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- 摘要：Against the backdrop of high-penetration grid integration of renewable energy, transient overvoltage during fault recovery has become a critical factor restricting the stable operation of power systems and the low voltage ride-through (LVRT) capability. During fault clearance, the phase-locked loop (PLL) can hardly track the grid phase accurately. The resulting phase-locked error induces overvoltage through a dual-channel mechanism of voltage and current. To tackle the above issue, this paper proposes a dual-channel control strategy integrating voltage feedforward and reference current command compensation on the basis of analyzing the action mechanism of phase-locked error. The proposed strategy suppresses the transient overvoltage caused by phase-locked error by collaboratively modifying the voltage feedforward term and current reference value in the current control loop. Compared with methods that improve PLL structure or adopt phase angle compensation, the proposed strategy is easy to implement and has low dependence on phase measurement accuracy. Finally, simulation results under multiple operating conditions verify the effectiveness of the proposed strategy in suppressing transient overvoltage and improving the system's fault ride-through capability.关键词：renewable energy;grid-connected inverter;transient overvoltage;low-voltage ride-through;phase-locked error;voltage feedforward;reference current command3|0|0更新时间：2026-10-16
- 摘要：The grid-forming modular multilevel converter (MMC), owing to its active support capability for weak grids and flexible control characteristics, has become a key interfacing equipment in the power system with renewable energy. Nevertheless, the bifurcation-induced instability mechanisms arising from the coupled effects of periodically time-varying nonlinear characteristics and limiter mechanisms remain unclear. Existing analysis methods face limitations such as model dimensionality explosion or oversimplification of switching processes. To address these challenges, this paper develops a nonlinear time-varying model of a grid-forming MMC under multiple operating conditions based on a method of continuous approximation for switching characteristics. Then, based on the Poincaré mapping, the small-signal stability problem of periodic orbits is reformulated as the local stability problem of fixed points on a hyperplane. In conjunction with automatic differentiation and numerical continuation methods, the evolution rules of Neimark-Sacker bifurcations and fold bifurcations with participation of limiter are analyzed. A participation factor method is further employed to identify the key links affecting system bifurcation, thereby explaining the bifurcation mechanism. Subsequently, the impacts of grid strength and the parameters of the power-synchronization loop, voltage loop, and current loop on the bifurcation points are discussed in detail. Finally, the correctness of the proposed mathematical model and the validity of the analysis results are verified by the PSCAD/EMTDC electromagnetic transient simulation model.关键词：flexible DC transmission;modular multilevel converter (MMC);grid-forming control;nonlinear modeling;periodic orbit;stability;bifurcation theory3|0|0更新时间：2026-10-16
- 摘要：To address the temporal coupling issue of energy storage devices in the intraday scheduling of integrated energy systems, as well as the challenge that carbon-green certificate linked transaction costs cannot be directly measured, an optimal scheduling method based on hybrid model-data-driven and equivalent reconstruction of carbon emission is proposed. First, considering carbon-green certificate linked transactions, the day-ahead carbon emission cost is equivalently reconstructed using carbon emission intensity as a bridge, so as to realize the intraday quantification of carbon emission cost. Then, a hybrid model-data-driven scheduling method is developed. Model-driven optimization is adopted for simple variables. And for variables with strong temporal coupling such as energy storage, an empirical library of optimal state of charge is trained offline based on historical data. In intraday dispatch, combined with intraday data, the Frobenius norm and structural similarity index are used to evaluate the similarity between current and historical data, and locally weighted kernel regression is applied to dynamically generate the reference trajectory of the state of charge, thereby achieving temporal decoupling. Finally, an adaptive updating mechanism of the carbon price coefficient is put forward to guarantee the engineering practicability of the proposed method. Simulation results demonstrate that the proposed method can effectively quantify carbon-green certificate linked transaction costs on the short intraday time scale and improve the accuracy and flexibility of intraday scheduling.关键词：integrated energy system;intraday scheduling;carbon-green certificate linked transaction;carbon emission intensity;data-driven;binary method;temporal coupling3|0|0更新时间：2026-10-14
- 摘要：Mountain-stream rivers in coastal areas commonly face issues such as low base flow during dry seasons, significant tidal fluctuations, and prominent internal nitrogen enrichment, making it difficult to achieve year-round stable water quality through a single water source ecological replenishment model. The mechanisms and temporal response patterns of dual water source collaborative nitrogen control remain unclear. Taking the Xichong River in Shenzhen as the study site, a MIKE21 two-dimensional hydrodynamic-water quality coupling model was constructed based on monthly hydrological, topographic, tidal, and water quality multi-source in-situ monitoring data from 2022. Model calibration and validation were completed using measured data of water level and total nitrogen across multiple cross-sections by season (Nash efficiency coefficient for water level >0.75, relative error for water quality simulation <12%). Four simulation scenarios were designed: no replenishment, single reservoir replenishment, reservoir-coupled single plant reclaimed water, and reservoir-coupled dual plant reclaimed water. From four dimensions—evolution characteristics of flow field stagnant zones, spatial distribution patterns of total nitrogen, water quality improvement efficiency, and proportion of compliant water bodies—quantitative analysis was conducted on the water environment improvement effects of different replenishment modes, exploring the temporal evolution patterns of continuous replenishment (1–3 months) and seasonal differences in water quality improvement. Results show that dual water source joint replenishment can synergistically enhance hydraulic displacement and low-concentration reclaimed water dilution effects. Under the optimal scenario (reservoir replenishment 0.10 m3/s + dual plant reclaimed water replenishment 0.12 m3/s), the comprehensive improvement rate of total nitrogen in the watershed reached 29.5%, and the proportion of surface water compliant with Class III standards increased from 22% to 80%. Water quality improvement efficacy is significantly positively correlated with replenishment duration, with continuous 3-month steady replenishment being the critical threshold for stable river water quality compliance. Due to low-temperature environments, monitored phenomena of sediment internal nitrogen release, and tidal backflow effects, water quality management efficacy during winter dry seasons is significantly lower than in flood and average flow periods. This study elucidates the temporal nitrogen control mechanism of dual water source replenishment in tidal-influenced mountain-stream rivers, providing technical support for long-term ecological replenishment scheduling and refined water quality management of similar coastal rivers in South China.关键词：MIKE21;ecological water replenishment;coastal mountain stream;total nitrogen (TN);water environment improvement;temporal response7|5|0更新时间：2026-10-13
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Spatial Differentiation of the Water-Saving Industry in Guangzhou Based on a Development Heat Index AI导读
摘要：Focusing on the water-saving industry in a broad sense, this study takes the 11 administrative districts of Guangzhou as units of analysis. Following the full-chain logic of "demand–supply–effectiveness," it constructs a Water-Saving Industry Development Heat Index system covering three dimensions: demand foundation, industrial vitality, and water-saving effectiveness. The demand foundation dimension includes per capita GDP, urbanization rate, and the share of the secondary industry; the industrial vitality dimension covers the number of water-saving enterprises, output value, revenue, and R&D expenditure; and the water-saving effectiveness dimension includes comprehensive water use per capita, water consumption per 10,000 yuan of GDP, industrial added value per unit of water consumption, leakage rate of the urban water supply network, reclaimed water utilization rate, effective utilization coefficient of farmland irrigation water, and the share of area covered by the comprehensive reform of agricultural water pricing. Data are drawn mainly from the Guangzhou Statistical Yearbook (2025), the Guangzhou Water Resources Report (2025), project-based enterprise surveys, and district-level self-assessments for water-saving society construction. Quantitative analysis and differentiated functional zoning are conducted using the entropy method, Spearman rank correlation, and Moran's I. To test the robustness of the index results, Monte Carlo perturbation (with ±20% uniform disturbances applied to the baseline weights) and bootstrap resampling are further employed. The results indicate that in 2024, the spatial imbalance of Guangzhou's water-saving industry was pronounced, showing an overall pattern of "prominent industrial highlands in the southeast, agriculture-related districts in the north providing bottom-line support, and strong demand but weak industry in the old urban cores." The comprehensive heat index (including agricultural water-saving indicators) exhibited significant positive spatial clustering (Moran's I 0.570, - 摘要：Driven by the carbon peaking and carbon neutrality policy, the planning of new power systems faces two core challenges. First, economic costs and low-carbon targets cannot be simultaneously guaranteed during the siting and sizing of renewable energy units. Second, insufficient consideration of demand response mechanisms in integrated electricity-carbon planning leads to unfair allocation of carbon emission responsibilities. To tackle the above issues, a dual-level power system planning method considering electricity-carbon integrated demand response under the carbon tax mechanism is proposed. In the proposed dual-level planning model, an improved carbon flow theoretical model incorporating active power losses and charge-discharge characteristics of energy storage is established at the upper level. The model simultaneously optimizes the siting and sizing of renewable energy units and the carbon emission allocation across the whole system. On the basis of the allocation results obtained from the upper level, a tiered carbon tax model for load aggregators is constructed using the Shapley value method. At the lower level, a demand response mechanism is formulated. Dynamic coupling optimization between system planning and demand-side response is realized through iterative solution of the upper and lower layers. Case studies based on practical power system data from a region in Zhejiang Province, China, and the IEEE 118-bus system demonstrate that the proposed dual-level planning model ensures the fairness of carbon emission responsibility allocation and effectively improves the carbon reduction performance of the power system.关键词：new power system;planning;renewable energy;siting and sizing;carbon emission;tiered carbon tax;demand response6|0|0更新时间：2026-10-13
- 摘要：The controllable line-commute converter (CLCC) is a new type of DC converter equipment proposed to address the commutation failure issues in conventional high voltage direct current (HVDC) transmission systems. Research on its dynamic characteristics has become increasingly important under the development demands of power systems. However, CLCC exhibits complex nonlinear characteristics during operation, which makes its modeling and analysis far more challenging than that of the line commutated converter. Traditional modeling methods struggle to effectively describe the dynamic characteristics of nonlinearity and harmonic coupling within the system, consequently affecting the accurate analysis of system dynamic response and stability. This paper proposes a harmonic state space (HSS) modeling approach based on multiple switching functions for the CLCC under the forced commutation condition. By introducing multi-stage switching functions, the method accurately describes the dynamic characteristics during commutation overlap periods, successfully constructing both a small-signal linearized model and an impedance model for the 12-pulse CLCC. In addition, the impact of switching function configuration on modeling accuracy is investigated. Finally, a system stability assessment method based on impedance analysis is employed to analyze key factors influencing system stability. The simulation results demonstrate that the proposed model accurately captures the harmonic impedance characteristics of the CLCC-HVDC transmission system, while revealing that both the gains of the voltage controller and the phase-locked loop controller affect the system stability.关键词：high voltage direct current (HVDC) transmission;controllable line-commutated converter (CLCC);forced commutation;switching function;harmonic state space (HSS);small-signal model;stability analysis5|0|0更新时间：2026-10-13
- 摘要：The static security region (SSR) is a critical tool for analyzing the static security of power systems with high penetration of renewable energy sources characterized by strong uncertainties. As the long-distance inter-regional transmission scale and the integration proportion of renewable energy continue to grow, the dimension of the node injection power space increases sharply, and the nonlinear characteristics of the SSR boundary becomes more pronounced. Constructing the SSR in high-dimensional space faces challenges of the dimension curse and limited accuracy. To address these issues, this paper proposes a geometry-driven construction method of high-dimensional SSR based on dimension reduction of node injection power space. First, the spherical K-means clustering algorithm is employed to classify the violation patterns into distinct clusters and identify critical violation patterns. The correlation coefficients of sensitivity vectors of the critical violation patterns to different node injection powers are calculated, enabling dimension reduction in the high-dimensional space by aggregating node injection powers with similar sensitivity. Subsequently, an initial polyhedron containing the SSR is constructed based on the hyperplanes corresponding to the key violation patterns. The critical secure operating points, along with their corresponding hyperplanes, are computed. A vertex clipping algorithm is then applied to determine the exact SSR boundary. Finally, verification is carried out based on a modified IEEE 39-bs system integrated with renewable energy and a specific provincial power grid. The results demonstrate that the proposed method can significantly improve the computational efficiency and accuracy of the convex SSR .关键词：static security region (SSR);spherical K-means clustering;hyperplane;vertex clipping algorithm3|0|0更新时间：2026-10-13
- 摘要：The mudflow from dam breaches has a wide impact range and significant destructive power, with flow characteristics distinct from clear water. Precisely elucidating its disaster-causing mechanisms holds practical significance. By constructing a parallel framework using OpenMP and establishing a constitutive model based on the Herschel-Bulkley rheology, the APPLIC (Approximated PLIC) method was employed to reconstruct the free surface. A self-developed three-dimensional mathematical model was utilized for viscoplastic dam breach hydrodynamic analysis, revealing the following findings: the current model's predictions align with physical experimental results; the impact force response of non-Newtonian fluids differs from Newtonian hydrostatic pressure variations, governed by equivalent gravity, and exhibits non-hydrostatic pressure effects. Inspired by seal whisker biologics, adjusting the shape to achieve the same drag coefficient reduced the peak impact force of circular cylinders compared to square cylinders by approximately 50%, while significantly diminishing impulse. The streamlined cylinder mitigated momentum changes, thereby reducing impulse. Multi-source data validated the model's reliability, elucidated non-hydrostatic pressure effects, linked biological inspiration with disaster prevention, and provided references for identifying dam breach disaster chains and mitigation applications.关键词：dam break;Herschel‑Bulkley model;approximated‑PLIC scheme;OpenMP technique;bio‑inspiration6|4|0更新时间：2026-10-12
- 摘要：Currently, although the digital twin technology is regarded as a key enabler for the digital transformation of operation and maintenance of in-service power equipment, it is still restricted by deep-seated structural barriers at the data layer in the engineering application. To tackle the above problem, this paper proposes a digital twin driven composite data augmentation architecture integrating physical mechanisms and generative artificial intelligence. The architecture constructs a physics-prior-guided virtual-real symbiotic data base. It adopts high-fidelity multi-physics field simulation to deduce the evolution law of faults, and introduces graph structures to realize physical topology alignment and consistency checking of multimodal heterogeneous data. On this basis, a spatio-temporal coordinated information enhancement strategy is designed. Generative adversarial networks are adopted to capture the temporal dynamic characteristics of equipment operating states, and spatial reconstruction networks are used to establish nonlinear mappings from sparse measuring points to full-domain physical fields, so as to systematically fill data discontinuities. The empirical research targeting typical leakage scenarios of gas-insulated transmission line tunnels demonstrates that the proposed method can effectively break through the constraints of insufficient sensing conditions of in-service equipment, greatly boost the accuracy and cross-domain generalization ability of downstream intelligent diagnosis models, and build a reliable data base to promote digital twins to shift from theoretical frameworks to practical engineering practice.关键词：intelligent operation and maintenance;data augmentation;power equipment;fault diagnosis;digital twin8|0|0更新时间：2026-10-12
- 摘要：With the abolition of the mandatory energy storage allocation policy for renewable energy stations, centralized shared energy storage has become a vital measure to reduce investment costs and improve accommodation efficiency. Nevertheless, information asymmetry exists between renewable energy stations and shared energy storage, which leads to conflicts in benefit distribution. Traditional game methods struggle to effectively coordinate private information. To this end, an operation mechanism of renewable energy station clusters and shared energy storage under asymmetric information is proposed, and a four-stage dynamic game framework of “declaration-decision-optimization-learning” is constructed. Within this framework, renewable energy stations select strategies based on their own types. By observing the behaviors of the stations, the energy storage operator dynamically infers their true types via Bayesian updating, and adjusts pricing and imposes penalties to realize type identification and incentive compatibility. Simulation results under the binary discrete-type scenario of high and low volatility show that the proposed method can effectively mitigate benefit deviations caused by information asymmetry. The leasing price for high-volatility stations is 7% higher than that for low-volatility stations, reflecting the risk premium. The identification accuracy of the true station types through Bayesian updating remains stably above 95%. Compared with the complete-information game, the operator’s revenue increases by 7%, and the dynamic payback period is shortened by 1.6 years. This study provides new theoretical and methodological support for the optimization of multi-agent collaborative shared energy storage systems.关键词：renewable energy station cluster;shared energy storage;capacity leasing;energy sharing;signal game;Bayesian updating3|0|0更新时间：2026-10-12
- 摘要：In the context of constructing new power systems, various types of renewable power generation are being integrated into multiple grid levels at large scale, fundamentally reshaping the power generation mix. This imposes brand new requirements on demand response as a key instrument of supply-demand interaction. This paper reviews the evolution process of the connotation of demand response, showing that it has shifted from a traditional occasional peak-shaving tool toward a significant routine multi-period balancing mechanism, and from broad invitations targeting overall generation-demand balance toward precise responses that account for grid topology. To adapt to this trend, the concept and mechanism of customer directrix load(CDL)-based demand response have been proposed. This paper systematically reviews research progress on CDL-based demand response, including mechanism design, response methods, and related aspects, and identifies that the topology-aware locational customer directrix load(LCDL) and its associated response mechanism represent the development direction for supporting multi-level renewable energy accommodation. Building on this, both the theoretical research framework and the practical implementation pathway of CDL-based demand response are explored. On the theoretical research side, key issues include LCDL calculation, user behavior analysis, and multi-level coordination mechanisms. On the practical implementation side, starting from real-world challenges, implementation approaches are introduced, including parallel-simulation-driven verification methods, multi-level parallel pilot applications, and the construction of a standard system. Finally, this paper outlines the vital role of CDL-based demand response in reshaping users' energy consumption behavior, enhancing system regulation capability, and supporting precise carbon emission assessment.关键词：demand response;customer directrix load(CDL);locational customer directrix load(LCDL);CDL-based demand response;renewable energy accommodation5|0|0更新时间：2026-10-12
- 摘要：To address the existing challenges in aggregation modeling and scheduling of multi-type flexibility resources—such as non-unified descriptions of feasible regions, low coordination efficiency of centralized scheduling frameworks, and conservative uncertainty handling—this paper proposes a distributed scheduling framework based on an improved Dantzig-Wolfe decomposition-column generation (DWD-CG) algorithm, enabling unified aggregation modeling and efficient collaborative optimization of multi-type flexibility resources. First, the Minkowski-sum method is adopted to construct the aggregated feasible region of electric vehicle (EV) clusters, which is further extended to achieve a unified aggregation representation for multiple types of flexibility resources. Second, to describe fluctuations in the proportion of different categories resulting from the electric vehicles clustering, a data-driven norm-based uncertainty set is constructed; to handle the stochastic fluctuation of distributed photovoltaic (PV) generation, a distributionally robust chance-constrained model with a worst-case lower bound under finite samples is introduced. Furthermore, based on the multi-flexibility-entity interaction framework, a two-layer aggregator-cluster collaborative optimization model is formulated, and a distributed solving strategy based on the DWD-CG algorithm is provided. Case studies demonstrate that the proposed framework ensures robust feasibility while achieving better operating cost performance, and achieves higher computational efficiency and scalability compared with conventional methods.关键词：flexibility resource;electric vehicle;temperature-controlled load;demand response;aggregation;distributed scheduling;chance constraint;norm-based uncertainty set6|0|0更新时间：2026-10-11
- 摘要：The reliable identification of secondary neutral line disconnection of current transformers in line protection remains imperfect. Based on the characteristic that secondary neutral line disconnection significantly affects the zero-sequence current but has little influence on the positive- and negative-sequence currents, a method is proposed in which the original pilot differential protection is enabled through positive- and negative-sequence differential protection elements, thereby preventing maloperation during external asymmetric ground faults and incomplete-phase conditions. According to the characteristics of the composite sequence network, a phase-region identification element for internal single-phase ground faults is proposed to prevent three-phase tripping caused by an internal single-phase fault after secondary neutral line disconnection, which would otherwise initiate three-pole tripping and block reclosing. A method for determining whether the fault current has been cleared is also proposed by identifying the return of both positive- and negative-sequence differential protection elements, which eliminates the defect whereby the original protection cannot retract the trip command even after single-phase tripping, resulting in delayed three-phase tripping and failure of reclosing. Simulation tests and practical case verification show that the proposed method can prevent protection maloperation and provide alarm information for secondary neutral line disconnection anomalies.关键词：current transformer;secondary neutral line disconnection;single-phase fault;differential protection;reclosing3|0|0更新时间：2026-10-11
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Evaluation of Waterlogging Defense Resilience Based on a Rainfall-Waterlogging Area Ratio Model AI导读
摘要：Building a resilient urban flood defense system is an effective measure against waterlogging disasters, but quantitative criteria for distinguishing between resilient and brittle defense are insufficient to evaluate the resilience of current and planned defense systems. Analogous to the stress-strain constitutive model of materials, a rainfall-inundation area ratio model for defense systems was developed, introducing a three-stage integrity criterion, characteristic load threshold, hardening discriminant index B, and yield-to-tensile strength ratio λ. Using small watersheds A (plain tidal river network area) and B (hilly area) in Guangzhou as case studies, a three-coupled model was employed to subject four sets of systems (current and planned) to 18 rainfall levels. The results showed hardening discriminant indices of 0.15, 0.60, 0.80, and 1.26 for the planned systems of watershed A and B, and the current systems of watershed A and B, respectively, corresponding to strong, moderate, weak, and brittle resilience. The planned system of watershed B failed at 170 mm with a yield-to-tensile strength ratio of 0.78. The curve morphology can quantitatively distinguish the resilient-brittle nature of defense systems, while the characteristic load and yield-to-tensile strength ratio provide a quantitative basis for planning, design, and super-standard defense measures.关键词：urban waterlogging;resilience evaluation;rainfall-waterlogging area ratio model;stress-strain analogy;tidal river network7|8|0更新时间：2026-10-10 - 摘要：The uncertainty of load in the iron and steel industry poses challenges to the accuracy of load forecasting. Moreover, existing studies that merely adopt data-driven methods ignore the transfer and coupling laws between material flow and energy flow in the production process. To address this issue, this paper proposes a load forecasting method of the iron and steel industry based on physically-guided graph neural networks. First, physics-informed basis functions are constructed based on the attenuation mechanism of transmission processes to accurately characterize the matching and coupling relationships between sequentially connected working procedures. Second, the network structure of iron and steel enterprises is converted into graph data applicable to the forecasting model. Third, an update strategy for the physically-guided graph neural network is designed. In the edge update of the neural network, the physics-informed basis function is adopted as the weight update function to build a load forecasting model with certain physical interpretability. Finally, a case study is carried out taking a domestic iron and steel enterprise as a case. The results show that the proposed model can effectively handle uncertainty and improve forecasting accuracy by integrating physical mechanisms.关键词：load forecasting;iron and steel enterprise;graph neural network;physical information fusion;deep learning3|0|0更新时间：2026-10-10
- 摘要：Facing the features of strong temporal coupling and high uncertainty in power systems with integration of high proportion of renewable energy, traditional online risk identification methods are conservative and difficult to capture temporal correlation risks, an online identification method of high-risk operation modes for power systems considering temporal features is proposed to identify temporal correlation and system stability risks. In terms of temporal risk identification, based on unit segmented ramp rates, system ramp capability is dynamically constructed, combined with net load uncertainty region, an identification method for temporal high-risk operation modes caused by insufficient ramp is proposed. In terms of stability risk identification, a "offline construction - online inspection" convex hull strategy is proposed, which uses sample subsets and incremental Quickhull algorithm to offline construct the safe region of stable operation modes, through online inspection of linear constraints, high-risk operation modes are quickly identified. Actual power grid case verification shows that the proposed method can effectively identify temporal high-risk operation modes caused by insufficient system ramp, significantly improve the identification accuracy of the fuzzy region of transmission sections, still have generalization robustness under sample skewness conditions, and provide technical support for safe and economic operation of power systems.关键词：high-risk operation;convex-hull technique;temporal feature;online identification;ramping capability6|0|0更新时间：2026-10-10
- 摘要：Analyzing the characteristics of electricity market clearing price is an important task for ensuring the fairness and transparency of electricity spot market operation. The China Southern regional spot market clearing needs to considering the operational characteristics of AC/DC hybrid grids and DC tie-lines, and its clearing prices exhibit complex features. This paper proposes an analysis method for sending-end and receiving-end price characteristics in the spot market for regional AC/DC hybrid power grids. First, an electricity spot market clearing model for the China Southern regional power grid is developed, which incorporates transmission tariffs and transmission losses associated with inter-provincial trading components. Then, utilizing the optimal conditions of the clearing model, the relationship of electric energy price difference between the sending-end and receiving-end provinces and the shadow prices of various constraints is derived for two scenarios such as asynchronous interconnection, and AC/DC hybrid interconnection between sending-end and receiving-end provinces. Furthermore, combined with typical market operation scenarios, the influence mechanisms of transmission tariffs, inter-provincial power transmission plan boundaries, operation characteristics of DC tie-lines, interface congestion, and AC/DC hybrid characteristics on the electric energy price difference between the sending-end and receiving-end provinces are elaborated. Finally, tests are conducted using the China Southern regional electricity market simulation system,which verifies that electric energy price difference between the sending-end and receiving-end provinces can be expressed as a linear combination of transmission tariffs and the shadow prices corresponding to inter-provincial power transmission plan boundaries constraints, tie-line operation characteristic constraints, and interface power flow constraints. Based on the theoretical derivation and simulation analysis results, recommendations are proposed for the construction of the China Southern regional electricity market.关键词：electricity spot market;AC/DC hybrid connection;regionl power grid;clearing price;transmission tariff;sensitivity7|0|0更新时间：2026-10-09
- 摘要：In the context of increasingly frequent extreme rainstorms, extending flood forecast lead time while controlling the risk of missed flood-peak warnings has become a core requirement for flash-flood evacuation and reservoir pre-release in small and medium-sized basins. Although radar-based nowcasting and numerical weather prediction can provide basin-total rainfall in advance, a spatiotemporal scale mismatch persists between the areal rainfall totals supplied by meteorological models and the hourly series required by hydrological models. Conventional fixed hyetographs, which rely on a single discrete typical curve, tend to underestimate flood peaks and cannot represent the continuous risk spectrum from normal to extreme rainstorms. This study therefore proposes a dynamic quantile hyetograph method for flood forecasting. Two basins with sharply contrasting rainfall temporal structures were selected: the Jianshan Basin (1,578 km²; asymmetry coefficient A = 3.32; post-peak trailing) and the Hezikou Basin (1,031 km²; A = 0.43; pre-peak concentrated). They provided 15 and 21 flood events, respectively, yielding 36 events in total at a 1-h time step. Areal mean rainfall was derived by Thiessen polygon weighting; a 24-h rainfall sequence centred on the 6-h storm core was extracted, and each event was normalized into a dimensionless hyetograph. Empirical quantiles from 0.3 to 0.9 of the maximum cumulative rainfall over continuous 1–24 h durations were estimated to construct a duration-nested hyetograph library, and the incremental rainfall of each time step was allocated using a greedy pre-peak/post-peak strategy constrained by the basin-specific asymmetry structure. Runoff was simulated with a coupled saturation-excess and infiltration-excess module and routed by a time-invariant unit hydrograph, with all parameters held fixed so that differences could be attributed solely to the temporal rainfall distribution. A one-sided safety factor Kq, derived from the 90th percentile of the underestimation ratio, together with a 200-run Monte Carlo simulation, was used to quantify the underestimation risk induced by total-rainfall bias and quantile-selection error. The results show that the dynamic hyetographs adapt well to the two contrasting runoff concentration regimes. In the Jianshan Basin, all four static hyetographs gave a pass rate of 66.7%, whereas the dynamic P50 hyetograph raised it to 83.3% and reduced error dispersion by 42%. In the Hezikou Basin, the mismatched static hyetographs (fixed P80 and Huff) gave a pass rate of only 57.1%, with a mean underestimation of 22.3% and a maximum of 37.8%, whereas the dynamic P50 hyetograph reached 85.7% and the optimal q reduced the maximum underestimation to 7.1%. Variance decomposition indicates that total-rainfall error is the dominant uncertainty source (about 65%), while q-selection error accounts for about 35%; the mean probability of peak underestimation exceeding 20% is about 8.5%. The quantile q therefore acts as a risk-control variable that shifts the error distribution rather than as a simple accuracy on/off switch, revealing a clear trade-off between overestimation and missed warnings. By decoupling the regulation of rainfall temporal concentration from the total-rainfall safety margin, the proposed method provides a standardized interface from meteorological rainfall totals to hydrological model inputs and supports a three-tier rolling forecast product system comprising baseline, attention, and safety levels. It offers a low-cost and operationally feasible technical basis for flash-flood warning, reservoir pre-release, and rolling flood forecasting in small and medium-sized basins.关键词：flood forecasting;dynamic quantile hyetograph;meteorological–hydrological integration;independent validation;uncertainty;Jianshan Basin;Hezikou Basin4|5|0更新时间：2026-10-08
- 摘要：Under the dual carbon goals, the rational capacity allocation of wind-photovoltaic-thermal-storage renewable energy base in Gobi Desert and other arid areas is crucial for achieving high-proportion renewable energy accommodation and stable transmission. This paper proposes an optimal capacity allocation method of wind-photovoltaic-thermal-storage renewable energy base, taking into account the dual environmental value benefits of China certified emission reduction (CCER) and green certificates. A model for wind-photovoltaic-thermal-storage renewable energy bases and an optimal model for ultra high voltage DC transmission curves are established to provide a model foundation and boundary conditions for optimal allocation. A CCER benefit model considering dynamic marginal emission factors of electricity is established, and a bi-level optimal allocation model integrating solar power CCER benefits and wind-photovoltaic green certificate benefits is further constructed. The upper level aims to minimize the annualized comprehensive cost over the full life cycle, deciding on the capacity of wind-photovoltaic-thermal-storage, while the lower level optimizes the base operation strategy with the annual net operating cost as the objective. Based on a case study of a renewable energy base in Gobi Desert and other arid areas, Shanshan County, Turpan, Xinjiang,China, the technical and economic superiority of the allocation scheme of wind-photovoltaic-thermal-storage and the effectiveness of the proposed method are verified. A sensitivity analysis is conducted to reveal the impact of CCER-green certificate prices and solar multiple on the optimal capacity allocation results. The results show that compared to a wind-photovoltaic-storage scheme, the introduction of solar power generation reduces the annualized comprehensive cost by 33.20% and the total installed capacity by 57.74%. After considering CCER-green certificate benefits, the annualized comprehensive cost decreases by 392 million yuan, and the CCER price at a specific threshold can lead to a sudden change in the capacity allocation scheme. It is necessary to incorporate CCER-green certificate benefits into the optimal capacity allocation of the base.关键词：Gobi Desert and other arid areas;renewable energy base;wind-photovoltaic-thermal-storage;capacity optimization;China certified emission reduction (CCER);green certificate;solar power generation12|2|0更新时间：2026-09-30
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