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最新刊期
卷 47 ， 期 1 ， 2023
- 摘要：As a new generation of high voltage direct current (HVDC) transmission technology, the voltage sourced converter based high voltage direct current (VSC-HVDC) transmission technology has outstanding advantages such as independent control of active and reactive power, fast and flexible response, and strong scalability. It is widely used in wind power integration, grid interconnection, passive network power supply, and long-distance bulk power transmission. Under the construction of the new power system in China, the technical advantages of VSC-HVDC transmission technology will be further highlighted in response to major demands such as the transmission of renewable energy and the safety and stability of the multi-infeed HVDC. This paper sorts out the development status and trends of VSC-HVDC transmission technology, takes several representative VSC-HVDC projects as examples, systematically expounds the engineering practice experience of VSC-HVDC transmission technology in China, and focuses on the application of VSC-HVDC transmission technology in renewable energy integration, grid interconnection and long-distance bulk power transmission. Finally, the prospect of VSC-HVDC transmission technology in the new power system is analyzed, and the challenges it faces are pointed out so as to provide reference for its development and application.关键词：high voltage direct current (HVDC);voltage sourced inverter based high voltage direct current (VSC-HVDC);new power system;renewable energy4|1|0更新时间：2025-06-16
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- 摘要：With a large number of renewable energy sources based on the converter-interfaced generator (CIG) connecting to the power grid, the rotational inertia of the system is decreasing. By using the virtual inertia control and the primary frequency regulation control, the capability of renewable energy sources to actively support the frequency of the power grid can be improved. According to the characteristics of the frequency control response of CIG, this paper proposes an equivalent inertia estimation method for CIG considering power response delay compensation. First, the node frequency and the active power of the point of common coupling of CIG are measured, and the node frequency data is adopted to judge whether the frequency regulation control is triggered. Then, by integrating the active power increment in a long time scale after the frequency regulation control is triggered, the coefficient of primary frequency regulation and the time delay of active power response are calculated. Finally, the active power increment after using the virtual inertia control is corrected and the equivalent inertia is calculated. A closed-loop real-time simulation system is established by using the real-time digital simulation (RTDS) system and the frequency controller for wind, photovoltaic, and energy storage. The correctness of the proposed method is verified with different disturbances and different frequency regulation control strategies, and the influence of key parameters of the algorithm on the accuracy of response time delay calculation is analyzed. The simulation results show that the proposed method is suitable for estimating the equivalent inertia of CIG and has high precision.关键词：renewable energy resource;inertia estimation;virtual inertia;primary frequency regulation;time delay estimation;frequency stability2|1|0更新时间：2025-06-16
- 摘要：With the proposal of the “carbon emission peak and carbon neutrality” goal and the large-scale grid connection of renewable energy clusters, the problem of power system frequency safety is highlighted again. Therefore, by referring to the deep learning method, a two-stage multi-level early warning model for power system frequency safety based on improved residual network is proposed. Firstly, the multi-level fine division for power system frequency safety is carried out, and the multi-level early warning model for power system frequency safety is proposed and constructed. In the first stage, the proposed model uses the classification evaluator based on the improved residual network to evaluate whether the disturbed frequency will exceed early warning value for the safety, and gives the early warning level. In the second stage, the regression predictor is used to further give the risk degree of early warning samples. Finally, the improved IEEE 10-machine 39-bus system and Illinois 200-bus system are taken as examples to test the model. The results show that the model has high early warning accuracy for the safety, which is not only better than other shallow learning methods and deep learning models, but also can accurately forecast the frequency risk degree, and has good robustness and anti-noise ability.关键词：residual network;new power system;frequency safety;multi-level early warning;renewable energy2|1|0更新时间：2025-06-16
- 摘要：Rolling early warning can identify future insecure operation status of power grids and provide decision-making guiding information, which is an effective technique to resist systemic security risks. Considering the uncertainties on source and load sides, a data-driven graded rolling early warning method of dynamic security for large-scale hybrid AC/DC power grid is proposed. First, a control cost based early warning grading strategy is proposed and the control cost of typical control measures is analyzed. The early warning levels are distinguished according to the type of control measures that are needed to ensure the system security. Then, a coordinated multi-time-scale rolling early warning framework is established. Using the characteristic that the prediction accuracy on source and load sides increases as the time to be predicted approaches, the accuracy of the early warning results is improved and it is matched with the control measures of different action sequences. Finally, an incremental learning based online update method of machine learning model is proposed, which uses dynamically added sample data to improve the accuracy of model evaluation, and trains multiple models through replacement sampling to calculate the credibility of early warning results within a given error tolerance. Simulation results of a real power grid demonstrate that the proposed method can effectively track the dynamic security risk situation, and guide the matched control decisions.关键词：early warning;uncertainties;AC/DC power grid;dynamic security;incremental learning;data-driven;extreme weather2|3|0更新时间：2025-06-16
- 摘要：In new distribution systems, more and more users with large load capacity will establish energy management systems (EMSs) to optimize their load curves. This trend brings new challenges to resilience enhancement as well as quick restoration schemes of post-disaster fault for new distribution systems. Hence, a bi-level optimization model is proposed to post-disaster fault restoration for distribution system, which comprehensively considers the profit-seeking feature of EMS, the dispatch of repair crews, and the operation of distributed generators. The outer level of the proposed model develops a general quick restoration model of fault for distribution network, and the spatial behaviors of repair crews are modeled by the temporal-space network (TSN). The inner level of the proposed model describes the process of re-shaping the load curve executed by the EMS according to the conditions of the managed park after the power restoration. To solve such a bi-level optimization problem, Karush-Kuhn-Tucher (KKT) condition is utilized to formulate the original problem into a single-level mixed-integer linear programming problem. Finally, the proposed model is verified on a modified IEEE 33-bus distribution system, and the analysis of sensitivity and computational efficiency is executed.关键词：distribution system;resilience;post-disaster fault restoration;energy management system (EMS);repair crew dispatching;temporal-space network (TSN);bi-level optimization3|0|0更新时间：2025-06-16
- 摘要：The operation mode of active distribution network is frequently switched and its measurement is affected by noise, so its topology identification is required to be real-time and robust. However, the topology identification under limited observation driven by traditional methods is a non-deterministic polynomial (NP)-hard problem. This paper proposes a robust identification method for distribution network topology based on generative adversarial network and partial current phasors. In order to solve the problem of poor generalization ability of traditional supervised learning in unknown topology identification tasks, the conditional generative adversarial network with gradient penalty optimization is used to learn the topology distribution mapped by line current amplitude, phase angle and node load pseudo-measurement. Meanwhile, by constructing generator with one-dimensional convolutional neural network, the sequential current data in continuous observation window are effectively used, which enhances the anti-noise and anti-data loss performance of the algorithm. In addition, the need for only partial current information greatly reduces the investment in observability retrofit of distribution network. Finally, the effectiveness of the proposed method is verified by arithmetic examples.关键词：active distribution network;conditional generative adversarial network;topology identification;partial current;sequential panel data2|1|0更新时间：2025-06-16
- 摘要：The construction of energy storage power stations can alleviate the problem of “abandoned wind and power curtailment” in “Three North” regions in China, and improve the ability of local power grids to accommodate the abandoned wind. However, the high cost of energy storage invested by a single investor limits the popularization and application of energy storage. Aiming at this problem, a hierarchical optimal configuration model of dual energy storage system based on multi-agent investment is constructed. First, a coordinated operation strategy of dual energy storage considering cycle life is proposed to reduce the life loss caused by frequent charge-discharge switching. Then, in order to maximize the benefits of multiple investors, a two-layer optimization economic model is proposed. The upper layer optimization aims to maximize the annual income of the wind farm and the power grid operator, while the lower layer optimization aims to minimize the sum of the charging and discharging capacity indices of dual energy storage. The improved multi-objective slime mould algorithm and fuzzy membership function are used to solve the model. Finally, taking the real-time operation data of a wind farm in Hami, Xinjiang Uygur Autonomous Region, China as an example, the effectiveness of the proposed method is verified.关键词：energy storage;abandoned wind accommodation;multi-agent investment;hierarchical optimization;green certificate trading;multi-objective slime mould algorithm4|2|0更新时间：2025-06-16
- 摘要：Due to the uncertainty of wind power, wind power forecasting errors are unavoidable. The thermal system has the ability to store and release heat. By adjusting the thermal power to shift the wind power, the impact of wind power forecasting errors can be reduced. However, when the wind power is integrated into the integrated electricity and thermal system, the wind power changes frequently, and the thermal system has large inertia and delay, making it difficult to synchronize with the wind power; in addition, different areas of the thermal system respond differently to power system commands. Therefore, in order to solve the problem of non-synchronization of response time when using the thermal system to compensate wind power forecasting errors, a multi-time-scale dispatching strategy of the integrated electricity and thermal system that considers time-sharing compensation of wind power forecasting errors is proposed. First, the evaluation periods of the probability interval error evaluation and the real-time forecasting error evaluation are analyzed, and then the time characteristics of heating area and pipe network in the thermal system are studied. Finally, in the day-ahead stage, the heating area with a slower response speed is used to compensate the probability interval error with a longer evaluation period, and in the real-time stage, the pipeline network with a faster response speed is used to compensate for the real-time forecasting error with a short evaluation period. A multi-time-scale dispatching model is established. The analysis of calculation examples shows that the proposed strategy achieves the time matching of different dispatching periods, different forecasting error evaluation periods, and different response speeds of thermal system areas, which reduces the impact of wind power forecasting errors, and improves the wind power accommodation capacity of the system.关键词：wind power;forecasting error;multiple time scale;thermal inertia of heating area;heat storage and release of pipe network2|1|0更新时间：2025-06-16
- 摘要：Reliability evaluation is an important foundation for the planning and operation of integrated energy system. Both the load thermal inertia and the energy consumption essence of heat users are difficult to be taken into account by the existing reliability indices and evaluation methods of integrated energy system (IES). To this end, the reliability indices and evaluation method of integrated energy system considering thermal comfort level of customers are proposed. Firstly, based on the load thermal inertia model, the reliability index system of IES is established from the perspective of thermal comfort level of customers, including the load-level reliability index and the system-level reliability index. Secondly, on the basis of considering the output correlation of renewable energy and the load demand response, the load shedding strategy considering thermal comfort level of customers is set up, and the reliability evaluation method and process of integrated energy system based on sequential Monte Carlo simulation method are proposed. Finally, an example is given to verify the effectiveness of the proposed method, and the influences of photovoltaic output correlation, load shedding strategy considering thermal comfort level of customers, demand response and coupled reciprocal operation on the reliability evaluation results are analyzed.关键词：integrated energy system;reliability evaluation;thermal comfort level of customers;sequential Monte Carlo method;load shedding2|1|0更新时间：2025-06-16
- 摘要：The existing recommendation methods for the electricity retail plans based on the evaluation information of customers ignore the diversity of differentiated customer evaluation information and only consider the cases, in which customers are good at evaluating all the attributes of the electricity sales, which will bring great deviation to the recommendation results. To this end, a recommendation method for the electricity retail plans based on the bi-level affinity propagation (BLAP) clustering algorithm and multigranular hesitant fuzzy linguistic evaluation set is proposed. Firstly, the division method for the sample customer set based on the customer portrait label system and BLAP clustering algorithm is proposed to identify the customers with similar electricity consumption characteristics. Secondly, considering the multigranular hesitant fuzzy linguistic evaluation set and incomplete weight information, a fuzzy evaluation method for the selection of electricity retail plan by the sample customer set is put forward. Thirdly, based on the information of the sample customer set, the new evaluation method of new customers and the full-ranking recommendation method for the electricity retail plan are proposed, which can realize the accurate recommendation of electricity retail plans by electricity retail companies. Finally, taking customers in an area of China as a case for study, the results show that the electricity retail plan recommendation method for electricity retail plans based on BLAP clustering and multigranular hesitant fuzzy set can help electricity retail companies improve the recommendation quality. Thus, the satisfaction of customers is improved, and the stickiness of customers is enhanced.关键词：electricity retail plan;electricity retail company;customer portrait;bi-level affinity propagation (BLAP) clustering;multigranular hesitant fuzzy set;satisfaction evaluation2|1|0更新时间：2025-06-16
- 摘要：Aiming at the issue that the existing price-based demand response models are difficult to accurately reflect the randomness and fuzziness of response behaviors of users at the same time, and the modeling of demand response based on symmetric cloud model has the problems such as high fitting error and weak solution stability, an uncertainty modeling method for price-based demand response based on multi-step backward cloud generator and semi-cloud model is proposed. The return rate is defined as the unified evaluation standard for the cognition of the return amount by different users, and the mapping relationship model between the return rate and the response behaviors of users based on the semi-cloud model is established. The multi-step backward cloud generator is used to obtain the digital characteristics of the semi-cloud model, and the forward cloud generator is used to generate the distribution cloud map reflecting the response behaviors of users. The simulation examples show that the semi- cloud model has higher fitting accuracy compared with the symmetric cloud model and the traditional price-based demand response modeling method; the multi-step backward cloud generator has better stability compared with the single-step backward cloud generator.关键词：demand response;return rate;semi-cloud model;multi-step backward cloud generator2|1|0更新时间：2025-06-16
Basic Research
- 摘要：Aiming at the distributed active and reactive power coordinated optimal dispatch of networked microgrids, a distributed multi-agent deep reinforcement learning method is proposed. The method can be used to train the agents to learn the optimal dispatch strategy in the process of interaction with the environment, and overcome the dependence of the traditional optimization method on the model. Compared with the existing multi-agent deep reinforcement learning methods based on the “centralized training” framework, the proposed method does not need to collect global information, can better protect the information privacy of each sub-microgrid, reduce the communication pressure, and shows robustness to the communication failures in both the training and execution stages. In addition, considering the topology change of networked microgrids and the poor generalization ability of the reinforcement learning model, a transfer reinforcement learning method is proposed, which uses the existing agent knowledge to efficiently train a group of agents for each topology. Finally, through an example of an improved IEEE 33-bus system, the effectiveness of the method proposed in solving the problem of distributed active and reactive power coordinated optimal dispatch of networked microgrids is verified.关键词：networked microgrid;active and reactive power coordinated dispatch;multi-agent;deep reinforcement learning;transfer reinforcement learning3|1|0更新时间：2025-06-16
- 摘要：A large area of wind power in the process of low voltage ride-through will bring continuous active power disturbance to the renewable energy power system. Moreover, due to the limitation of loads, the active power recovers slowly after clearing of the faults, so the form of active power disturbance is not the power step change used in the usual research. At present, there are few researches on the quantification of system frequency characteristics under non-step disturbance. If the non-step disturbance is regarded as a step disturbance, it will bring large analysis error. Therefore, an equivalent device method is proposed to transform the system frequency response under non-step disturbance into an equivalent system frequency response under step disturbance. Then, combined with the equivalent device method and the unified structure approximate characterization method for the device frequency regulation dynamics, the system frequency nadir considering low voltage ride-through process of wind power is quantitatively evaluated. Furthermore, the system frequency regulation parameters are optimized for such scenarios and the system frequency nadir is raised. Finally, the simulation results demonstrate the effectiveness of the proposed quantitative evaluation and enhancement method for the frequency nadir.关键词：wind power;frequency regulation;non-step disturbance;equivalent device method;frequency nadir;low voltage ride-through2|2|0更新时间：2025-06-16
- 摘要：In order to clarify the influences of virtual synchronous generators (VSG) on the subsynchronous oscillations of grid-connected wind power systems, the full-order state-space model of the grid-connected wind power system with VSG is developed. After that, the damping characteristics of the VSG in the subsynchronous oscillation mode is quantitatively evaluated by adopting the oscillation frequency and damping ratio as the quantitative indicators, and the participation factor is calculated to obtain the sensitivity of the control parameters involved in VSG to subsynchronous oscillations. Finally, the validity of the modeling method and the accuracy of the mechanistic analysis are verified by the time-domain simulation. The results show that although the VSG weakens the influences of the inner-loop proportionality coefficient in the rotor-side converter on the subsynchronous oscillations, the coefficient exerts the greatest influence on subsynchronous oscillations, and the integral coefficient of the VSG excitation control imposes a higher influence on the subsynchronous oscillations than the damping ratio.关键词：grid-connected wind power system;doubly-fed induction generator (DFIG);virtual synchronous generator (VSG);subsynchronous oscillation;state space equation4|1|0更新时间：2025-06-16
- 摘要：When the voltage source converter based multi-terminal high voltage direct current (VSC-MTDC) system adopts the linear droop control strategy of active power and DC voltage, the accuracy of the power-sharing among converter stations will be affected by the DC network characteristics. In the scenario that the DC network topology is unknown, a generalized mathematical model between the active power and the DC voltage of the converter station is established. Under the influence of DC network characteristics, the nonlinear feature of active power and DC voltage droop characteristic of the converter station is analyzed. On this basis, a periodical searching based nonlinear droop control strategy for the VSC-MTDC system is proposed, in which the accurate droop characteristic curve of the converter station operating within the possible ranges can be obtained through the searching technique without the prior knowledge of DC network topology and its parameters. Then the accurate active power control of the converter station can be ultimately implemented after the obtained accurate droop characteristic curve is updated to the bottom controller of the converter station. By establishing a four-terminal VSC-MTDC system model with a ring network in MATLAB/Simulink, not only the analysis conclusion of the nonlinear feature for the active power and DC voltage droop characteristics of the converter station is verified, but also the accuracy of the proposed control strategy in restoring nonlinear droop characteristics of converter station as well as power control compared with the traditional linear droop control strategy is demonstrated.关键词：flexible direct current transmission;voltage source converter (VSC);multi-terminal coordination control;power control;droop control;periodical searching2|1|0更新时间：2025-06-16
- 摘要：Aiming at the low utilization rate and poor reliability of the traditional series-connected power quality control device, and the ability of the parallel-connected power quality control device to solve the voltage fluctuation problem needs to be further improved, a multi-function grid-connected converter (MF-GCC) with integrated voltage support and reactive power regulation capability is proposed. When the grid voltage fluctuates, the MF-GCC works in the series access mode to realize the voltage regulation function. When the grid voltage is normal, the MF-GCC works in the parallel access mode to achieve the unit power factor operation on the grid side. Compared with the traditional series-connected power quality control device, the MF-GCC only has one more switch and one more coupling capacitor, which can realize the effective integration of the functions of series-connected and parallel-connected power quality control device. In addition, when the system fails, the port voltage of the active part in the MF-GCC is clamped to zero and the fault current is limited. Thus the reliability of the MF-GCC itself and its connection to grid is fully improved. This paper analyzes the topology structure, working principle, control strategy and parameter design of MF-GCC in detail. Simulation and experimental results verify the effectiveness and feasibility of the proposed topology and control strategy.关键词：grid-connected converter;voltage compensation;current compensation;function integration;fault current limiting;topology optimization;reliability2|0|0更新时间：2025-06-16
- 摘要：The fixed-admittance model is widely used because of its high simulation efficiency in electromagnetic transient simulation. The derived parameterized fixed-admittance model can improve the transient performance through parameter configuration, and has a good effect in the single-inverter simulation. However, when the parameterized fixed-admittance model is applied to a multi-inverter system, the feasible region of the simulation parameter will change due to the coupling, which will affect the transient performance of the system and even lead to instability. Aiming at the above problem, a parameter adjustment strategy based on the fast genetic algorithm is proposed from the aspects of system stability and transient performance. The parameters of the inverters are optimized by the comprehensive objective of convergence speed, fluctuation and coupling degree, and the structure is optimized for the cross-initialization method. The instability problem of the simulation system is avoided and the transient performance is further improved. Finally, an example is given to verify that the simulation model for the multi-inverter system has the ability of adaptive parameter adjustment with high efficiency, and the simulation accuracy is better than the traditional fixed-admittance model.关键词：electromagnetic transient simulation;fixed-admittance model;multi-inverter system;stability;transient performance;fast genetic algorithm;cross initialization2|2|0更新时间：2025-06-16
- 摘要：The neutral point potential balance is always a hot topic in the research of the neutral point clamped (NPC) three-level inverter. The topology of the NPC inverter is introduced and the working principle and shortcomings of the traditional virtual space vector modulation strategy are analyzed in this paper. On this basis, to improve the balance effect of neutral point potential, an improved variable virtual-space-vector modulation algorithm is proposed. The virtual medium vector is redefined by introducing the variable virtual medium vector balance factor. Then the amount of charge generated by the virtual medium vector in a unit switching cycle is analyzed and the vector order is established accordingly, to improve its dynamic balance speed on the basis of maintaining the steady-state accuracy of the neutral point potential. In addition, in the process of establishing the vector sequence, the output state of the system is analyzed and the phase duty cycle method is adopted for optimization, to reduce the output state switching times of the system in the process of dynamic balance. Finally, the effectiveness of the proposed modulation method is verified by simulation and experiments.关键词：three-level inverter;virtual space vector;equilibrium factor;neutral point balance;phase duty cycle method;optimization of output state2|0|0更新时间：2025-06-16
- 摘要：The control function of the high voltage direct current (HVDC) control system to the converter is realized by synchronous firing control. This paper describes two representative synchronous firing control principles in detail from the two links of synchronizing and firing. One of them has the characteristics that harmonic filtering and unbalance processing are carried out by the prefilter in the synchronizing link, and the firing link is equal-interval firing, which is represented by the SIEMENS synchronous firing control. The other has the feature that the firing link contains auxiliary firing control and firing angle limitation, and the synchronous link has no prefilter, which is represented by the ABB synchronous firing control. Then the performances of two types of synchronous firing control are analyzed and compared under AC faults. The characteristics of two types of synchronous firing control are combined, and an improved synchronous firing control is proposed. Then its small-signal model is established. Finally, the step response simulation comparison and AC fault test are carried out. The simulation and test results verify that the improved system has a stronger ability to suppress subsequent commutation failures, and the improvement direction is corrective.关键词：high voltage direct current (HVDC) transmission;synchronous firing control;AC fault;firing pulse;minimum commutation margin control;commutation failure2|0|0更新时间：2025-06-16
- 摘要：Based on the communication requirements of IEC 61850 smart substation services and the basic principle of time-sensitive networking (TSN), TSN technology is applied to ensure the real-time characteristic of substation communication services. The information flow service curve is established based on the switch forwarding principle of the TSN flow scheduling protocol IEEE 802.1Qbv. Based on the packet transmission characteristics of the substation communication network, the arrival curve of the information source is established, and a calculation method of the end-to-end maximum time delay of the substation packet transmission is proposed by using the network calculus theory. Through the simulation analysis of different levels of substation communication network, the results show that TSN technology meets the communication requirement of substation services, especially in ensuring the real-time transmission of time-sensitive services such as key control commands. The proposed maximum time delay calculation method provides a theoretical calculation basis for time delay analysis of applying TSN to smart substations.关键词：smart substation;substation communication network;time-sensitive networking;IEC 61850;network calculus;service curve;arrival curve2|1|0更新时间：2025-06-16
Application Research
- 摘要：The traditional electricity market studies are mostly based on the classical and simplified economic models, using the assumption of rational man and idealized game models. It usually causes a large deviation from the analysis results with the real situations. In recent years, with the gradual opening of various types of electricity market data and the rapid development of data-driven analysis methods, the data-driven research on electricity markets has gradually become a hotspot, and a series of theoretical improvements and practical applications have been achieved in this field. To this end, this paper attempts to review the studies on the data-driven research on electricity markets. Firstly, the development status of traditional electricity market research is summarized and its limitations are analyzed. Secondly, the actual information disclosure and data openness policies of different electricity markets around the world are introduced and compared. Thirdly, the current situation of electricity market research using data-driven analysis technology is reviewed. Finally, the key challenges of data-driven electricity market research are summarized and the future research directions and application prospects are outlined.关键词：electricity market;data-driven;electricity price forecasting;behavior analysis;mechanism design2|1|8更新时间：2025-06-16
Review
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