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最新刊期
卷 47 ， 期 7 ， 2023
- 摘要：Power system is one of the main sources of carbon emissions, and the greenhouse effect formed by the accumulation of carbon emissions will lead to extreme weather and natural disasters, which in turn will affect the renewable low-carbon resources such as hydropower, photovoltaic, wind power, and carbon reduction efficiency of transmission and distribution networks. Therefore, it is important to reveal the mechanism between the natural disaster chain and the carbon reduction efficiency of new power systems. Based on the analysis of the impact of natural disasters on power system carbon emission, this paper establishes the Bayesian network of “natural disaster-power system-carbon emission change”, and proposes an evaluation model for carbon emission changes of power systems considering the interaction among various disasters. And the feasibility of the proposed method is verified by a case of a “rainstorm-landslide-flood” disaster chain.关键词：new power system;carbon emission;natural disaster;Bayesian network2|1|0更新时间：2025-06-16
- 摘要：As the problems of energy and environment are getting more and more social attentions, carbon emission reduction has become the research element of various system planning problems. The integrated energy system plays an important role in improving the efficiency of emission reduction with its unique characteristic of multi-energy coupling. Taking this as the research background, a bilevel Nash-Stackelberg game expansion planning method considering carbon constraints is proposed. According to the proportional sharing principle, the calculation model of carbon flow rate and nodal carbon intensity for the system line is established, and the planning income model of the three main bodies of the power grid company, natural gas company and energy hub considering the constraints of multi-energy carbon flow is constructed. The bilevel Nash-Stackelberg game planning method of fixed point iteration is adopted to solve the game model with the particle swarm optimization algorithm. The Kriging meta-model is introduced to improve the optimization efficiency. The results of the example verify the rationality and effectiveness of the proposed method. The game planning meets the maximization of the respective interests of the three main bodies in the market, and the introduction of multi-energy carbon flow constraints is conducive to guiding investors to increase the construction of green power equipment.关键词：integrated energy system;carbon constraint;expansion planning;game2|2|0更新时间：2025-06-16
Power Energy Transition for Carbon Emission Peak and Carbon Neutrality
- 摘要：Aiming at the centralized and distributed investment modes of shared energy storage (ES) and the operation modes of power sharing and capacity sharing, the multi-scenario optimization models considering the seasonal differences of renewable energy generation and user load are established, and a pricing mechanism based on the ratio of supply and demand is adopted to economically settle the power transaction in the system. In order to evaluate the impact of the load flexibility on ES planning and total system cost, the modeling and sensitivity analysis for flexible load of user are carried out. Finally, combined with the real historical data, different investment and sharing modes are analyzed and compared from multiple perspectives through case studies. And the impact of peak valley electricity price difference and scale investment effect on ES investment and operation is further analyzed. The results show that the operation mode of centralized ES investment and power sharing are more economical.关键词：shared energy storage;investment planning;power sharing;capacity sharing;flexible load2|1|0更新时间：2025-06-16
- 摘要：Along with the low-carbon transformation of the new power system, the proportion of installed renewable energy surges, and the cross-seasonal power and electricity balance between the load and renewable energy further promotes the demand for long-term flexibility. The long-term energy storage has become an emerging capacity resource to maintain the long-term capacity sufficiency of the system. The long-term energy storage has not been considered in the existing capacity cost payment mechanism for the traditional power generation units, so the economic drive for the development of the long-term energy storage is insufficient. Aiming at the mechanism design of the appropriate capacity payment for the long-term energy storage system, a planning scenario reduction method for the variable period time series is proposed based on the dual-granularity time grid structure containing intra-period and inter-period, and a capacity optimization model for the long-term energy storage is established to measure the capacity payment demand. Combined with a case of a renewable energy enrichment region, the validity of the calculation model of the long-term energy storage capacity and payment level is verified. Based on the sensitivity analysis of critical factors, the declined evolution trend of the capacity payment demand for the long-term energy storage is discussed, which provides a reference for the capacity payment mechanism design to promote the sustainable development of the long-term energy storage.关键词：hydrogen storage;long-term energy storage;adaptive capacity optimization;time series scenario generation;capacity payment3|0|0更新时间：2025-06-16
- 摘要：The separate configuration of energy storage in the data centers may lead to low utilization of energy storage and poor economic benefits. Given the above background, a shared energy storage planning approach for the data center alliance considering demand response is proposed, which can take into account the difference and complementarity of energy storage requirements of each data center in different operation scenarios, and maximize the energy storage efficiency while reducing investment cost. Firstly, an operation mode of shared energy storage for the data center alliance is proposed, including the sharing of energy storage capacity, the allocation of investment cost and the distribution method of profit based on Nash bargaining among different scenarios, to guarantee the interest of the alliance members. Secondly, an energy management model at the level of data center room is established considering the participation of batch processing loads and computer room air conditioners in demand response. Next, combined with configuration constraints of shared energy storage, a shared energy storage planning model for the data center alliance considering demand response is established with the goal of maximizing the collective interests of the alliance. A selection method of scenario set for shared energy storage planning is proposed to enable the planning results to cope with a variety of operation scenarios. Finally, four comparative cases are set to verify the effectiveness of the proposed method.关键词：shared energy storage;capacity allocation;demand response;data center alliance;scenario analysis method2|2|0更新时间：2025-06-16
- 摘要：For the uncertainty of distributed renewable energy in the microgrid, the chance-constrained stochastic programming can be used to describe the system operation risk. In the current research, the analytic transformation or selecting typical scenarios is the common strategy to solve the chance-constrained problems. However, the former relies on particular probability distribution functions and the latter’s preset scenarios may deviate from the actual scenarios, which will lead to the problem that the preset operation risks cannot be met. A distributionally robust optimization method integrating data generation technology is proposed to solve the problem of capacity distribution of photovoltaic and energy storage units in the standalone microgrid, to balance the economy of power supply allocation and the operation risk of the microgrid. First, a photovoltaic output scenario generation method based on an improved generative adversarial network (GAN) is proposed to improve the efficiency of GAN model training and scenario generation. Secondly, the ϕ-divergence is used to measure the deviation between the generated data of GAN and real data, and the distributionally robust chance constraint is used to describe the microgrid operation risk under the corresponding photovoltaic and energy storage capacity. Then, a distributionally robust optimization method based on variation distance, sample average approximation principle and linearization technology is proposed to ensure the efficiency in solving the optimization problem while making full use of the scenarios generated by GAN. Finally, the 33-bus and 123-bus systems are used for the simulation analysis to verify the effectiveness of the proposed method.关键词：microgrid;distributionally robust optimization;generative adversarial network (GAN);distributed photovoltaic;optimal allocation;uncertainty2|1|0更新时间：2025-06-16
- 摘要：With the access of a large number of asymmetric loads and nonlinear loads, the power quality problems of the islanded microgrid are becoming increasingly prominent. It is critical to reasonably distribute the unbalanced and harmonic power. Most of the existing distribution strategies devote to realizing the uniform distribution of harmonic and negative current, which can reduce overload risk. However, the distribution control strategy ignores the difference between different inverters in improving power quality. Therefore, this paper proposes a power distribution strategy aimed at improving the power quality of the microgrid, which takes the core idea of making full use of the residual capacity of inverters. The proposed strategy takes the difference between the residual capacity and the output non-fundamental frequency power as the input, and adaptively adjusts the virtual impedance at the fundamental negative sequence and dominant harmonic frequency to ensure that the inverter is not overloaded under stable conditions. Meanwhile, it can provide the smallest possible flow path of impedance for harmonic current and negative current to achieve the goal of improving the power quality of the microgrid. To ensure the stability and rapidity of the virtual impedance adjustment, the stability region of the virtual impedance is determined based on the root locus distribution, and an improved variable integral control method is also proposed. Finally, the feasibility and the effectiveness of the proposed control strategy are verified by the simulation and the hardware-in-the-loop experiment.关键词：islanded microgrid;power quality;residual capacity;adaptive virtual impedance;power distribution;stability;variable integral control2|1|0更新时间：2025-06-16
- 摘要：Multiple equipment types and complex topology are important characteristics of hybrid AC-DC distribution networks. Traditional methods analyze the resonance characteristics by the equivalent modeling of AC-DC-side subnets, which is not conducive to characterizing the interaction between the subnets on both sides. Therefore, this paper proposes a method to build the interaction model of the hybrid AC-DC distribution network without the need of the equivalent of the subnets, which can be applied to complex power grids with multiple nodes on both sides, and reflect the corresponding relationship between node voltages and injected currents on both AC and DC sides through a block matrix. Based on this model, the mechanism of resonance interaction between subnets on both sides is studied, and the interaction rule of resonance frequency and the resonance amplification risk frequency domain between subnets on both sides and within the subnets are analyzed. Finally, a simulation model of hybrid AC-DC distribution network is built to verify the proposed method and analysis conclusions, and the resonance suppression idea is given from the resonance participation degree of nodes and the sensitivity of component parameters.关键词：hybrid AC-DC distribution network;interaction;resonance;participation factor;sensitivity2|2|0更新时间：2025-06-16
- 摘要：Under the target of “carbon emission peak and carbon neutrality”, the distribution network will carry the large-scale application of low-carbon technologies such as distributed generation, electric vehicles and electric heating, which is faced with severe challenges such as insufficient carrying capacity, load imbalance and power quality. And the flexible interconnection technology of the low-voltage distribution area is considered as an effective way to deal with the above challenges. Therefore, the total supply capability (TSC) of the distribution network considering the flexible interconnection of low-voltage distribution station areas is proposed. Firstly, the typical structure and operation mode of the distribution network considering the flexible interconnection of the station areas are given, and the TSC model of the distribution network considering the flexible distribution of multi-port power flow of flexible interconnected devices and multi-level load transfer is established. Secondly, aiming at the nonlinear non-convex characteristics of the proposed TSC model, a model solution method based on branch and bound algorithm is proposed. Then, the TSC of the actual flexible interconnected distribution network is calculated, and the N-1 security verification is carried out. Finally, the variation law of TSC values with different capacities of low-voltage flexible interconnected devices is observed, and the planning and operation suggestions of the flexible interconnected distribution network in the station area are given, which provide a theoretical basis for the large-scale application of the flexible interconnected technology of the low-voltage station area in the distribution network.关键词：low-voltage distribution network;distribution station area;flexible interconnection;total supply capability2|0|0更新时间：2025-06-16
- 摘要：As offshore wind farms gradually become larger, the wake effect has intensified the impact of wind farm power generation efficiency. Existing wake control methods for wind farms have large computational load and limited optimization effect. In this regard, according to the update and clustering of wind farm networks, a two-step power optimization method is proposed. Based on the improved network definition considering the wake effect of offshore wind farms, the optimization is divided into two stages to deal with the impact of optimization actions on the network and power of wind farms. The spectral clustering method is applied to achieve network clustering. Combined with improved equilibrium optimizer to achieve efficient solution, a two-step optimization strategy is implemented by the combination of cluster update and optimization iterations. The results of case simulation show that, compared with centralized optimization, the proposed method has significant optimization effect and significantly shortens solving time. Compared with direct optimization, larger power gain is obtained at the cost of increasing the limited solving time in complex wake correlation scenarios. Finally, the wind farms of different scales and the number of clusters are explored, and the proposed method has good application prospects for large-scale offshore wind farm.关键词：offshore wind farm;distributed optimization;wake effect;network clustering2|2|0更新时间：2025-06-16
- 摘要：With the increasing penetration rate of wind power, its low voltage ride-through behavior has growing impact on the safe and stable operation of power grids. Based on massive field test data, low voltage ride-through response characteristics of direct-driven wind turbines are analyzed, and the whole low voltage ride-through processes are divided into low voltage ride-through process and recovery process. In the low voltage ride-through process, the impact of wind power penetration rate and its power characteristics on the recovery level of the voltage of the grid-connected point is discussed, and the fact is revealed that the delayed voltage recovery will lead to the loss of more wind power which further aggravates the frequency dip. In the recovery process, the sources of the voltage fluctuation caused by the reactive power control switching and reactive power recovery strategy are discussed, which may cause continuous low voltage ride-through and tripping accident of the wind turbine. To suppress the voltage fluctuation and achieve fast and stable voltage recovery, the optimal control strategy of low voltage ride-through for wind turbines are proposed. Finally, the simulation is conducted on PSCAD/EMTDC platform, and the results verify the impact of the low voltage ride-through behaviors of wind turbines on the voltage of the grid-connected point and the effectiveness of the proposed optimal control strategy of low voltage ride-through.关键词：direct-driven wind turbine;low voltage ride-through;frequency dip;optimal control2|1|0更新时间：2025-06-16
- 摘要：Accurate and fast transient stability assessment is very important for the safe operation of the power system. However, the existing methods do not fully exploit the spatial-temporal characteristics of the power grid transient data, which limits the assessment performance of the models. This paper proposes a transient stability assessment method based on a temporal convolution network (TCN) and graph attention network (GAT). This method only takes the measured bus voltage amplitude and phase-angle data as the input. With the advantage that GAT can process the diagram data and establish the power grid topology connection relationship and the unique causal null convolution operation characteristics of TCN, the spatial and temporal characteristics are automatically extracted to realize the accurate assessment of transient stability. In addition, the improved focus loss function is used as the model training target, which can dynamically adapt to the discriminant boundary of the difficult and easy samples in the training process and adaptively deal with the problem of sample imbalance, thus reducing the phenomenon of misclassification of unstable samples and improving the global accuracy. The simulation results of the IEEE 39-bus system and IEEE 145-bus system show that the proposed method is superior in response time, has strong generalization and robustness in the case of topological structure changes and data noise, and meets the accuracy and rapidity requirements of online transient stability assessment.关键词：transient stability;assessment method;deep learning;graph attention;temporal convolution;focus loss;spatial-temporal characteristics2|2|0更新时间：2025-06-16
- 摘要：In the Energy Internet, electric vehicles (EVs) are not only the distributed mobile energy nodes that can participate in the energy demand response (DR), but also the computing nodes that can perform computation tasks and offload some tasks to the mobile edge computing (MEC) center via wireless transmission. Since the computational energy consumption can not be ignored, this paper considers the computation offloading and energy management of massive EVs with computation and energy demands from the perspective of optimizing cost. Considering that the strategies of transmission rate and charging/discharging power of an EV are affected by those of other EVs, the decision-making process of EVs is formulated into a mean field game (MFG). First, the mean field items of the computation price of MEC, transmission interference, and instantaneous electricity price are defined and calculated. Then, the optimal computation offloading and energy management strategy based on MFG are obtained by solving the Hamilton-Jacobi-Bellman-Fokker-Planck-Kolmogorov (HJB-FPK) equations. Simulation analysis results show that the proposed strategy not only can obtain the optimal economic benefits but also are superior in maintaining the stable operation of the power grid.关键词：electric vehicle (EV);energy management;power dispatching;computation offloading;mean field game (MFG);cost optimization2|0|0更新时间：2025-06-16
Basic Research
- 摘要：Demand response aims at shifting peak load to valley load and improving the load profile, so as to enhance the safety and economy of power system operation. Reasonable electricity retail pricing enables to guide users to adjust their energy consumption behaviors, thus facilitating demand response. In this context, an energy consumption behavior learning model and a customized retail pricing strategy are presented. Firstly, characteristics of energy consumption behaviors are analyzed, and long short-term memory networks based on multiple attention mechanisms are exploited to extract feature correlations and construct the energy consumption behavior learning model. Secondly, considering the price risk, a customized retail pricing model is proposed with the goal of fully developing users’ demand response potential. Case simulation results demonstrate the superiority of the proposed learning model compared with traditional deep learning models, and the proposed customized retail pricing strategy is capable of developing time-varying demand response potentials while it is effective to hedge the profit risk for the retailer and the cost risk of electricity purchase for the user.关键词：demand response;electricity retail pricing;energy consumption;Attention mechanism;deep learning2|1|0更新时间：2025-06-16
- 摘要：Aiming at the difficulty of user phase identification due to the concentrated distribution of voltage curves in low-voltage (LV) distribution station areas, this paper proposes a phase identification method based on morphological characteristic clustering of voltage curves in LV distribution station areas. Firstly, the piecewise aggregate approximation (PAA) is used to segment the voltage curves of three phases on the LV side of the distribution transformer and the LV users, so as to extract the main feature information reflecting the overall distribution and reduce the interference of redundant noise. Besides, the introduction of the first-order derivatives and dynamic time warping (DTW) deepens the analysis of the local trend change of each segmented series and integrates it into the distance measurement based on PAA, which not only makes up for the lack of consideration of the trend change information of the voltage curves by the mean value feature, but also reduces the time complexity of DTW. Secondly, this distance measurement is used to determine the similarity of voltage feature series and improve the similarity measurement of traditional k-means clustering, and to construct the phase identification model of LV distribution station areas. Finally, the effectiveness of the proposed method is verified by the analysis of a practical distribution station area.关键词：low-voltage distribution station area;phase identification;piecewise aggregate approximation (PAA);dynamic time warping (DTW);morphological characteristic;K-means clustering2|1|0更新时间：2025-06-16
- 摘要：With a large number of distributed generators connected to the power grid, the distribution network shows an obvious trend of power electronization. As a power conversion interface, the interactive stability of the inverter with the power grid can not be ignored. Reasonable impedance modeling of the three-phase grid-connected inverter is the premise of analyzing the stability and resonance characteristics of grid-connected systems. Harmonic linearization method has been widely concerned as an impedance modeling method with clear physical meaning. Taking the three-phase LCL inverter as the research object, the harmonic linearization model of typical phase-locked loop is established, and the impedance matrix characterizing the frequency coupling effect is obtained. On this basis, a simplified modeling method of harmonic linearization is proposed to model the impedance of three-phase LCL inverter with the typical capacitive current feedback control strategy. Furthermore, considering the interaction between the grid impedance and the inverter impedance matrix, the multi-input multi-output system model is transformed, and a single-input single-output positive and negative sequence impedance model suitable for the stability criterion is obtained. Finally, based on the PSCAD/EMTDC simulation platform, the accuracy of the proposed simplified harmonic linearization modeling method and the corresponding impedance model and the effectiveness for stability analysis are verified.关键词：inverter;phase-locked loop;harmonic linearization;impedance modeling;frequency coupling2|0|0更新时间：2025-06-16
- 摘要：In order to solve the problem of required large energy storage capacity during wind turbine voltage ride-through and ensure the grid-connected stability of wind turbines, an adaptive coordination control method of voltage ride-through for wind turbines based on energy storage is proposed. The proposed control method configures the energy storage at the point of common coupling. According to the power margin of energy storage and rotor adjustment power, an adaptive coordination coefficient is introduced, and the compensation power of energy storage and adjustment power of the rotor inertia are distributed in real time. Thus, the coordination between the wind turbine and energy storage can be implemented. During the fault, the rotor can respond in time and adjust the speed within the allowable range, which is beneficial for the wind turbine to withstand long-term continuous voltage ride-through. Meanwhile, compared with the non-coordinated control and the fixed proportional coefficient coordinated control, the proposed control method can further reduce the required compensation power and capacity of the energy storage during the fault. Finally, the doubly-fed induction generator model and permanent magnetic synchronous generator model are built, and the comparative simulation of continuous voltage ride-through is carried out. Meanwhile, a hardware-in-loop experimental platform is built for the experimental verification. Simulation and experimental results demonstrate the effectiveness of the proposed adaptive coordinated control strategy.关键词：wind power generation;energy storage;voltage ride-through;coordinated control2|1|0更新时间：2025-06-16
- 摘要：To promote the accommodation and utilization of the renewable energy, the lithium-ion battery energy storage system (LiBESS) has been widely used in power systems, resulting in more complicated fault characteristics. An electromagnetic transient modeling method for LiBESS is proposed. Based on the analysis of the fault characteristics, the power converter system (PCS) and the lithium-ion battery taking the external characteristics and the state of charge (SOC) into account are established. The fault ride-through control loop and negative-sequence control loop are introduced into the control strategy of PCS to realize the fault ride-through and eliminate the fluctuation of DC bus voltage. In addition, the difference in fault characteristics of LiBESS under different charging and discharging modes are analyzed through mechanism analysis and simulation verification. Finally, accuracy of the proposed modeling method is verified based on the electromagnetic transient simulation in PSCAD/EMTDC and hardware-in-loop test in RTDS.关键词：lithium-ion battery energy storage system (LiBESS);power converter system (PCS);electromagnetic transient modeling;fault ride-through;negative-sequence control2|3|0更新时间：2025-06-16
- 摘要：The fault detection technology of common single-phase grounding fault in non-solidly grounded system has gradually matured, but the characteristics and detection methods for some special grounding faults still need further study. In this paper, the equivalent circuit model is established for the cross-line different-phase two-point successive grounding fault in the non-grounded system and the resonant grounded system, and the electrical characteristics of the fault path and the non-fault path before and after the grounding fault are analyzed. The analysis shows that the zero-sequence admittance of the non-fault path remains unchanged, but under the condition that the transition resistance of the two grounding points is less than 3 000 Ω, there is a significant difference in at least one of the module values or phase angles of the zero-sequence admittance of the fault path. Based on this, a method for detecting the later fault of the cross-line different-phase two-point successive grounding faults in non-solidly grounded system based on the change of zero-sequence admittance is proposed, which can further realize the later fault line selection and location. Based on digital simulation and actual fault data, the correctness of fault feature analysis and the feasibility of detection method are verified.关键词：non-solidly grounded system;cross-line fault;different-phase two-point successive grounding fault;zero-sequence admittance;fault detection2|0|0更新时间：2025-06-16
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Fast Differential Protection of Low-frequency Transformer Based on Fault Negative Sequence Component
摘要：Low-frequency transformer is one of the core components of low-frequency transmission system. Experiments show that the fault transient process of the low-frequency system is variable, and the short-circuit electrical characteristics of low-frequency transformers are quite different from those of conventional transformers. Due to the slow unblocking speed of the excitation inrush current criterion, the rapidity of the conventional longitudinal differential protection is affected when the low-frequency transformer has an internal fault. This paper presents a fast differential protection for low-frequency transformer based on the principle of fault negative-sequence component direction. Firstly, the transformer internal fault characteristics and the response of the modular multilevel matrix converter (M3C) in the M3C-based low-frequency transmission system are analyzed. Secondly, the influence of the numerical method for negative-sequence calculation on the negative sequence differential is analyzed. and the identification method of the negative sequence component direction of the fault is obtained by analyzing the negative sequence characteristics in the window time of the initial phase of the low-frequency system fault. Furthermore, the discrimination of excitation inrush current under abnormal conditions of transformer is discussed. Finally, a simulation model is established by taking an actual project as a case, and the proposed method is verified by simulation for typical internal faults.关键词：low-frequency power transmission system;differential protection;modular multilevel matrix converter;low-frequency transformer;negative sequence component;excitation inrush current2|0|0更新时间：2025-06-16
Application Research
- 摘要：The DC distribution network has become one of the important development directions for the power system because of its large power supply capacity, high reliability and strong controllability. Power quality is a key issue in the planning, design and operation control of DC distribution networks. This paper discusses the characteristics of the power quality in DC distribution network, and expounds the generation mechanism, impact and evaluation indicators of power quality events. Then, the transfer characteristics of power quality disturbance in DC distribution networks are analyzed. On this basis, the general method and framework of power quality disturbance location are sorted out, and the methods suitable for power quality disturbance location in DC distribution network are discussed. Also, the research status of power quality control in DC distribution network is reviewed, and the control methods of unbalanced voltage, voltage deviation, voltage fluctuation and harmonics are summarized. Finally, the future research trends of the power quality in the DC distribution network are discussed from the aspects of the definition and correlation of power quality indicators, the complexity of multi-level DC distribution network disturbance tracing, and the hybridity of DC power quality dynamic zoning management.关键词：DC distribution network;power quality;generation mechanism;transfer;location2|1|0更新时间：2025-06-16
Review
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