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卷 49 ， 期 5 ， 2025
- 摘要：The low-voltage flexible interconnection technologies based on soft open point (SOP) can realize the power mutual exchange and flexible transfer between station areas, so as to improve the load carrying capability and the accommodation capability of distributed generation. However, due to the periodic change of the power, the current fixed flexible interconnection scheme only has an obvious effect in some periods, resulting in a low utilization rate of flexible interconnection equipment in station areas. In order to solve the above problems, the flexible interconnection concept of mobile soft open point (MSOP) is put forward. Firstly, based on the engineering experience, the challenges faced by the existing low-voltage flexible interconnection technologies are summarized, and the feasibility of the mobile flexible interconnection in the low-voltage station areas is analyzed from the aspects of the construction conditions and the volume, weight and loop closing or opening strategy of SOP equipment. Secondly, the cost-benefit model of the low-voltage mobile flexible interconnection is established, the influence of relocation distance and times on mobile flexible interconnection is analyzed, and the critical conditions of mobile flexible interconnection are discussed. On this basis, the application scenarios of mobile flexible interconnection are summarized. Finally, the potential research directions of MSOP in the field of flexible interconnection of low-voltage distribution network are prospected.关键词：flexible interconnection;low-voltage distribution station area;soft open point;optimal scheduling;cost-benefit analysis;power electronics5|5|0更新时间：2025-06-16
- 摘要：The flexible interconnection device (FID) founded on the power electronic device (PED) integrates functionalities such as active/reactive power independent control, dynamic compensation for reactive power, and fault isolation. It serves as an efficacious resolution for the flexible interconnection power flow among multi-station areas, load rate balancing, and the friendly integration of renewable resources. Despite significant application potential of FIDs, there is a lack of systematic summarization and analysis of its application in different scenarios in terms of networking characteristics, operational characteristics, demand characteristics, and typical functional modes. Firstly, this paper reviews the system architectures, electrical parameters, and operation characteristics of typical flexible interconnection projects in China and other countries. Then, considering characteristics of multi-terminal flexible interconnection in distribution networks and AC/DC interconnected systems with important AC loads/new types of DC loads, this paper offers matched information on typical application scenarios, interconnection network topologies, typical functional modes, electrical network configurations, operation characteristics, and technological requirements. Finally, by integrating the current application status and challenges of flexible interconnection technology in medium-voltage distribution networks, this paper conducts a comprehensive discussion on the development trends of various aspects, including system design and application strategies, key equipment development, and operation control and protection of the system.关键词：distribution network;station area;power electronic device;flexible interconnection;renewable integration;demonstration project6|1|0更新时间：2025-06-16
- 摘要：The temporal-spatial variation of traffic flow leads to changes in the distribution of electric vehicle charging demand, which further affects the electric vehicle hosting capacity in the distribution network. In order to elaborately consider the influence of traffic flow, a calculation method for the electric vehicle hosting capacity in the flexibly interconnected distribution network (FIDN) considering traffic flow is proposed. This method considers the flexible adjustable ability of the soft open point to reduce the adverse effect of large-scale electric vehicle integration on distribution networks. Firstly, based on semi-dynamic traffic flow model, a regulation model for electric vehicles with various integration modes is established. Secondly, considering the regulation measures of electric vehicles under the influence of traffic flow, a calculation model for the electric vehicle hosting capacity in FIDN considering traffic flow is proposed to maximize the number of electric vehicles that can be carried. Then, the model is transformed by the quadratic convex relaxation method, the big-M method and the second-order cone relaxation method. To reduce the relaxation gap, a nested tightening relaxation algorithm is proposed to solve the model. Finally, the validity of the proposed model and algorithm is verified by the test and analysis in the modified standard case and an actual case in Fujian Province of China.关键词：flexible interconnection;distribution network;electric vehicle;hosting capacity;traffic flow;nested tightening relaxation algorithm;soft open point (SOP)4|1|0更新时间：2025-06-16
- 摘要：The wide application of flexible interconnection devices makes the operation of active distribution networks more controllable and flexible. This paper proposes a cooperative planning scheme of soft open points and energy storage devices for balancing the energy distribution in distribution networks with source-load imbalance characteristics in order to improve the economy and reliability of distribution networks. First, considering that the distributed generator output has uncertainty, the K-means method is used to construct a typical-day scenario, based on which a cooperative planning model is established with the minimum annual comprehensive cost as the objective function. Then, the original nonlinear nonconvex model is transformed into a mixed-integer second-order cone planning model by the big-M method and second-order cone relaxation techniques, and a two-stage distributionally robust model with integrated paradigms is used to find the planning scheme that can obtain the lowest operating cost under the probability distribution in the worst scenario in order to improve the robustness of the planning model. Finally, the feasibility of the proposed planning model is verified through the case with two source-load imbalanced IEEE 33-bus active distribution networks.关键词：soft open point;energy storage;distribution network;imbalance;planning;flexible interconnection9|1|0更新时间：2025-06-16
- 摘要：In the flexibly interconnected distribution network based on soft open point (SOP), the sensitivity and reliability of over-current protection cannot meet the requirements due to the characteristics of weak infeed and nonlinear regulation of power electronic equipment. Therefore, based on the idea of detective protection, a single power supply system excited by the dual-frequency detection signals injected by SOP is established, and the fault distance solution equation including fault distance, transition resistance and parameters of the opposite-end system is proposed. A detective phase-to-phase distance protection for flexibly interconnected distribution network is designed by setting the operation delay based on the fault distance and implementing coordination with the inverse time operation strategy. Simulation verification is carried out based on PSCAD, and the protection device prototype is developed. The simulation and hardware-in-the-loop test results prove the effectiveness of the proposed scheme. Compared with the traditional protection principle, the proposed protection scheme is not affected by the characteristic of weak infeed and overcomes the effects of current infeed and draining caused by the opposite-end system and branch lines during the fault through the transition resistance.关键词：flexible interconnected distribution network;soft open point;short circuit;dual-frequency signal injection;distance protection;inverse time7|4|0更新时间：2025-06-16
Key Technologies of Smart Distribution Network Based on Flexible Interconnection
- 摘要：Utilizing renewable energy sources such as wind and photovoltaic to identify cost-effective decarbonization pathways for coastal receiving-end power systems is one of the core challenges in achieving the goals of “carbon emission peak and carbon neutrality” of China. By analyzing the techno-economic differences between hydrogen-ammonia storage and existing energy storage technologies (such as electrochemical and compressed air energy storage), a multi-year expansion planning model for power systems incorporating cofiring coupled hydrogen-ammonia energy storage under temporal decarbonization constraints is established, and the techno-economic feasibility of achieving low-cost decarbonization within the power system is explored. The actual data are selected from Guangdong power grid of China for case study. The results demonstrate that, under increasingly stringent carbon reduction constraints, it is necessary to progressively achieve decarbonization targets through technical pathways, such as the newly added wind and photovoltaic storage, the transition from coal to gas in thermal power planning modes, and the newly added hydrogen-ammonia energy storage (including hydrogen cofiring in gas turbines, ammonia cofiring in coal-fired plants, and ammonia decomposition). Compared with a decarbonization mode relying solely on lithium-ion battery peak shaving, the introduction of cofiring coupled hydrogen-ammonia energy storage technology can avoid overloading excessive wind and photovoltaic storage capacity, thus significantly reducing the wind and photovoltaic curtailment rates. This approach not only achieves intensive resource utilization, but also further reduces the decarbonization cost of hydrogen-ammonia energy storage through the reuse of existing thermal power generation infrastructure. Therefore, the use of hydrogen-ammonia energy storage technology for power system decarbonization presents a scalable and economically feasible decarbonization pathway.关键词：receiving-end power system;decarbonization;energy storage;hydrogen cofiring in gas power generation;ammonia cofiring in thermal power generation;expansion planning;levelized cost of carbon reduction4|4|0更新时间：2025-06-16
- 摘要：Aiming at the participation of multiple integrated energy systems (IESs) in the carbon emission trading (CET) and green certificate trading (GCT) markets, a two-stage mixed-game win-win strategy for IESs considering multi-stage utilization of carbon emission is proposed. A multi-stage carbon emission management strategy is constructed including carbon capture and storage, carbon transfer and utilization, cascaded carbon trading, and green certificate-carbon offset mechanisms. Meanwhile, considering the difference in energy demand and trading strategies among different IESs, an IES trading method based on Stackelberg game-asymmetric Nash cooperative game is proposed. The trading between microgrid operator (MGO) and IESs is a Stackelberg game, and the energy sharing and multi-stage utilization of carbon emissions are realized through asymmetric Nash cooperative game among IESs. Finally, a certain industrial park is taken as a case for verification. The results show that the multi-stage utilization mechanism of carbon emissions among IESs can significantly reduce the carbon emission cost of each IES, improve the flexibility of system operation, and the differential pricing of MGO based on the energy consumption demand of different IESs can increase the revenue of MGO. The IES alliance determines energy sharing prices through asymmetric Nash bargaining to reduce the dependence on MGO and maximize the alliance benefits.关键词：integrated energy system;carbon emission;multi-stage utilization;energy sharing;mixed game;carbon emission trading market;green certificate trading market4|1|0更新时间：2025-06-16
- 摘要：The coordinated dispatch of multi-park integrated energy systems is a crucial means to achieve energy complementarity between parks and improve resource allocation efficiency. Since different parks usually belong to different interest entities, distributed dispatch methods are used to determine multi-park coordinated dispatch schemes. However, the marginal information exchange in the iterative process of distributed dispatch poses a risk of privacy leakage of energy generation/consumption parameters, which limits the enthusiasm of parks to participate in coordinated dispatch. To address this issue, this paper proposes a differential privacy based distributed dispatch method for multi-park integrated energy systems. By adding Laplace disturbance, the method addresses the privacy leakage problem during multiple iterations. Subsequently, a disturbance attenuation algorithm adapted to distributed dispatch is proposed to enhance the convergence of the method. Finally, case studies verify the effectiveness of the proposed method, and the changes in total operating costs of each park with differential privacy are analyzed.关键词：privacy preserving;differential privacy;integrated energy system;distributed dispatch;disturbance attenuation4|2|0更新时间：2025-06-16
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Multi-timescale Resilience Enhancement Method for Integrated Energy System Under Earthquake Disaster
摘要：Earthquake disasters have the characteristics of low predictability and wide impact. In low magnitude or non-epicenter areas, although ground vibrations do not cause building collapse or casualties, they may damage overhead power lines and underground pipelines, and have a significant impact on energy supply systems. Therefore, this paper proposes a multi-timescale resilience enhancement method for the electricity-gas-heat integrated energy system, which includes pre-earthquake planning and emergency response plan formulation, as well as preemptive seismic wave propagation time difference during disasters to complete load forwarding in advance. Firstly, this paper establishes a grid-based fault probability model for the integrated energy system affected by earthquakes. Secondly, this paper proposes a dual-loop optimal load reduction model for integrated energy systems within a decoupling framework. Considering the load satisfaction of building thermal inertia, this paper proposes resilience assessment and multi-timescale resilience improvement methods. Finally, The effectiveness of the method is verified by simulation cases.关键词：integrated energy system;resilience;multi-timescale;optimal load reduction;emergency response5|0|0更新时间：2025-06-16 - 摘要：The islanded AC/DC hybrid microgrid cluster often adopts the proportional allocation method for the sub-microgrid power, which poses a risk of frequency and DC bus voltage limit violations under heavy loads. To solve the problem, a hierarchical coordinated control strategy is proposed. Firstly, a hierarchical control structure is constructed. Secondly, a power allocation method for interlinking converters based on sub-microgrid limit power point clamping is proposed in the microgrid cluster control layer. When heavy loads are connected, this method limits the power of the sub-microgrid with the risk of limit violation to the threshold and ensures that the steady-state frequency and voltage are within limits. Thirdly, a sub-microgrid instantaneous power control method based on differential feedforward compensation of frequency and voltage is designed, which can further ensure that the dynamic frequency and voltage are within limits. Based on this, the small-signal model of the system is built to analyze the impact of critical parameters on the stability, and the design process of critical parameters is given. Finally, simulation results under multiple operation conditions verify the effectiveness and superiority of the proposed method.关键词：AC/DC hybrid microgrid;frequency limit violation risk;voltage limit violation risk;hierarchical coordinated control;power distribution;small-signal model5|1|0更新时间：2025-06-16
- 摘要：Permanent magnet synchronous wind turbines can be modified to serve as black-start power sources, enhancing grid recovery capabilities in extreme outage scenarios. To address the problem of insufficient grid-forming support capacity of wind turbines under wind speed fluctuation conditions during black-start load shocks, this paper proposes a permanent magnet synchronous wind turbine-energy storage combined power source, along with a coordinated control method. First, on the electromechanical transient time scale, the method improves the ability of wind turbines to track load power changes by capturing wind power based on the black-start load power prediction. Then, on the electromagnetic transient time scale, a coordinated control method for the inverter combining wind turbine with energy storage is proposed to enhance the response capability of the wind turbine-energy storage combined power source to load shocks. Finally, a black-start and load connection method based on the inertia and kinetic energy of the wind turbine is presented. This involves connecting to the grid and load at high rotational speeds of the wind turbine, utilizing the released kinetic energy to complete the black-start. Simulation results show that, compared with the conventional black-start method for wind power, the proposed method can significantly improve the stability of wind power systems against load shocks under wind speed fluctuation conditions, while reducing the power and capacity requirements for energy storage.关键词：wind turbine-energy storage combined power source;inertial;grid-forming control;black-start;wind turbine6|2|0更新时间：2025-06-16
- 摘要：The random volatility of renewable energy has made the influence of automatic generation control (AGC) actions of units on the system operation increasingly prominent. The existing stochastic optimal economic dispatch methods are difficult to account for the actual response actions of AGC units on fine-grained timescales during the dispatch periods, seriously threatening the safe operation of the power grid. Therefore, this paper proposes a chance-constrained economic dispatch method explicitly considering response actions of AGC units on fine-grained timescales. First, the response model of AGC units on fine-grained timescales considering the uncertainty of net load is constructed. Based on the actual response strategy of AGC, a response mode of AGC units to net load fluctuations and their uncertainties is constructed under the chance-constrained framework, achieving accurate modeling of AGC unit response actions on fine-grained timescales. Then,a chance-constrained economic dispatch method embedded with AGC unit response models on fine-grained timescales is proposed, which considers the response actions of AGC units on fine-grained timescales in the chance-constrained economic dispatch model. Finally, the proposed chance-constrained economic dispatch model is reformulated in an analytical form, achieving an explicit characterization of the response actions of AGC units on fine-grained timescales. The proposed modeling method is not limited to the chance-constrained optimization and can also be applied to stochastic optimization methods such as multi-scenario and robust optimization. The case analysis shows that the proposed method provides a more economical and secure dispatch scheme compared with existing chance-constrained economic dispatch methods.关键词：uncertainty;frequency regulation reserve capacity;chance constraint;economic dispatch;fine-grained timescale;automatic generation control (AGC)6|0|0更新时间：2025-06-16
- 摘要：In the background of electricity marketization, the open electricity market is affected by demand-side load, renewable energy output and coupling relationship between markets, and its electricity price fluctuation becomes more and more intense and difficult to forecast. In order to rationally select the comprehensive factors affecting the fluctuation of electricity price and reduce the negative impact of the instability and strong fluctuation of the original electricity price series on the electricity price forecasting, this paper proposes a double-branch day-ahead electricity price forecasting method based on the combination of dual-mode decomposition, Inception and attention mechanism. First, the maximum information coefficient screening and the influence factors with high correlation with the day-ahead electricity price are combined as the input of the model correlation variable feature matrix. Then, through variational mode decomposition and swarm decomposition, the original electricity price series are decomposed into multiple subseries that can better reflect the electricity price fluctuation law. The subseries obtained by different decomposition methods are sorted from high frequency to low frequency, and then the multi-scale electricity price component matrix is constructed as the input of the electricity price branch of the model to improve the regularity and information richness of the modal components. Finally, the improved Inception module is combined with parallel multidimensional attention (PMDA) and self-attention mechanism respectively to build a double-branch day-ahead electricity price forecasting model to extract and fuse important features of input data from different branches and output the electricity price forcasting results for the next day. By using the historical data of Nordic electricity market as a case for verification, and comparing with the traditional attention mechanism, the experimental results show that the proposed PMDA mechanism can extract important features of electricity price series more effectively, so as to improve the forecasting accuracy of day-ahead electricity price.关键词：electricity price forecasting;attention;maximal information coefficient;Inception network;electricity market8|6|0更新时间：2025-06-16
Basic Research
- 摘要：The major power outages abroad show that a large number of different renewable energy sources may experience coexistence scenarios of low voltage ride-through (LVRT) and off-grid after disturbance, presenting complex nonlinear dynamic changes in the overall power impact on the system, and making transient frequency trajectory prediction increasingly difficult. The existing frequency trajectory prediction and analysis methods usually only consider single disturbance such as LVRT or off-grid, and lack practical and feasible engineering application schemes, making it difficult to carry out early warning or pre-control for frequency insecure scenarios. Therefore, this paper firstly analyzes the mechanism of the difference in active power restoration caused by the distribution characteristics of wind power output during the LVRT process and its impact on the system power shock. Secondly, considering various forms of power disturbances such as step and non-step, a power grid frequency response model that takes into account the coexistence of LVRT complex restoration and off-grid of wind power is proposed. Then, an engineering application scheme based on “offline grading modeling, online fast prediction, and critical additional verification” is proposed. Finally, the effectiveness and practicality of the proposed model and method are verified through the New England 10-machine 39-bus test system and an actual power grid case simulation.关键词：high proportion of renewable energy;low voltage ride-through;off-grid;transient frequency;prediction5|1|0更新时间：2025-06-16
- 摘要：The integration of a large number of distributed power generation units results in weakening power grid strength, which in turn causes harmonic resonance of output current of photovoltaic cluster, threatening the safe and stable operation of power system. Therefore, considering the constraint of harmonic resonance, based on the source and grid impedance aggregation model and stability index of the system, the objective function of the optimal stability margin for the system under a certain grid-connected power of renewable energy is constructed. The Newton numerical iteration is integrated into the solving process of Lagrange condition extremum to achieve rapid adjustment of impedance sensitivity towards consistency. Aiming at the application scenarios of constant power and the allocation of maximum grid-connected power, an optimal allocation method of grid-connected power based on Newton iterative sensitivity collaboration is proposed. Compared with conventional cluster power allocation methods and similar optimal allocation methods, the proposed optimal power allocation method has high solving efficiency and low computing power requirements. Finally, an IEEE 33-bus case is built on the real-time hardware-in-the-loop digital simulation system to validate the proposed method.关键词：distributed power generation;renewable energy integration;power allocation;oscillation stability;sensitivity coordination;Newton numerical iteration5|1|0更新时间：2025-06-16
- 摘要：When multiple inverters are connected to the power grid, the harmonic interaction among inverters and the harmonic interaction between the inverters and the power grid can significantly impact both the inverters and the overall operation of the power grid. Aiming at the difficulty in identifying and evaluating the effects of interactions in multi-machine systems, this paper first establishes a small-signal current model for a single inverter considering specified current disturbances. The model is extended to the multi-inverter parallel system. Meanwhile, the concepts of the mutual-interaction factor and the self-interaction factor of harmonic admittance are proposed to categorize the system disturbances into mutual disturbances and self-disturbances. On this basis, the peak of the interaction factor is analyzed. Using the derived peak criterion, the quantization conditions for harmonic amplification resulting from the system harmonic interactions are obtained, and an exclusion zone to mitigate harmonic interaction amplification is proposed. Finally, this paper discusses the harmonic interaction rules of the multi-inverter parallel system in the influences of current control parameters, phase-locked loop parameters, inverter damping strategies, power grid impedance parameters, and the number of parallel inverters through case analysis. The correctness and effectiveness of the proposed analytical approach are validated.关键词：grid-connected inverter;multi-machine system;harmonic interaction;harmonic amplification;impedance analysis method;interaction factor;peak criterion;stable exclusion zone5|3|0更新时间：2025-06-16
- 摘要：The peak shaving resource at demand side is an important part of peak shaving resources in new power systems. However, due to the internal and external factors such as the uncertainty of user behaviors and abnormal equipment status, some loads often fail to respond reliably. Aiming at the low response reliability of demand-side resources in industrial parks during the actual peak shaving, a precise peak shaving strategy at demand side is proposed considering load response reliability and aggregator scheduling economy. Firstly, a regulation model is established for the direct control of central air conditioning load and industrial load, and the relevant factors that affect its response reliability are analyzed by combining diversified characteristic loads. Secondly, the load response reliability index is defined to quantitatively characterize the influence degree of internal and external factors on load response reliability. Together with load regulation cost, it is used as a decision variable for load aggregation, and the peak shaving response optimization scheme at demand side is solved through iterative algorithms. Finally, based on the central air conditioning load data from the Open Energy Data Initiative (OEDI) dataset of America and the load data from an industrial park in Hubei Province, China, the proposed precise peak shaving strategy is compared and simulated with the economic-only peak shaving strategy by using economic incentives as the only means, and the total scheduling cost and actual response ratio of load aggregators are analyzed as evaluation indicators to verify the effectiveness of the proposed strategy.关键词：peak shaving;demand response;reliability;economy;indicator system;multi-objective optimization;air conditioning load;industrial load5|5|0更新时间：2025-06-16
- 摘要：Dynamic line rating (DLR), as an effective technique to alleviate the intermittent network congestion, can significantly increase the operation benefits of power systems. However, since congestion management is inherently embedded within the solution process of security constrained economic dispatch (SCED), the intricate details of this process are not easy to obtain. Consequently, it is difficult for market operators to accurately analyze the economic benefits of DLR and formulate DLR plans combining economic efficiency with safety. To address this issue, this paper proposes a traceback method for congestion management process with quantitative analysis of contributing factors for the single-branch congestion scenarios. By comprehensively dissecting and analyzing the congestion management process within the framework of SCED, a linkage relationship among DLR plans, congestion management, and locational marginal price is established. On this basis, a benefit calculation method of DLR that incorporates the traceback of congestion management process is further proposed. Finally, through case analysis, the effectiveness of the proposed traceback method and the feasibility of the benefit calculation method of DLR are validated.关键词：electricity market;economic dispatch;dynamic line rating;transmission capacity;congestion management;traceback5|1|0更新时间：2025-06-16
Application Research
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