最新刊期
卷 50 ， 期 20 ， 2026
- 摘要：With the large-scale integration of distributed power generation and loads into the power grid, the energy internet is increasingly exposed to cross-domain security risks. A quantitative analysis of these potential risks is essential for identifying critical points in the security defense framework. To this end, this paper first reviews the forms of cross-domain attacks in the energy internet and their mechanisms of power system disruption, highlighting the distribution and evolution characteristics of such risks. Based on this, it examines the formation and aggregation mechanisms of cross-domain distributed disturbances, as well as how factors such as observation conditions and available communication capacity influence attack effectiveness. A heterogeneous propagation dynamics model and a stochastic dynamics model are then developed to characterize the dynamic evolution of disturbances and to quantify attack threats marked by both evolutionary and stochastic features. Finally, the paper discusses key technical challenges and research prospects in quantifying cross-domain cyber-physical security risks and providing a reference for the future research of proactive defense systems in the energy internet.关键词：Energy Internet;cross-domain attack;security risk;distributed power generation;heterogeneous propagation dynamics;stochastic dynamics16|1|0更新时间：2026-10-22
- 摘要：As an important inorganic chemical product, ammonia is undergoing a profound low-carbon transition across its industrial value chain from “grey ammonia” to “green ammonia”. Based on the water-energy-carbon (WEC) linkage relationship, this paper provides a comprehensive review and prospects of electricity for power-to-hydrogen-to-ammonia (P2H2A) coupling technologies. Firstly, the fundamental characteristics of P2H2A coupling technologies are elucidated. The technological pathways, modeling approaches, system configurations, and engineering practices associated with key multi-timescale coordination processes, including water electrolysis for hydrogen production, ammonia synthesis, downstream chemical production, and P2H2A coupling systems, are systematically reviewed. The coupled feedback relationships among water consumption for hydrogen production, regional water-resource carrying capacity, energy utilization, and carbon emission reduction are also revealed. Subsequently, recent research advances in P2H2A coupling technologies are reviewed, with particular emphasis on the analysis of system planning, cross-timescale operational regulation, market mechanisms, and WEC synergies. Finally, the development trends and prospects of P2H2A coupling technologies are discussed. It is concluded that technological advancement, policy support, and regional collaboration are key factors in promoting their large-scale deployment.关键词：water-energy-carbon;power-to-hydrogen-to-ammonia (P2H2A);green ammonia;low-carbon transition;carbon emission reduction;multi-timescale coordination10|0|0更新时间：2026-10-22
Review·Perspective
- 摘要：Park-level integrated energy systems (PIESs) contain substantial carbon emission reduction potential in their internal multi-energy loads. At present, the low-carbon regulation of PIESs mainly relies on daily fixed carbon prices. However, the energy consumption behaviors of internal users are closely interacted with carbon emissions, and a fixed carbon price alone cannot capture the temporal differences in carbon attributes of energy consumption or effectively guide users toward low-carbon energy consumption. To address this issue, this paper proposes a carbon-energy coordinated operation method for PIESs considering dynamic internal carbon pricing (DICP). First, a carbon-energy synergistic hub (CESH) model is established to characterize the internal carbon-energy interaction mechanism of PIESs. Then, the CESH model is used to calculate dynamic carbon emission factors of multi-energy loads, quantify the carbon emissions caused by users’ energy consumption during various periods, and map them into internal price signals that vary positively with the emission factors, thereby establishing the DICP model for PIESs. Furthermore, with the objective of minimizing the annual total cost, including the internal carbon cost calculated by DICP, a bi-level low-carbon economic operation optimization model for PIESs is developed, considering carbon-energy balance, equipment operating limits, and carbon trading constraints over the compliance cycle. Case studies show that the proposed method can guide users to reduce energy consumption when DICP is high and increase energy consumption when DICP is low, thereby fully exploiting the carbon emission reduction potential of multi-energy loads in PIESs. Compared with the PIES operation optimization method considering only an external fixed carbon price, the proposed method further reduces operating cost and carbon emissions by 3.23% and 7.22%, respectively.关键词：integrated energy system;carbon-energy coordination;carbon price;carbon trading;carbon emission reduction;carbon emission factor;operation optimization6|0|0更新时间：2026-10-22
- 摘要：In the provincial electric-thermal integrated energy systems in Northern China, with the continuously growing penetration of wind-solar renewable energy, orderly storing the overall surplus renewable energy within a scheduling cycle into electric and thermal energy storage devices for subsequent scheduling cycles has become an increasingly common day-ahead scheduling scenario. Aiming at the problem that existing scheduling models based on curtailment penalty suffer from multiple solutions when applied to multi-energy system scheduling, which fails to guide the orderly and efficient storage of curtailed renewable energy among heterogeneous energy storages, this paper proposes a strategy that converts the end-of-day stored energy of electric and thermal energy storage into equivalent costs according to their utilization value in subsequent days, and deducts such equivalent costs in the objective function of the scheduling model. Through theoretical analysis of six operating conditions of electric-thermal energy storage in non-curtailment and curtailment scenarios, the reasonable value range of conversion coefficients for the equivalent cost of stored energy in electric and thermal energy storage is determined, and the orderly guidance for electric-thermal energy storage during scheduling is realized. Case studies are conducted based on a provincial electric-thermal integrated energy system in Northern China to verify the effectiveness and superiority of the proposed scheduling model.关键词：electric energy storage;thermal energy storage;integrated energy system;renewable energy;coordinated scheduling;scheduling cycle;curtailment penalty10|1|0更新时间：2026-10-22
- 摘要：The large-scale popularization and application of electric vehicles have strengthened the coupling interaction between transportation networks and distribution networks. Advanced autonomous driving technologies have facilitated the adoption of intelligent transportation operation modes relying on vehicle autonomous mobility-on-demand (AMoD) systems, which further increases the operation complexity of transportation-power coupling networks. This paper puts forward an operation model and pricing strategy for transportation-power coupling networks with vehicle AMoD systems. First, an operation framework for transportation-power coupling networks with AMoD systems is proposed, and a bi-level coupled operation model for the transportation-power coupling network considering the interaction influence of controllable and uncontrollable traffic flows is established to describe the operating states of coupling networks. Among them, the upper-level model is a social optimum model covering the distribution network and controllable traffic flows of transportation networks, whereas the lower-level model is a stochastic user equilibrium model centered on the uncontrollable traffic flows of transportation networks. Then, an optimal pricing strategy for transportation-power coupling networks based on the inverse optimization method is designed. It guides the travel of uncontrollable traffic flows via reasonably collecting road congestion charges and charging surcharges to realize the globally optimal operation of coupling networks. Finally, numerical cases verify the effectiveness of vehicle AMoD systems and the proposed pricing strategy in cutting the total operating costs of coupling networks.关键词：electric vehicle;transportation-power coupling network;autonomous mobility-on-demand (AMoD);inverse optimization;operation model;pricing strategy8|0|0更新时间：2026-10-22
- 摘要：Aiming at the temporal mismatching problem between the charging and discharging behaviors of large-scale electric vehicles and the photovoltaic output power, this paper proposes a three-stage optimization strategy for ordered charging and discharging of electric vehicles considering dynamic carbon quota. The strategy establishes a phased guidance mechanism based on the synergy of “carbon-electricity” signals. First, during the midday period of high photovoltaic generation, the dynamic carbon emission factor is used as the core, combined with dynamic weights to guide electric vehicles to accommodate green electricity. Then, during the nighttime peak-load period, based on the discharging priority generated from the first stage results, the discharging optimization is carried out with the grid peak-shaving demand as the main factor. Finally, during the nighttime valley-load period, the dynamically updated charging service charge is introduced to incentivize valley-filling charging behavior. Simulation results demonstrate that the proposed strategy can effectively improve the photovoltaic accommodation rate at different levels of user participation, significantly reduce the total charging cost of users and the peak-valley load difference of the power grid, and validate its feasibility and effectiveness in synergistically promoting the renewable energy accommodation and supporting grid peak shaving and valley filling.关键词：electric vehicle (EV);distribution network;photovoltaic accommodation;peak shaving and valley filling;vehicle to grid (V2G);carbon quota;carbon emission factor;optimization strategy8|0|0更新时间：2026-10-22
- 摘要：Under the high proportion of renewable energy, the penetration of power electronics in weakly interconnected local grids in remote areas continues to increase, while the proportion of conventional power sources declines and disturbance-rejection capability weakens. After a tie-line fault, such grids are prone to splitting into isolated islands, facing risks of power supply guarantee, security and stability. This paper proposes an optimal allocation strategy of grid-forming energy storage (GFES) for fully power-electronics-based weakly interconnected local grids with GFES as the core support, which accommodates both grid-connected and islanded operation states as well as the dual requirements for power supply guarantee and frequency support. Firstly, a chronological production simulation model considering grid-connected status and islanding time is constructed. Secondly, a frequency response equivalent model for the islanded system dominated by GFES is established, and key control parameters are identified and embedded into the chronological production simulation model. The dual requirements of the system on GFES for power supply guarantee and frequency support during islanding are analyzed, and an optimal allocation model for GFES capacity is then formulated, considering both operational adequacy and security in islanded mode. Finally, a case study based on an actual county-level power grid is conducted to verify the effectiveness of the proposed allocation method.关键词：high proportion of renewable energy;local grid;grid-forming energy storage (GFES);frequency response;power supply guarantee;optimal allocation;chronological production simulation10|0|0更新时间：2026-10-22
- 摘要：To enhance the voltage support capability of renewable energy bases, grid codes require that a certain proportion of static var generators (SVGs) should be installed in these bases. However, how SVGs affect the static voltage stability of renewable energy bases remains unclear. To address this issue, a static voltage stability analysis method for multi-infeed systems with renewable energy and multiple SVGs is proposed. Firstly, the power flow Jacobian matrix and characteristic equation of the multi-infeed system with multiple SVGs are derived, suitable for static voltage stability analysis. Secondly, under certain assumptions, it is proved that the static voltage stability analysis of the original multi-infeed system can be simplified to analyzing the static voltage stability of the weakest characteristic subsystem, and it is demonstrated that the generalized short-circuit ratio (gSCR) is applicable to the static voltage stability analysis of multi-infeed systems with multiple SVGs. On this basis, two sufficient conditions for static voltage stability of the system in the constant reactive power control mode of multiple SVGs are provided. Finally, it is shown that when SVGs adopt the constant AC voltage control mode, the improvement in system static voltage stability is superior to that in the constant reactive power control mode. Simulation results verify the theoretical analysis and the correctness of the proposed static voltage stability analysis method.关键词：renewable energy;multi-infeed system;static var generator (SVG);generalized short-circuit ratio (gSCR);static voltage;stability;system strength12|0|0更新时间：2026-10-22
- 摘要：Accurate evaluation of the wide-band impedance characteristics of grid-connected converters for renewable energy is an important approach to analyzing and resolving wide-band oscillations in renewable energy grid-connected systems. Traditional invasive impedance measurement methods have limitations, such as the low measurement speed of frequency-sweep injection and the requirement for three-phase simultaneous injection, and they also fail to consider the frequency-coupling interference caused by wide-band injection. This paper proposes a sequence impedance measurement method based on two-phase wide-band harmonic disturbance injection for three-phase grid-connected converters. By injecting two sets of wide-band harmonic disturbances with equal amplitude and 180° phase difference into any two phases, positive-sequence and negative-sequence disturbances are injected simultaneously in one step, thereby reducing one injection step and significantly improving the measurement speed. To address response aliasing induced by the positive-sequence and negative-sequence frequency coupling during wide-band injection, this paper proposes an odd/even segment frequency grouped injection strategy that interleaves the effective responses with the coupling responses to prevent frequency aliasing. A series-type wide-band impedance measurement device based on the back-to-back converter is also developed, which enables controllable output and precise injection of wide-band harmonic disturbance signals. Finally, the validity and effectiveness of both the proposed method and the measurement device are confirmed via the MATLAB/Simulink simulation and the RT-LAB hardware-in-the-loop experiment.关键词：renewable energy;grid-connected converter;sequence impedance measurement;frequency coupling;wide-band harmonic disturbance;two-phase injection;impedance measurement device9|0|0更新时间：2026-10-22
- 摘要：Grid-forming inverter-based power resources using power semiconductors have weak overcurrent capability, so current limiting needs to be implemented during line faults. However, existing current-limiting strategies mostly focus on symmetrical faults or simple amplitude limitation, often neglecting the specific requirements of grid codes for outputting positive and negative sequence reactive current during the low voltage ride-through period under asymmetrical faults. Moreover, the overcurrent margin of the inverter is not fully utilized, which weakens its voltage support capability. To address this problem, this paper proposes a positive and negative sequence decoupled virtual impedance current-limiting strategy to enhance the voltage support capability. First, based on the grid code, a virtual impedance calculation model with constraints on positive and negative sequence reactive current is established. On this basis, through real-time assessment of the over-limit risk of each phase current, the positive and negative sequence virtual impedance values are adaptively optimized to maximize the utilization of the inverter overcurrent margin, and a safe feasible region for the reactive current proportional coefficient is constructed. This method enhances the support for positive sequence voltage and the suppression capability for negative sequence voltage unbalance while ensuring the grid-forming inverter-based power resources maintain voltage source characteristics. Simulation and experimental results demonstrate that the proposed strategy has good effectiveness and robustness under various asymmetrical faults and different grid characteristics.关键词：renewable energy;grid-forming control;low voltage ride-through (LVRT);asymmetric fault;voltage support;virtual impedance;current limiting;grid code8|0|0更新时间：2026-10-22
Basic Research
- 摘要：The increasingly prominent issues of widening peak-valley disparity and intensified potential voltage and frequency fluctuations in the new power system have significantly increased the requirements for flexibility resources. The hybrid power generation operation of thermal power units and energy storage, leveraging their excellent flexibility supply capabilities and market competitive advantage, can effectively alleviate the regulation pressure on the power system. Therefore, considering the power system flexibility requirements, a bidding strategy for thermal-storage hybrid power generation in the energy and reserve markets is proposed. Firstly, typical scenarios are generated using vine Copula, Latin hypercube sampling, and k-medoids clustering methods to analyze the flexibility of power system in the dimensions of peak shaving, frequency regulation, and voltage regulation. Secondly, considering the power system flexibility requirements in the reserve market, a multi-timescale clearing mechanism covering both the day-ahead energy-reserve market and the real-time market is developed. Then, a non-cooperative game model is established for the bidding of thermal-storage hybrid power generation in the electricity market, which is linearized using the big-M method and McCormick envelopes and solved based on the Karush-Kuhn-Tucker (KKT) conditions and diagonalization method. Case study results demonstrate that the proposed method can effectively improve the net profit of the coordinated operation of the thermal-storage hybrid power generation, which verifies its effectiveness.关键词：new power system;flexibility;electricity market;reserve market;enery storage;non-cooperative game;Nash equilibrium;bidding strategy7|0|0更新时间：2026-10-22
- 摘要：In new power systems, the large-scale grid integration of new loads such as distributed energy resources (DERs) on the user side and electric vehicles (EVs) has intensified the random disturbance characteristics of loads. It is necessary to consider their impacts on static security regions (SSRs) and develop the methods for identifying critical overlimit factors and updating boundaries. To address random disturbances on the load side, this paper proposes a data-model hybrid-driven method for SSR transfer and correction for load change scenarios. This method uses machine learning algorithms to predict SSR coefficients in various load states, constructs transfer boundaries based on the prediction results, and achieves the online correction of SSR boundaries based on system overlimit parameters and an improved loss function, thereby adapting to dominant boundary-change scenarios. Simulation on the IEEE 39-bus system validates the efficiency and accuracy of the proposed transfer and correction method for SSR.关键词：load;distributed energy resource (DER);random disturbance;static security region (SSR);boundary;machine learning;data-model hybrid-driven6|0|0更新时间：2026-10-22
- 摘要：After a line-break fault occurs on the DC-side line of a high-voltage direct current (HVDC) transmission system based on modular multilevel converters (MMCs), the DC voltage of the faulty pole faces the risk of instability. Rapid identification of the line-break section is required to coordinate the MMC switching control for voltage stability. However, the existing line-break protection for HVDC transmission lines is insufficient. Therefore, this paper proposes a new line-break protection principle based on the slopes of the transient current fitting curve. Firstly, the variation characteristics of electrical quantities after HVDC line-break are theoretically analyzed. Secondly, by fitting and analyzing the variation trend of transient current, a line-break fault criterion based on the slopes of the fitting curve is proposed using the distribution characteristics of extreme points on the fitting curve. Furthermore, internal and external faults can be reliably identified by judging whether the DC component of oscillating current approaches zero. Finally, a true bipolar system is built in PSCAD to simulate and verify the performance of the proposed line-break protection. Simulation results show that the proposed protection principle is simple, can be used to quickly and accurately locate the line-break fault section, and exhibits favorable anti-noise performance.关键词：high-voltage direct current (HVDC);modular multilevel converter (MMC);voltage stability;line-break fault;transient current;fitting curve;extreme point;slope5|0|0更新时间：2026-10-22
- 摘要：The phase-shifted diode rectifier (PSDR) transmission topology can achieve harmonic self-cancellation through its topological structure, thereby reducing or even eliminating the need for filtering devices. Compared with conventional diode rectifier transmission schemes, the PSDR transmission scheme has certain cost advantages and shows potential for the application in the field of deep-sea offshore wind power (DSOWP). However, due to the inherent uncontrollability and unidirectional conduction characteristics of the diode rectifier, PSDR converter stations cannot supply power for offshore wind farm startup. Based on the low-voltage and small-capacity auxiliary converter, this paper proposes a low-cost autonomous startup scheme for the DSOWP transmission system using PSDR. By configuring a tapped transformer at two discrete voltage levels in the onshore converter station and paralleling a low-voltage and small-capacity auxiliary converter on both AC and DC sides of the PSDR in the offshore converter station, the system achieves staged operation with low-voltage startup and high-voltage transmission. The main circuit topology and staged operating process of the system are presented sequentially, the control strategy is elaborated, and the control objectives and implementation methods of the auxiliary converter at different stages are detailed. The selection of auxiliary converter capacity and its reactive power compensation effect are analyzed. Finally, full-time-domain simulation is conducted to verify the effectiveness of the proposed scheme and control strategy.关键词：offshore wind power;diode rectifier;phase-shifted diode rectifier (PSDR);startup strategy;converter7|0|0更新时间：2026-10-22
- 摘要：As a promising research frontier, the all-DC technology is expected to play a crucial role in the large-scale collection and transmission of deep-sea offshore wind power in the future. The development of new large-capacity, lightweight DC transformer topologies is vital for advancing the development of all-DC collection and transmission of renewable energy. This paper proposes a symmetrical hybrid high-voltage DC transformer topology. Based on a flexible commutation mechanism, and combining the low conduction losses of thyristors and diode valve groups with the highly controllable characteristics of the sub-module-bridge-arm voltage and current waveforms, the valve groups can be turned on at an ideal low voltage and turned off reliably at a reverse voltage. The sub-module bridge arms actively control the commutation paths and waveforms of the valve groups, dissolving the decoupling between the DC current and the transformer current. The circuit structure, working principle, and control strategy of the proposed topology are described in detail and verified through a 40 kV/400 kV and 100 MW simulation model and a small-power experimental prototype. Finally, the technical economy of the proposed DC transformer topology is demonstrated through a comparative analysis with the existing symmetrical hybrid high-voltage DC transformer.关键词：all-DC technology;offshore wind power;DC transformer;DC/DC converter;topology;flexible commutation;sub-module arm;technical economy7|0|0更新时间：2026-10-22
- 摘要：The oscillator-resembled phase-locked loop-less unified power and voltage controller (OR-PLL-less UPVC) provides a new solution for grid-connected inverters to adapt to the varying and complex grid conditions. However, the OR-PLL-less UPVC does not have the capability of islanded and grid-connected/off-grid switching operation. To this end, this paper develops an enhanced OR-PLL-less UPVC by introducing a compensation current generation module and a pre-synchronization current generation module, which achieves zero-voltage self-start in the islanded mode and bidirectional seamless switching of grid-connected and off-grid modes. First, the voltage self-formation and regulation principles of the OR-PLL-less UPVC based on the compensation current generation module in the islanded mode are described, and the stability of the system in the islanded mode is further analyzed. Next, the structure and operation principle of the pre-synchronization current generation module are introduced, followed by the analysis of the dynamic performance of bidirectional switching of grid-connected and off-grid modes. Finally, the effectiveness of the proposed method is verified through the simulation and real-time controller hardware-in-the-loop experiments. The results show that the inverter using the enhanced OR-PLL-less UPVC can achieve the zero-voltage self-start in the islanded mode and the scheduled switching from the grid-connected mode to the off-grid mode in 20 ms, and the unscheduled switching from the grid-connected mode to the off-grid mode in 40 ms. After meeting the synchronization conditions, the scheduled switching from the off-grid mode to the grid-connected mode occurs within 5 ms to 10 ms, and no inrush current is generated during all bidirectional switching processes.关键词：renewable energy;grid-connected inverter;phase-locked loop (PLL);unified power and voltage control (UPVC);islanded mode;stability;pre-synchronization;grid-connected/off-grid switching14|1|0更新时间：2026-10-22
- 摘要：In DC microgrids, various distributed generation units (DGUs) and loads are tightly interconnected via power electronic converters and power lines. A local fault can trigger cascading effects, which further complicates the state estimation and the fault diagnosis.This paper proposes a multi-agent based distributed optimal state estimation and fault location method. Each DGU is equipped with an agent capable of running a distributed Kalman filter. By adopting a decoupled filtering strategy, each agent eliminates the adverse influences from interconnected subsystems. Thus, the optimal state estimation of the local system is achieved under the minimum variance criterion. Meanwhile, a distributed residual generator is constructed to detect and locate both single and concurrent faults. Finally, the effectiveness and superiority of the proposed method are verified through a DC microgrid system composed of three generation units.关键词：DC microgrid;distributed generation unit (DGU);power electronic converter;state estimation;agent;fault diagnosis;fault location;Kalman filter10|0|0更新时间：2026-10-22
Application Research
- 摘要：The source-grid-load-storage integrated project effectively promotes the local consumption of clean energy by integrating resources of generation sources, power grid, load, and energy storage. Its grid-connected operation relies on reserve services provided by the public power grid. However, there is a contradiction between the reserve demand based on the total system load and the current allocation mechanism based on the net load of entities, which fails to adequately reflect the actual occupation situation of system reserve resources, leading to cost shifting and market fairness issues. Therefore, the underpayment of reserve cost for source-grid-load-storage integrated projects resulting from the flaws in the current allocation mechanism is firstly analyzed, and an improved reserve cost allocation method for source-grid-load-storage integrated projects is proposed to enhance fairness. Secondly, a mathematical model for an analytical framework is developed to realize the comparison and verification between current mechanisms and the proposed method. Finally, sensitivity analysis is carried out for the influencing factors, including the scale of the source-grid-load-storage integrated projects, the internal renewable energy proportion, and the ratio of wind power to photovoltaic. The case study results reveal the flaws of current mechanisms and verify the effectiveness of the proposed allocation method.关键词：source-grid-load-storage;reserve cost;cost allocation;fairness7|0|0更新时间：2026-10-22
- 摘要：In the context of electricity spot markets, how to release the regulation potential of cascade hydropower and optimize the allocation of power resources through market-based approaches is a critical issue. Existing research has proposed various optimal clearing methods and bidding strategies for the participation of cascade hydropower in spot markets, but less consideration has been given to the influence mechanism of the upstream and downstream correlation characteristics of cascade hydropower on clearing prices in the spot market. When the water level of a downstream power station reaches its lower limit, the upstream power stations may be dispatched at low prices, leading to impaired reasonable revenues in the spot market. To address this issue, an in-market pooling mechanism for the revenue compensation of cascade hydropower in the spot market environment is proposed. First, a clearing model for the cascade hydropower participating in the spot market is constructed, and the principle of low-price dispatch of cascade hydropower is illustrated through a simple case. Then, based on the Karush-Kuhn-Tucker (KKT) conditions of the optimization problem, the price characteristics of the hydropower cascade model are derived. Furthermore, by calculating the amount of electricity to be compensated and the price to be compensated, the revenue that downstream power station should refund to the upstream power station can be determined, thereby achieving pooling of upstream and downstream power stations in the spot market. Simulation analysis using actual operation data of the Southern Regional Electricity Spot Market in China demonstrates that the proposed mechanism can effectively mitigate the low-price dispatch phenomenon caused by cascade hydraulic linkages and facilitate a rational distribution of revenues among cascade hydropower stations.关键词：electricity spot market;cascade hydropower;clearing;bidding strategy;shadow price;revenue compensation;pooling9|0|0更新时间：2026-10-22
Engineering Application
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