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最新刊期
卷 48 ， 期 5 ， 2024
- 摘要：With the advancement of new power system construction, the security and stability control system presents the trend that the number of control objects increase, the control range enlarges, and the coupling and complexity rise. The existing engineering test verification methods cannot meet the test verification requirements of the future security and stability control systems. Considering that the digital twin technology has the characteristics of high fidelity, real time, and interactivity, and combined with the connotation, model, and architecture of digital twin technology, the architecture of the test verification based on digital twin for the security and stability control system is proposed. Finally, the key technologies involved are prospected.关键词：security and stability control system;test verification;modeling;digital twin3|0|0更新时间：2025-06-16
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- 摘要：To consider the impact of multiple and multi-level uncertainties such as the wholesale tariff and photovoltaic (PV) output of the superior power grid on the interactive game model of electric vehicles (EVs), EV charging stations (EVCSs) and distribution networks, and fully demonstrate the support effect of active management technology for distribution networks, an energy management and trading method of EVs, EVCSs and distribution networks based on distributionally robust optimization (DRO) is proposed. Firstly, an interactive framework of the day-ahead market for distribution network operators (DNOs), EVCSs and EVs is established to address energy management and trading issues of multiple entities within the active distribution network. Secondly, a two-level Wasserstein DRO interactive game model with the goal of maximizing the interests of multiple entities is constructed between DNOs and multiple EVCSs that aggregate EVs considering active network management technology and network constraints. Then, a simplification method combining the Karush-Kuhn-Tucker condition, the duality theory and big-M method is proposed to solve the difficulties caused by multi-level uncertainties problem, and to transform the two-level Wasserstein DRO model into a mixed-integer second-order cone programming model, which is solved with business solver YALMIP/GUROBI. Finally, the effectiveness of the proposed model and method is verified by the numerical simulation.关键词：distributionally robust optimization (DRO);energy management and trading;active distribution network;interactive game;multi-level uncertainties3|2|0更新时间：2025-06-16
- 摘要：The park-level integrated energy system (PIES) has efficient energy utilization rate. However, the problem of high upfront investment in energy storage equipment is still obvious. Therefore, this paper proposes a low-carbon scheduling model of PIES considering shared energy storage features of electric vehicles. Firstly, the operation framework of the PIES is described, and the models of users and microgrid operators with a carbon emission trading mechanism are established. Secondly, the clustering schedulable potential capacity of multiple types of electric vehicles is fully exploited, and an operation strategy utilizing electric vehicles as energy storage units is developed. Thirdly, a Stackelberg game model with multiple users and microgrid operators is constructed to maximize the benefits of each subject in the park. Finally, the PIES of a city is analyzed as a research object. The results show that the established model not only reduces the cost of energy storage equipment in the park, but also effectively reduces carbon emission and achieves a win-win situation between the microgrid operators and the user aggregators.关键词：electric vehicle;schedulable potential capacity;integrated energy system;carbon emission trading;Stackelberg game;demand response3|0|0更新时间：2025-06-16
- 摘要：Promoting demand-side distributed photovoltaic-energy storage integrated development is an important measure to facilitate the penetration of renewable energy in new power systems. However, the high investment cost of energy storage hinders the promotion process of demand-side photovoltaic-energy storage systems. Therefore, there is an urgent need for a reasonable optimal configuration plan of the energy storage capacity to provide users with more rational decision-making basis to improve system economy and environmental friendliness. The majority of existing capacity planning methods simulates the energy storage operation based on typical scenarios, without considering the power fluctuation characteristics between each typical scenario throughout the year and the impact of extreme scenarios on capacity planning results, which makes it difficult to ensure the accuracy of their planning results. To this end, an efficient capacity planning method is proposed for the demand-side energy storage based on scenario linearization reconfiguration. Firstly, based on the typical scenarios in the clustering results, the extreme scenarios throughout the year are approximately linearly represented by the least squares method. Secondly, the results of scenario linearization are embedded into the constraints of energy storage year-round operation, and the scale of the optimization problem is reduced by reconstructing the decision variables. Finally, the economic benefits of demand-side energy storage allocation are analyzed through practical examples, and the proposed planning method is compared with the existing methods on simulation results. The results show that the proposed planning method can reduce the scale of decision variables required by accurate model operation, improve computational efficiency, and achieve more accurate planning results than the existing approximate methods.关键词：new power system;demand side;energy storage;capacity planning;typical scenario;scenario linearization reconfiguration;clustering algorithm3|1|0更新时间：2025-06-16
- 摘要：In recent years, with the gradual decline of distributed photovoltaic subsidies and the growing maturity of energy storage technologies, the distributed photovoltaic energy storage system has gradually become one of the key links in the transformation of energy structure. However, different from the traditional centralized optimization planning framework, the impact of the self-serving behavior of large-scale distributed photovoltaic energy storage users on the operation efficiency of the overall system in the decentralized decision-making mode and the externality value evaluation method still need to be further studied. Therefore, a bi-level model that takes into account the investment decision of distributed photovoltaic energy storage is proposed, which can capture the interaction between the decentralized decision-making behavior of demand-side market members and the operation of the overall system. In this way, the externality value of the distributed photovoltaic energy storage system can be evaluated. Furthermore, an evaluation index system of market operation is designed from two dimensions of individual level and system level. Finally, the effectiveness of the proposed model is verified based on the actual system data.关键词：distributed photovoltaic;distributed energy storage;externality value;decentralized decision-making;bi-level model;net load curve4|2|0更新时间：2025-06-16
- 摘要：In the context of new power system construction, the intermittent and fluctuating output of high proportion of renewable energy brings new challenges to the stable and secure operation of power grids. However, improving the flexible ramping capability of power systems is an important means to cope with the challenges of renewable energy. Therefore, a clearing model for ramping ancillary service markets based on the ramping demand curves with different elasticities is proposed to stimulate the construction of flexible ramping resources through the ramping ancillary service market, and the flexible ramping capability of the power system is enhanced. The calculation model for ramping demand curves with different demand elasticities is established considering that the value of ramping capacity to power systems varies in different intervals. On this basis, three joint clearing models for the ramping and electric energy market considering the different ramping demand elasticities are designed, and the pricing methods for the ramping shadow price and the clearing results of the three models are analyzed. A case is constructed to demonstrate the calculation method and process of the elastic demand curves, and the simulation analysis of the three ramping market clearing models is conducted based on the IEEE 39-bus system. The results show that increasing the ramping demand elasticity can improve the overall operation economy of systems.关键词：high proportion of renewable energy;ramping ancillary service;demand elasticity;clearing model;pricing method3|1|0更新时间：2025-06-16
- 摘要：The rapid growth of renewable energy generation systems makes the frequency safety of power systems face challenges. Aiming at the problems faced in the secondary frequency regulation process of distributed energy storage clusters, a multi-state interval optimization strategy for energy storage clusters considering frequency regulation capability and economic benefits is proposed. This strategy divides all energy storage units into multi-state intervals according to the state of charge (SOC) and then determines the optimized interval combining the automatic generation control (AGC) instructions and the limit power of each interval. For energy storage units in non-optimized intervals, the output power can be directly determined by the output priority. For energy storage units in the optimized intervals, the constraints and synthetic objective function reflecting frequency regulation cost and overall SOC are used to complete the optimal solution to determine the output power. Simulation results demonstrate that the proposed strategy can greatly reduce the calculation of the control center, and the power distribution results can effectively improve the secondary frequency regulation capability of energy storage clusters, while improving the economic benefits of energy storage clusters.关键词：distributed energy storage cluster;automatic generation control;frequency regulation;economic benefit;multi-state interval;power distribution5|0|0更新时间：2025-06-16
- 摘要：With the increase of the wind power penetration rate, accurate and reliable wind power forecasting is an effective measure to improve the accomodation level of wind power. Addressing the issues of insufficient types of wind power data and scarcity of feature quantities in power forecasting, an ultra-short-term forecasting model of wind power based on the dual derivation of hybrid features and error correction is proposed. Firstly, the chaotic noise is applied to the original power features to construct multiple chaotic disturbance features, improving the situation where the distribution of the original power features is too simple. Secondly, a feature derivation algorithm based on immune algorithms is proposed to explore the potential information of wind power data and increase the number of high-quality features. Furthermore, an error forecasting model is constructed to correct the wind power forecasting results and further improve the forecasting accuracy by forecasting the wind power forecasting errors. Finally, based on the actual operation data of Belgian wind farms, a numerical case analysis is conducted. The proposed model shows better forecasting performance and higher accuracy compared with other traditional forecasting models, verifying the effectiveness of the proposed model.关键词：wind power forecasting;wind farm;feature scarcity regression forecasting;feature derivation;error correction;ultra-short-term forecasting5|1|0更新时间：2025-06-16
- 摘要：After a blackout, a reasonable load restoration strategy is of great significance to speed up the power system restoration and reduce the outage losses. To address the low computational efficiency of the load restoration models due to the non-convexity of standard alternating current (AC) power flow equations, an optimization method of the load restoration scheme for power systems with wind power based on the convex hull theory is proposed. Firstly, the convex hull theory and the method for formulating the convex hull of nonlinear functions are briefly introduced. Secondly, to deal with the uncertainty of wind power outputs, the conditional value-at-risk (CVaR) theory is employed to describe the risks brought by the wind power fluctuations. Then, a second-order cone optimization model of the load restoration for the power system based on the convex hull theory in the rectangular coordinate system is proposed, in which the nonlinear term of AC power flow equations is expressed by convex hulls. To solve the problem that parameters of convex hulls cannot be accurately identified, a parameter optimization method based on the iterative update is proposed to reduce the relaxation errors introduced by the convex hull. The proposed model is a mixed-integer second-order cone programming one that can be efficiently solved by commercial solvers. Finally, the effectiveness of the proposed model is verified by employing the IEEE 39-bus system and the modified Guangdong power system of China.关键词：power system;wind power;power flow;load restoration;convex hull theory;rectangular coordinates;mixed-integer second-order cone programming3|0|0更新时间：2025-06-16
- 摘要：The fault of distribution networks with high penetration of electric vehicles (EVs) may have an expanded impact on the operation of distribution networks and transportation networks due to the coupling interaction between the two types of networks. Clarifying the influence of EV charging load on the operation state of distribution networks and transportation networks and the charging load distribution of the charging station is the basis for timely preventing the fault influence. An evolution analysis method for charging characteristics under distribution network faults considering the interactions between power and transportation is proposed. Firstly, considering the influence of the charging load change on the distribution network under distribution network faults, a variable-step-size repeating power flow model considering the sensitivity of the charging load variation is proposed to calculate the total supply capability (TSC) of the distribution network. Secondly, an evolution model of traffic operation state under the fault influences of the distribution network is constructed by combining bounded rational decision-making of users and dynamic traffic equilibrium. Further, taking EV travelling and charging as a coupling unit, the influence of power supply capacity on charging behavior is described based on the improved Davidson function, and the interaction relationship between the two types of networks is established. Finally, the evolution law of charging load and its influence under distribution network faults considering network coupling are simulated and analyzed.关键词：high penetration;electric vehicle;distribution network;transportation network;fault;charging;total supply capability3|0|0更新时间：2025-06-16
- 摘要：This paper studies the influence of transformer magnetic saturation characteristics on overvoltage in the DC transmission system of renewable energy bases, and reveals the mechanism for the overvoltage of renewable energy stations affected by transformer magnetic saturation characteristics. Firstly, the differences in simulation results of overvoltage at the grid connection points of renewable energy stations with or without the modeling of the magnetic saturation characteristics of transformers are introduced. Secondly, the electromagnetic transient simulation model of transformers and the modeling method of the magnetic saturation characteristics are introduced. Then, it is demonstrated that the magnetic saturation characteristics of the transformer during overvoltage would make it absorb reactive power, and the relationship between reactive power absorption and voltage is derived. Subsequently, a method for correcting overvoltage simulation results is proposed for cases that do not consider transformer saturation characteristics. Finally, the correctness and feasibility of the proposed theory and correction methods are verified through small-scale testing cases and a northwest China grid testing case.关键词：renewable energy;transformer;magnetic saturation;overvoltage;electromagnetic transient simulation3|2|0更新时间：2025-06-16
Basic Research
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Online Anomaly Detection of Wind Turbines Based on Hierarchical Spatio-temporal Graph Neural Network
摘要：In the operation of wind farms, accurate and timely fault detection is the key to reducing the operation and maintenance costs of wind turbines. However, the existing detection methods have not fully explored the potential spatio-temporal correlations between functional units, limiting the improvement in detection accuracy. An online anomaly detection method of wind turbines is proposed based on the hierarchical spatio-temporal graph neural network to improve the accuracy of fault detection. Based on the physical structure of wind turbines, functional units are divided into multiple subgraphs to construct a hierarchical spatio-temporal graph neural network, which can fully analyze the correlation strength between various sensor nodes and functional units in wind turbines through graph attention and multi-head attention mechanisms. Additionally, with respect to the temporal correlation of data for the supervisory control and data acquisition (SCADA) system, a dynamic graph neural network and time attention mechanism are designed, which make the normal behavior prediction model capture the temporal correlation, achieving effective integration of spatio and temporal characteristics. Finally, actual data from a wind farm in Shanghai, China confirm that the proposed method is highly effective.关键词：wind turbine;online fault detection;supervisory control and data acquisition (SCADA) system;graph neural network5|0|0更新时间：2025-06-16 - 摘要：The structure of multiple parallel pickup modules is often applied in the high-power inductive power transfer (IPT) system. However, the inconsistent parameters of multiple parallel pickup modules may result in unbalanced current and output power between pickup modules, which reduces the system efficiency and may cause the system failure due to the module overcurrent in severe cases. To solve this problem, this paper proposes a method to balance the current and the output power of multiple parallel pickup modules by connecting the compensation capacitors of all pickup modules in parallel. First, the characteristics of the topologies of the conventional IPT system and the proposed IPT system are analyzed. Then, the influence of the mutual inductance, the self-inductance and the inner resistance of the pickup coil on current distribution and system efficiency is analyzed. Finally, the effectiveness of the proposed method is verified by an experimental platform of the IPT system with four parallel pickup modules. The experimental results show that the current and the output power of multiple parallel pickup modules are almost equal when adopting the proposed method, and the system efficiency is improved by 2.21% compared with the conventional IPT system.关键词：inductive power transfer (IPT) system;multiple parallel pickup modules;compensation capacitor;current balance;output power balance;system efficiency4|0|0更新时间：2025-06-16
- 摘要：First, in order to improve the output waveform quality of modular multilevel converter (MMC) and reduce the operation loss of the device, this paper proposes a hybrid modular multilevel converter (HMMC) topology based on the combined application of Si and SiC devices. Each bridge arm of the topology contains N half-bridge sub-modules based on Si insulate-gate bipolar transistor (IGBT) devices. And a full-bridge sub-module based on SiC metal-oxide-semiconductor field-effect transistor (MOSFET) whose DC-side voltage is half that of the half-bridge sub-module is connected in series on the AC side of each phase. The overall economy is good. Then, a high-frequency and low-frequency hybrid modulation strategy of HMMC for output level doubling is proposed, and the advantage of low switching loss of SiC MOSFET is fully utilized, which reduces the output harmonics of HMMC and reduces the overall operation loss. In addition, the fluctuation rule of the DC-side energy of the HMMC heterogeneous sub-module under the hybrid modulation strategy is analyzed, and a DC-side voltage stability control strategy for high-frequency and low-frequency modules is proposed. Finally, the feasibility of the proposed HMMC topology and modulation strategy is verified by simulation and experiment. The proposed HMMC, the MMC based on a single device and the existing HMMC are comprehensively compared in terms of loss and cost, which proves that the strategy has significant advantages in reducing loss and cost.关键词：modular multilevel converter (MMC);Si IGBT;SiC MOSFET;hybrid modulation;voltage balance control;efficiency optimization4|1|0更新时间：2025-06-16
- 摘要：The analysis of fault characteristics of line breakage fault is the basis of developing line breakage protection scheme. First, taking the metal return line bipolar DC system as the object, according to the state changes of modular multilevel converter(MMC) in the DC system before and after faults,the equivalent circuit model of MMC in the DC system when the fault occurs is obtained based on the superposition theorem,and the equivalent circuit under the line breakage fault of the DC system is constructed. Then,by improving the pole-mode transformation matrix,the composite modulus equivalent network under different fault types is derived to analyze the modulus characteristics of different line breakage faults. On this basis,the phase plane of line breakage fault type identification is constructed by using the change of 2-mode and 0-mode current,and the classification of line breakage faults is realized. Furthermore,the process of line breakage fault identification based on the change of 1-mode current is proposed. Finally,the simulation model is established in PSCAD/EMTDC,and the rapidity and reliability of the proposed protection method are verified关键词：flexible DC;line breakage fault;pole-mode transformation;modular multilevel converter4|0|0更新时间：2025-06-16
- 摘要：In view of the shortcomings that the existing single-ended traveling wave fault location has a blind spot for near-end faults and the error of double-ended traveling wave fault location for near-end fault location is large, which can not meet the needs of engineering, a method for the identification and location of near-end faults based on waveform characteristic recognition is proposed. First, the traveling wave propagation rule of line faults is analyzed, and the waveform is displayed at a fixed resolution. It is found that when the fault is at the near-end, the initial traveling wave and its subsequent waveforms show the characteristics of stacked slow change under the overall macro-observation of the long-time window and the periodic change under the local zoomed-in observation of the short-time window, and the period is related to the fault distance. The near-end fault history samples of different lines can be used as a unified reference to provide tips for fault location. Then, a near-end fault identification method is proposed based on waveform density and sudden change distribution. Finally, the periods of the identified near-end faults are estimated, using the independence of the near-end faults and the knowledge of the mutation period and fault location of the historical samples, the nearest historical samples of the period are searched and the fault location is determined by the known fault distance interpolation. Based on a large number of measured data, the results of simulation tests show that the proposed method can significantly improve the reliability and success rate of single-ended traveling wave location.关键词：fault location;near-end fault;traveling wave;mutation period;nearest neighbor searching;distribution of pixel density4|1|0更新时间：2025-06-16
Application Research
- 摘要：As the construction of new power system accelerates, the energy supply-demand balance paradigm is undergoing a profound transformation from “source-following-load” to “generation-load interaction”. Residential distributed energy resources (RDERs) close to the demand side have the potential to support the clean, low-carbon, safe, and efficient development of the new power system due to their large scale and flexible adjustment capabilities. Based on a comprehensive review of the specific progress of the management of RDERs at home and abroad, this paper elaborates on the role of RDERs in promoting the construction of new power system. First, four types of RDERs, namely household photovoltaics, household energy storage, electric vehicles, and flexible loads, are introduced, and the concept and development of RDER management are elaborated. Then, focusing on the four key characteristics of the new power system, this paper discusses the important roles that RDERs can play in promoting the safe and efficient operation of the power grid, promoting the clean and low-carbon transformation of energy, achieving the flexible adjustment capability, and assisting in the construction of smart integrated systems. Meanwhile, the paper also summarizes the core elements of RDER management from three aspects of policy and management mechanism, hardware facilities and software platforms, management technology and optimization methods, and analyzes the important internal and external influencing factors of RDER management. Finally, future prospects for the RDER management in the new power system are proposed, including four directions of improving policy mechanisms, upgrading infrastructure, optimizing market transactions, and strengthening technological methods.关键词：new power system;residential distributed energy resource;demand response;virtual plant;safe operation;low-carbon transformation;flexible resource;coupled system4|1|0更新时间：2025-06-16
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