed. First, the architecture of the electric-hydrogen integrated energy system with the building as the ground floor unit is established, and the renewable energy generator sets in the system are controlled by the virtual synchronous generator technology to improve the inertia level of the system. Then, aimed at minimizing the total operating cost of the system in the scheduling period, and considering the inertia requirements of the system in different operation modes of grid-connected and islanding, an optimal scheduling model considering the system frequency stability constraint is established. Finally, an example is given to verify the effectiveness, economy, and environmental protection of the proposed method for frequency stability of the system.

    Figures and Tables | References | Related Articles | Metrics
    Low Carbon Economic Dispatch of Virtual Power Plants Considering Ladder-Type Carbon Trading in Multiple Uncertainties
    PENG Sijia, XING Haijun, CHENG Mingyang
    2023, 57 (12):  1571-1582.  doi: 10.16183/j.cnki.jsjtu.2022.185
    Abstract ( 237 )   HTML ( 18 )   PDF (2747KB) ( 182 )   Save

    Virtual power plant (VPP) with a carbon capture system provides a new path to improve energy efficiency and achieve the target of carbon peaking and carbon neutrality. At the same time, flexible coordination of multiple uncertainties in the VPP system is a key premise to realize low-carbon operation of the system. A low-carbon economic dispatch model of VPP considering ladder-type carbon trading in multiple uncertainties is proposed. The carbon capture system and demand response are modeled, and a carbon trading mechanism is introduced into the optimal dispatch model to build a ladder-type carbon trading cost model to restrict system carbon emissions. A variety of uncertain factors in VPP is modeled, including wind power generation, photovoltaic, load and electric vehicle, and a low carbon economic dispatch model of VPP is established considering opportunity constraints. The uncertainty of electric vehicles is dealt with by using adjustable robust optimization. Based on the sequence operation theory, the uncertain model with opportunity constraints is transformed into a mixed integer linear programming model. The decision optimization technology CPLEX solution is used to verify the effectiveness of the proposed model in an actual VPP example.

    Figures and Tables | References | Related Articles | Metrics
    Multi-Time-Space Scale Optimal Dispatch of Integrated Energy in Micro-Energy Grid Considering Demand Response
    QIN Wenping, YANG Jingsi, JING Xiang, YAO Hongmin, LI Xiaozhou, ZHANG Xinzhe
    2023, 57 (12):  1583-1596.  doi: 10.16183/j.cnki.jsjtu.2022.177
    Abstract ( 233 )   HTML ( 13 )   PDF (3866KB) ( 175 )   Save

    The operation of the integrated energy system is one of the hot spots in the current energy research field. With the reform of the energy field mechanism, the integrated energy system with multi-micro-energy grids poses great challenges to the operation of the power grid. Aimed at the economic and operational problems caused by the integration of multi-micro-energy grid integrated energy systems into the upper distribution network, a multi-temporal and spatial scale optimization operation strategy for integrated energy of micro-energy grid considering demand response is proposed. Moreover, a multi-dimensional energy supply and demand balance model from the perspective of energy is constructed. Furthermore, a multi-time-space scale operation model with upper, middle, and lower layers of collaborative optimization is established. The upper layer adopts day-ahead scheduling, the middle layer adopts intraday scheduling, and the lower layer adopts real-time scheduling with replaceable, transferable, and curtailable loads for demand response optimization. Calculation examples show that this strategy can realize the co-ordination and complementation of multi-dimensional energy sources, realize the coordinated operation of multiple energy sources at different time and space scales, and improve the economy of system operation.

    Figures and Tables | References | Related Articles | Metrics
    Generating Mechanism and Suppression of Impulse Voltage on Secondary Bus of Marine Electromagnetic Transmitter
    TAO Haijun, DU Changshun, ZHANG Jinsheng, ZHENG Zheng
    2023, 57 (12):  1597-1608.  doi: 10.16183/j.cnki.jsjtu.2022.403
    Abstract ( 157 )   HTML ( 8 )   PDF (10479KB) ( 126 )   Save

    Electromagnetic detection is the main method of marine oil and gas resources exploration, and marine electromagnetic transmitter is the key equipment of marine electromagnetic detection system. At present, when the underwater towed body of the marine electromagnetic transmitter operates for a long time, the switch devices will be damaged. First, the commutation process of the transmitting bridge with unidirectional controlled-source circuit is analyzed. It is found that the feedback energy of the transmitting dipole parasitic inductor makes the secondary bus generate impulse voltage, which increases the voltage stress of the switch devices. Then, the operating mode of bidirectional controllable source circuit is analyzed, and a dual variable decoupling control strategy is proposed. Based on the model established at the front and back of the transformer, the original coupling nonlinear system is globally linearized into two single input single output systems, so as to obtain the functional relationship of the sliding mode controller. The simulation and experimental results show that the designed controllable source circuit can significantly reduce the impulse voltage of bus capacitor and the voltage stress of switch device, and improve the dynamic performance and efficiency of the system.

    Figures and Tables | References | Related Articles | Metrics
    Naval Architecture, Ocean and Civil Engineering
    Numerical Analysis of Force of Fluidized Solidified Slurry in Pumping for Scour Repair on Offshore Pile Foundation
    LI Ruyu, WU Xiaoni, CHEN Jinjian, JIANG Haili, WANG Huili
    2023, 57 (12):  1609-1618.  doi: 10.16183/j.cnki.jsjtu.2022.280
    Abstract ( 211 )   HTML ( 9 )   PDF (6317KB) ( 197 )   Save

    As a novel scour protection measure, the fluidized solidified slurry is pumped into the developed scour holes around the pile foundation for scour repair as the fluidized material solidifies gradually. In the process of pumping operation, the fluidized solidified slurry will have a negative effect on the pile. However, there is still a lack of comprehensive study on the force acting on the pile in this process. The CFD model is adopted to simulate the flow and diffusion of the solidified slurry pumped into the scour pit around the monopile. The effects of pumping velocity, current velocity, and material property of solidified slurry on the force acting on the pile are systematically investigated, of which, current velocity is the most sensitive factor. A simplified analysis method for force of fluidized solidified slurry acting on the monopile is proposed, providing basis for the design and construction of the pumping operation.

    Figures and Tables | References | Related Articles | Metrics
    Web Crippling Capacity of Cold-Formed Stainless Steel SHS and RHS
    ZHAN Kejiang, LI Haiting, WANG Miao, ZHOU Feng, ZHAO Jincheng
    2023, 57 (12):  1619-1630.  doi: 10.16183/j.cnki.jsjtu.2022.291
    Abstract ( 231 )   HTML ( 15 )   PDF (6599KB) ( 185 )   Save

    This paper investigates the ultimate capacities of domestic cold-formed stainless steel square and rectangular hollow sections (SHS and RHS) undergoing web crippling. The finite element (FE) software Abaqus was employed during the investigation. It verifies the validity of FE models against experimental results available in the literature and performs an extensive parametric study comprised of 224 FE analyses to obtain the web crippling capacities of cold-formed stainless steel SHS and RHS, considering various materials, cross-sectional dimensions, bearing lengths and loading conditions in the parametric study. Based on the obtained FE results, the applicability of existing web crippling design provisions to domestic cold-formed stainless steel SHS and RHS is evaluated. The results indicate that the technical code of cold-formed steel structures (exposure draft) cannot be used for the studied cold-formed stainless steel SHS and RHS. On the other hand, it is shown that the American Specification SEI/ASCE 8-22 and proposed direct strength method (DSM) can lead to safe and accurate design predictions. Therefore, the SEI/ASCE 8-22 and DSM can be used to predict the capacities of domestic cold-formed stainless steel SHS and RHS undergoing web crippling.

    Figures and Tables | References | Related Articles | Metrics
    Two Dimensional Nonlinear Consolidation Analysis of Saturated Soft Soil Around Tunnel
    HU Anfeng, GONG Zhaoqi, XIAO Zhirong, CHEN Yuan
    2023, 57 (12):  1631-1638.  doi: 10.16183/j.cnki.jsjtu.2022.228
    Abstract ( 135 )   HTML ( 9 )   PDF (2636KB) ( 323 )   Save

    Considering the nonlinear changes of compressibility and permeability of soft soil around the tunnel, a two-dimensional nonlinear seepage consolidation control equation is established, which is solved by an alternating implicit difference method, and the development law of the average degree of consolidation with time under the three conditions of complete permeability, complete impermeability, and semi permeability of the tunnel is obtained. By comparing the degenerate solution with the existing analytical solution, the correctness of the difference solution is verified. In addition, the effects of compression index Cc and permeability index Ck on the consolidation degree of soft soil around the tunnel are analyzed. The results show that the permeability of tunnel is an important factor affecting the development and change of consolidation degree. The influence of compression index Cc on the development of degree of consolidation is less than that of permeability index Ck. Seepage consolidation will change the effective stress field of the soil around the tunnel, and the average degree of consolidation decreases with the increase of permeability index Ck. If the nonlinearity of soil is not considered, there will be a large error in the calculation of degree of consolidation.

    Figures and Tables | References | Related Articles | Metrics
    Observed Environment Response Caused by Construction of Double-Line Parallel Pipe Jacking Crossing over Metro Shield Tunnels
    YING Hongwei, YAO Yan, WANG Kuihua, ZHANG Changju
    2023, 57 (12):  1639-1647.  doi: 10.16183/j.cnki.jsjtu.2022.290
    Abstract ( 252 )   HTML ( 4 )   PDF (2687KB) ( 196 )   Save

    Based on the field measured data of a double-line parallel power pipe jacking upper span subway shield tunnel, the environmental impact of a short-distance double-line pipe jacking in sandy silt stratum in the process of crossing over the existing subway tunnel was analyzed in detail, including the transverse surface settlement distribution, the development of settlement with time, and the floating of subway tunnels. The results show that the horizontal surface settlement curve of single pipe jacking presents a “V” shape, while the horizontal surface settlement curve of double line pipe jacking is an asymmetric “W” shape. The settlement of ground surface above the axis of the later pipe jacking is larger than that of the first pipe jacking. During the construction of the later pipe jacking, the settlement above the axis of the first pipe jacking is also obvious. The Peck formula has a good applicability in predicting surface settlement curve caused by pipe-jacking construction. For single-line pipe-jacking, the width parameter of settlement trough is 0.79, and the ground loss ratio is 1.6%. For double-line pipe jacking, the width parameter of settlement trough of the first and later pipe jacking are 0.74 and 0.58 respectively, and the former is 1.28 times of the latter. The soil loss ratio of the first and the second pipe jacking are 2.41% and 3.11% respectively, and the latter is 1.29 times of the former. Pipe jacking causes the vertical displacement distribution curve of the “W” shape in the longitudinal direction of the underlying subway tunnel. There is a lag in the up-floating of the tunnel after the completion of pipe jacking crossing. The longitudinal influence range of the parallel pipe jacking construction on the subway shield tunnel is about 4~6 times the pipe jacking diameter. The instantaneous settlement generated by the later pipe jacking across the monitoring section is greater than that generated by the first pipe jacking. The permeability of the undisturbed soil is reduced when the silty soil above the tunnel is pre-reinforced by the metro jet system (MJS). The ground settlement will continue for a period of time after the pipe jacking crossing. The exponential function can be used to describe the development of the settlement with time after the instantaneous settlement occurs.

    Figures and Tables | References | Related Articles | Metrics
    Time-Frequency Analysis of Noisy Vibration Signal Based on Improved Hilbert-Huang Transform
    SUN Miao, YANG Junkai, WU Li
    2023, 57 (12):  1648-1656.  doi: 10.16183/j.cnki.jsjtu.2022.255
    Abstract ( 257 )   HTML ( 10 )   PDF (4047KB) ( 282 )   Save

    Aimed at the phenomenon of modal confusion and lack of practical significance of instantaneous frequency caused by Hilbert-Huang transform (HHT) noisy vibration signal time-frequency analysis, complete ensemble empirical mode decomposition with adaptive noise (CEEMDAN) is obtained by improving empirical mode decomposition (EMD), and in combination with multiscale permutation entropy (MPE) to suppress EMD modal confusion. At the same time, improved normalized Hilbert transform(INHT) is obtained by improving Hilbert transform, and finally the CEEMDAN·MPE-INHT time-frequency analysis algorithm is formed. In order to verify the accuracy of time-frequency analysis of CEEMDAN·MPE-INHT noisy vibration signals, a comparative study of time-frequency analysis of EMD-HT, EEMD-NHT, CEEMDAN-INHT and CEEMDAN·MPE-INHT noisy simulation vibration signals is conducted. The results show that CEEMDAN can control low frequency noise; MPE can suppress high frequency noise; INHT can make Hilbert transform not constrained by Bedrosian theorem. Finally, CEEMDAN·MPE-INHT algorithm is applied to the time-frequency analysis of noisy vibration signals in practical engineering. The time spectrum of intrinsic mode function (IMF) decomposed by CEEMDAN·MPE after INHT processing has a high resolution in time domain and frequency domain, which can improve the extraction accuracy of time-frequency characteristic parameters and help control the harm of vibration signals.

    Figures and Tables | References | Related Articles | Metrics