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最新刊期
卷 46 ， 期 6 ， 2022
- 摘要：From February 8 to 20, 2021, Texas, U.S. experienced a power outage caused by extremely cold weather, which is also the fourth power outage caused by extremely low temperature weather in the U.S. in 10 years. During the accident, the rotating load shedding was up to 4 days, with a peak of 20 GW. More than 4.5 million Texas residents suffered the power outage. The direct and indirect economic losses caused by the accident amounted to US $80~130 billion. The Federal Energy Regulatory Commission (FERC), the North American Power Reliability Commission (NERC) and the regional power reliability organizations published the investigation report of the accident on November 16, 2021, analyzed the main causes of the power outage, and put forward comprehensive and detailed suggestions to power generation enterprises, dispatching agencies and other parties. Combined with the accident investigation report, this paper summarizes the general situation and development process of the accident, analyzes and combs the causes and core suggestions of the accident, and finally analyzes the enlightenment of the accident to China’s power industry.关键词：Texas;power outage;extreme weather;rotating load shedding3|0|0更新时间：2025-06-16
Special Report
- 摘要：In the background of carbon peak, the penetration of renewable energy will further increase. The growing need for renewable energy accommodation can hardly be met due to the lack of flexibility of the current integrated electricity and heat system (IEHS). In this paper, a flexibility reinforcement method based on the decentralized and coordinated multi-stage robust dispatching is proposed. Compared to traditional dispatching methods, the proposed method can fully utilize the flexible resources such as multi-energy storages, electricity-to-heat converters to cope with fluctuations in wind power output. First, the IEHS with multiple flexible resources is modelled. Based on the assumption of wind power forecasting output for the box uncertainty set, and considering the scenarios where the electricity and thermal systems belong to different operators, a decentralized and coordinated multi-stage robust dispatching model is established. In order to measure the flexibility of the dispatching model, a variety of flexibility indicators based on linear programming sensitivity analysis are proposed. Then, a state transition equation of the energy storage based on predict-correction is proposed to ensure the convexity of the model. Furthermore, a decentralized and coordinated robust dual dynamic programming algorithm is proposed, which can quickly solve the model with less information exchange. Finally, an example is used to verify the effectiveness of the proposed model in improving the flexibility of the IEHS and ensuring wind power accommodation.关键词：robust dynamic programming;integrated electricity and heat system (IEHS);decentralized optimization;dual dynamic programming;flexibility3|1|0更新时间：2025-06-16
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Robust-stochastic Reserve Optimization Considering Uncertainties of Failure Probability and Net Load
摘要：The configuration of the reserve is to deal with the uncertainties of possible equipment failures, loads and renewable energy output in the power system. The provision of the adequate reserve for systems is a necessary condition to ensure the safe and economical operation of power systems. In the traditional reserve decision-making methods, the uncertainty of failure probability is ignored in some degrees. Therefore, a robust-stochastic reserve optimization model is proposed to consider the failure probability of equipment and the uncertainty of net load simultaneously. In this model, the net load uncertainty and equipment failure probability uncertainty caused by wind power and load are uniformly described by intervals. And the dual theory, epigraph reformulation and Karush-Kuhn-Tucker (KKT) conditions are adopted to solve the model. Finally, the effectiveness and validity of the proposed method are verified on the IEEE-RTS 24-bus system.关键词：reserve optimization;renewable energy;failure probability;uncertainty;robust optimization;stochastic optimization3|1|0更新时间：2025-06-16 - 摘要：Regional distributed market with energy interconnection allows the members of the small decentralized market to trade flexibly and freely. Therefore, it is necessary to formulate effective market mechanism and transaction strategy with full consideration of the willingness of market players to optimize regional multi-energy market transaction. Firstly, the framework of regional electric and thermal energy market is established. Secondly, by analyzing transaction willingness of participants, an iterative game mechanism of Nash equilibrium with information center is proposed, in which the participants develop transaction strategies to maximize their utility and submit them to the market, and then clear the market operators to maximize the social welfare. The iterative game coordinates the supply and demand relationship of market electric and thermal energy. In view of the complexity in purchasing and selling energy transaction strategy of regional commercial thermal storage station and commercial electricity storage stations, the bidding strategy of energy storage stations is optimized by introducing the bidding quantity control coefficient. Results of calculation example show that the iterative game mechanism can achieve market equilibrium, improve participants’ income and maximize the social welfare. Participation of commercial energy storage stations in the transaction can increase the utilization rate of distributed renewable energy in the regional energy market and realize the optimized transaction of electric and thermal energy, which has good flexibility and economy.关键词：regional energy market;multi-energy market;commercial energy storage station;iterative optimization;market equilibrium3|0|0更新时间：2025-06-16
- 摘要：The charging and discharging of electric vehicles have important reactive power support capabilities for the distribution network. Therefore, a reactive power optimization method considering electric vehicle charging and discharging is proposed. Firstly, the reactive power regulation principle of the charger is analyzed, and a charger state constraint model is established. The constraints of the battery capacity and the users' target power on the power factor angle are satisfied by modifying the state of the charger. Secondly, the quantitative method of reactive power optimization subsidy for users is proposed, the demand indicators on the network side and user side are established respectively, and the objective function of the comprehensive reactive power optimization of the power distribution and consumption system is proposed based on the interests of both parties. Thirdly, the power factor angle of bidirectional charger is used as the optimization variable, and the power factor angle optimization method of charger is proposed based on the particle swarm optimization algorithm. Thus, the reactive power optimization model considering orderly charging and discharging is established to realize the active and reactive power regulation between distribution network and electric vehicle users. Finally, it is verified through simulation that the proposed method can not only improve the voltage curve and reduce the network loss rate, but also significantly reduce user expenditures, while meeting the temporary travel needs of users.关键词：bidirectional charger;power factor angle;orderly charging and discharging;reactive power optimization3|1|11更新时间：2025-06-16
- 摘要：In the background of energy transition, the integrated energy system has developed rapidly. And the multi-energy flow coupling operation mode has increased the complexity of operation. When random factor disturbance occurs, the safe and stable operation of the integrated energy system (IES) will be threatened. In response to this problem, this paper proposes a weakness identification method of IES considering both operation risk and resilience. Firstly, a probabilistic multi-energy flow calculation model for the power-heat-gas coupling IES based on the cumulant method is introduced. Using probabilistic multi-energy flow calculation, the operation risk assessment indicators and assessment method under normal conditions are proposed. Then, for the failure under extreme disasters, the operation resilience assessment indicators are established from the perspective of robustness. Finally, considering both random change of source and load and uncertainty disturbance of random failures, this paper proposes the comprehensive risk-resilience two-dimensional indices to determine the weakness of the IES. The case study shows that the weakness identification assessment method considering risk and resilience can quantitatively analyze the weakness level of the integrated energy system, which verifies the effectiveness of the proposed method.关键词：integrated energy system;probabilistic energy flow;risk assessment;resilience;weakness3|0|7更新时间：2025-06-16
- 摘要：From the perspective of fluctuation patterns of user data for electricity theft,a detection method of electricity theft behavior based on the retrieval of similarity of typical electricity theft behavior is proposed. Firstly, dynamic time warping is used to measure the similarity of consumption data for users with electricity theft behavior, and the similarity matrix of electricity theft is obtained. Secondly, combining with the similarity matrix of electricity theft, the affinity propagation clustering method is used to classify users with electricity theft behavior, so as to realize the automatic clustering of users with electricity theft behavior, and the cluster center is used as typical sample of users with electricity theft behavior. Finally, the similarity of typical users with electricity theft behavior in the electricity database is used to retrieve the users who have similar electricity consumption behaviors, and the suspected users with electricity theft behavior are identified based on manual experience analysis. The feasibility and applicability of the proposed method are verified by an example analysis of the data provided by a provincial electric power company of State Grid of China.关键词：electricity theft behavior;time series;dynamic time warping;affinity propagation clustering;similarity retrieval3|0|0更新时间：2025-06-16
- 摘要：The summer peak-load is the focus of the power industry, and temperature cumulative effect has an important impact on the summer peak-load forecasting. Therefore, a feature decoupling peak-load forecasting model considering meteorological cumulative effect is proposed. The deep neural network model with three input branches is established to realize the decoupling of input features from the structure, which is called feature decoupling model. The three branches take the time feature, load feature and meteorological feature as the input, respectively. The branches for the load and meteorology apply the hidden layer of the long short-term memory (LSTM) network. The load and meteorological sequences are processed based on the time sequence processing ability of LSTM network to the reflect cumulative effect, and then apply it to the peak-load forecasting. Finally, through case analysis and comparison with conventional methods such as temperature correction method, it is verified that the feature decoupling model is more suitable for peak-load forecasting considering cumulative effect.关键词：peak-load forecasting;cumulative effect;long short-term memory (LSTM) network;feature decoupling model5|1|0更新时间：2025-06-16
- 摘要：In order to improve the accuracy of short-term load forecasting, focusing on the construction of feature combinations, a feature combination based on Holt-Winters exponential smoothing (FCHW) is proposed. And combined with the temporal convolutional network (TCN), the FCHW-TCN load forecasting framework is established. Firstly, the Holt-Winters exponential smoothing is applied to the load sequence forecasting, and the level component and seasonal component related to the load sequence are obtained. By using the above components as input features and combining them with conventional features (historical load, date), the FCHW is constructed. Secondly, the TCN is chosen as the forecasting model, and the FCHW acts as the input of the TCN to build the FCHW-TCN forecasting framework. Finally, two different load data sets and multiple forecasting models are used to verify the FCHW and the FCHW-TCN. The results show that the FCHW contributes to the improvement of the forecasting accuracy for models. Compared with other forecasting models, FCHW-TCN forecasting framework has the highest forecasting accuracy and superior forecasting ability.关键词：load forecasting;Holt-Winters exponential smoothing;feature combination;temporal convolutional network (TCN);sequence modeling3|2|0更新时间：2025-06-16
- 摘要：When a large number of inverters are connected to power grids,the problem of harmonic instability will occur. Accurate dq impedance acquisition of grid-connected inverters is one of the key preconditions to analyze the problem. The knowledge-driven white-box modeling methods are difficult to adapt to the actual situation that the information in the engineering field is confidential, but also the black box or grey box measurement methods will continually inject the harmonic disturbances into the actual power system, while the data-driven based methods are hard to determine the input variables reasonably. Aiming at these deficiencies, a combined data and knowledge-driven impedance acquisition method for grid-connected inverter under multiple operating conditions is proposed. Firstly, the knowledge-driven small-signal models are established to pick the input variables. Secondly, combined with the advantages that data-driven can better fit the nonlinear relationship between input and output variables, the kernel extreme learning machine is optimized by the genetic algorithm to obtain the dq impedance under multiple operating conditions. Finally, with the help of RT-LAB, a semi-physical real-time simulation platform is built to verify the effectiveness and superiority of the proposed method.关键词：data-driven;knowledge-driven;grid-connected inverter;impedance;genetic algorithm;kernel extreme learning machine;harmonic stability3|1|0更新时间：2025-06-16
- 摘要：The integrated solar combined cycle (ISCC) system takes the concentrating solar power (CSP) as the main module, and matches with the combined-cycle gas turbine to realize the system stable operation. However, due to the different response speeds of two types of power generation equipments in the ISCC system, the rapid changes on the system demand side can not be responded in time. At the same time, the fluctuations of the system electricity-heat load demand and the randomness of solar radiation will also affect the stable operation of the system. Therefore, this paper establishes the mathematical model of the ISCC system, and uses the inertia power compensation method to make up for the difference in response speed between the two power generation subsystems. Then, the active disturbance rejection control is carried out against the uncertain factors such as the electricity-heat load demand fluctuation (internal disturbance) and the random changes of solar radiation (external disturbance), so the steady output of electric and thermal power is realized. Finally, based on the satellite weather data of National Renewable Energy Laboratory in USA, multi-scenario simulations such as load fluctuations and solar radiation disturbances are carried out on a 100 MW ISCC system, which verifies the superiority and feasibility of the proposed control method and power compensation strategy.关键词：integrated solar combined cycle (ISCC) system;combined-cycle gas turbine;concentrating solar power;active disturbance rejection control;inertial power compensation;coordinated power control3|1|0更新时间：2025-06-16
Basic Research
- 摘要：In order to solve the problem of automatic topology wiring of power flow diagram under complex topology of power grid, an automatic topology wiring method of power flow diagram based on neural network is proposed. By establishing the correlation between the step direction selection of each step of the line and the quality of the generated line, the input layer and output layer of the neural network are constructed, and the autonomous learning of the line topology is further carried out to obtain the optimal solution of the step direction selection function. Finally, the trained step direction selection function is used for topology path retrieval, To solve the problem of how to find the optimal topology connection in the process of automatic wiring of power flow diagram. The algorithm is simulated based on a 220 kV power grid, and the results show the effectiveness and feasibility of the proposed method. Compared with the traditional automatic mapping method, the proposed method does not need to manually adapt the coordinate calculation algorithm of topological connection according to different picture characteristics, and the training process does not need to rely on the existing power flow diagram samples, which can significantly improve the flexibility and accuracy of automatic mapping of power flow diagram.关键词：power flow diagram;automatic wiring;automatic mapping;neural network;topology training3|1|2更新时间：2025-06-16
- 摘要：To make up for the shortcomings of the existing homologous voltage sag detection algorithms and improve the accuracy of the algorithms, this paper proposes an accurate detection algorithm of homologous voltage sag data based on the matching of feature key points for trajectories. Firstly, the root mean square (RMS) waveform of the voltage sag data is converted into a grey-scale trajectory image. Then, the gray-scale trajectory image of the voltage sag is analyzed based on the scale-invariant feature transform (SIFT) algorithm, and the feature key points of the RMS trajectory are extracted. Secondly, the gradient direction information of feature key points is used to match the RMS trajectories of voltage sag data to be detected. Finally, the matching rule is used as the criterion for the judgment of homologous voltage sag data. The proposed algorithm can make up for the shortcomings of the existing homologous detection algorithms, reduce the requirements for the detection data set, and have better engineering applicability and practical application value.关键词：voltage sag;scale-invariant feature transform (SIFT) algorithm;root mean square of voltage;homologous detection;grey-scale trajectory;feature key point;gradient direction3|1|0更新时间：2025-06-16
- 摘要：The droop control is widely used in the engineering practice of voltage source converter based multi-terminal high voltage direct current (VSC-MTDC) system by virtue of its advantages of multi-station coordination to undertake the unbalanced power. Its essence is to redistribute the DC power flow by changing the DC voltage for the unbalanced power accommodation, but the deviation of DC voltage will threaten the safety and economy of the system. Based on the theoretical analysis of the infeasibility of the non-error regulation of DC voltage in the droop control mode, this paper proposes a cooperative optimal droop control strategy of VSC-MTDC system with “quasi non-error” regulation ability of DC voltage to handle the DC voltage deviation caused by unbalanced power consumption. An additional DC voltage controller is designed to automatically adjust the active power reference value, which improves the DC voltage in the dynamic process. In order to obtain the minimum active power variation of the voltage source converter and the nearest DC voltage to the initial value, the reference value increment of droop control is optimized to implement the DC voltage recovery. Simulation results show that the improved strategy can smoothly perform the global optimal regulation of DC voltage at the cost of minimum power variation of multiple voltage source converters, and complete the “quasi non-error” regulation of DC voltage.关键词：voltage source converter based multi-terminal high voltage direct current (VSC-MTDC);DC voltage;droop control;cooperative optimal control;convex optimization;immune clonal section algorithm3|0|6更新时间：2025-06-16
- 摘要：In the islanded microgrid, the microgrid inverter participates in the compensation of system voltage unbalance, which is one of the important ways to improve the power quality in the microgrid. However, under the condition of serious load unbalance, it may occur that the unbalanced voltages at the inverter port and the point of common coupling (PCC) cannot be compensated simultaneously even if the microgrid inverter has a sufficient capacity. Therefore, on the basis of theoretical analysis of coordinated compensation mechanism for unbalanced voltage both at the microgrid inverter port and PCC, the influencing factors of coordinated compensation for unbalanced voltage are firstly discussed. And then the coordinated compensation boundary conditions are analyzed and deduced in detail. Consequently, a quantitative calculation method of unbalanced voltage compensation boundary is proposed. This method takes the voltage unbalance degrees at the microgrid inverter port and PCC as the constraint conditions to obtain the critical current value of the coordinated compensation of the microgrid inverter. Finally, a simulation platform and an experimental platform are established based on the MATLAB/Simulink and the Starsim hardware-in-the-loop simulation platform, respectively. The simulation and experimental results verify the correctness of the theoretical analysis of coordinated compensation boundary and the effectiveness of the proposed method.关键词：microgrid;inverter;unbalanced load;voltage unbalance;coordinated compensation3|0|3更新时间：2025-06-16
- 摘要：The phase-locked loop (PLL) provides reference information synchronized with the grid for the grid-following control of grid-connected inverters. But in the case of weak grids, the PLL with nonlinear characteristics has a certain impact on the stability of the system. Due to the round-off errors, the grid-connected inverters which are designed based on the linearized PLL model may have the risk of instability. In order to ensure the accuracy of the model and the reliability of the stability analysis, a stability analysis method based on the nonlinear state-space model is proposed. First, the nonlinear state-space model of the LCL-type grid-connected inverter system using the second-order generalized integrator based PLL is built, and then the bounded conditions of the nonlinear link in the PLL are established. Based on the Lyapunov stability criterion, the matrix inequality conditions which satisfy the global asymptotic stability are further obtained. By analyzing point by point, the influence of PLL parameters and grid impedance on the stability region of the system is clarified. Experimental results show that, compared with the traditional small signal model, the proposed nonlinear analysis method is more accurate and reliable in predicting the stability of grid-following inverter systems.关键词：grid-following inverter;phase-locked loop;stability analysis;nonlinear model;bounded condition3|1|0更新时间：2025-06-16
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Protection of Flexible DC Distribution Network Based on Single-end Current Transient and Its Setting
摘要：Flexible DC distribution network can efficiently connect distributed generators and DC loads. However, in the case of bipolar short-circuit fault in DC distribution networks, the current rises rapidly and its peak value is high. How to accurately identify and remove the fault area in a short time through the cooperation between protections has become a key problem to be solved. According to the boundary effect of DC/DC converters on the high-frequency information of transient current in DC distribution networks, this paper uses discrete wavelet transform to extract the high-frequency component of the current, and then constructs a two-stage single-end protection coordinated by protection setting value, so as to quickly and reliably identify the fault area. A radial flexible DC distribution network model with DC circuit breaker is built on PSCAD/EMTDC simulation platform. The simulation results show that the proposed protection method can quickly and accurately identify and remove the fault line.关键词：DC distribution network;fault identification;DC/DC converter;discrete wavelet;setting coordination3|1|0更新时间：2025-06-16 - 摘要：Aiming at the validity and complementarity problems of the clustering feature selection for the electricity consumption load data, a feature optimization strategy based on information criteria is proposed and the clustering method for the residential electricity consumption behavior based on the strategy is studied. First, the Bayesian information criterion (BIC) and correlation coefficient are used as the criteria of the validity and relevance of features to optimize clustering features. Then, the truncation distance of the density peak method is optimized by using the cuckoo algorithm. Meanwhile, the idea of outlier detection is used to realize the automatic selection of cluster centers. Finally, according to the optimized feature set and the improved clustering by fast search and find of density peaks (CFSFDP) algorithm, the cluster analysis on the actual residential electricity consumption data is carried out to verify the clustering effect of the proposed method. Experimental results of different clustering methods show that the proposed improved CFSFDP algorithm has the best clustering effect.关键词：information criterion;correlation coefficient;feature optimization strategy;improved density peak method;cluster analysis3|1|5更新时间：2025-06-16
Application Research
- 摘要：Yunnan Power Grid of China is a typical large-scale DC transmission system with a high proportion of clean energy. In the flood season and dry season, there is the problem of insufficient peak and frequency regulation capacities, and the operation mode of deep coupling of peak and frequency regulation makes the intraday dispatch and control more difficult. In order to maximize the accommodation of clean energy, a regional and provincial grid coordinated optimal real-time dispatch method for Power Dispatch and Control Center of China Southern Power Grid and Power Dispatch and Control Center of Yunnan Power Grid of China is proposed. According to the inflow of basin and the transmission section constraint, the positive and negative echelon power plants in the basin are formed through the day-ahead pre-arrangement. According to the intraday real-time operation deviation of the system, the power plants are called based on the echelon order, so as to realize the deviation allocation of the two-level regional and provincial dispatch and control centers, and effectively solve the problems such as the coordination of the regional and provincial grid, the cascade coordination of the hydropower stations, the ramp of hydropower units, the constraint of vibration zone, and the connection to the frequency regulation ancillary service market. The regional and provincial grid coordinated optimal real-time dispatch system has completed the development and deployment, and has been effectively applied in the real-time operation of two-level regional and provincial dispatch and control centers. It has realized the real-time balance of the power generation deviation of Yunnan Power Grid of China and the decoupling of peak and frequency regulation, which has promoted the clean energy accommodation of China Southern Power Grid.关键词：hydropower;real-time optimal dispatch;decoupling of peak and frequency regulation;clean energy accommodation4|0|2更新时间：2025-06-16
- 摘要：The broadband measurement performance of DC current transformer on earth electrode is of great significance to the control and protection of DC transmission systems. Due to the lack of field broadband characteristic test technology and key equipment, the effective field detection has not been carried out. Combined with the actual operation conditions of earth electrodes, a field test technology of broadband characteristics of DC current transformer on earth electrode is proposed in this paper. A miniaturized high-frequency current source and an integrated broadband test device based on digital physical simulation are developed, which solve the problems of high-accuracy acquisition, extraction and data synchronization of multiple types of standard signals. In order to reduce the requirements of field test for the capacity of high-frequency current source, the equivalent analysis model of primary circuit in field broadband test is established, and two feasible schemes for reducing the loop area are proposed. The DC component, frequency response and DC component superposition harmonic detection of DC current transformer on earth electrode are completed on site, which verify the effectiveness of the method.关键词：earth electrode;primary circuit;DC current transformer;frequency response;broadband characteristic3|1|0更新时间：2025-06-16
Engineering Application
- 摘要：Multi-terminal DC transmission and DC power grid technology are effective schemes to solve the problems of centralized grid connection and long-distance transmission of renewable energy power generation. DC power flow controller (DCPFC) is the core equipment for DC power grid steady-state power flow regulation. It can also provide the current limiting capability for DC short-circuit transient fault current suppression. This paper summarizes the development status of DC power grid and its demand for DCPFC. It also summarizes and compares the working principle, advantages and disadvantages and research status of the existing DCPFC, emphatically analyzes the power flow transfer principle, topology and prototype progress of interline DCPFC, and summarizes the current limiting principle, topology and experimental prototype of fault current limiting DCPFC. Finally, the key problems in the research, development and application of DCPFC are prospected.关键词：DC power grid;power flow controller;fault current limiting;topology5|0|0更新时间：2025-06-16
Review
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