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最新刊期
卷 44 ， 期 4 ， 2020
- 摘要：Energy Internet (EI) is an emerging field that integrates cooling, heating, power and gas among physical flow, information flow and value flow. The projects supported by National Natural Science Foundation of China (NSFC）can reflect the trend of research focus on EI in China. In this paper, the NSFC funds in EI in the past decade are comprehensively analyzed from the view of research directions, annual approved quantities, universities and the fund types. The results show that driven by the energy transformation and Internet technology, EI extends the research from smart grid (which centers on electricity) to multiple energy system integration of cooling, heating, power and gas. Predominant universities that in the lead position in “electrical science and engineering” and “engineering thermo-physics and energy utilization” have shown their advantages in the research of EI. The funds of EI reflect the cross integration of the above two disciplines with the electrical engineering, electronics and information systems, computer science, automation, management science and engineering, mathematics, building environment and structure, macro-management and policy of multi-disciplinary.关键词：Energy Internet;multi-energy complement;integrated energy systems;National Natural Science Foundation of China3|2|0更新时间：2025-06-16
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- 摘要：Cyber physical social system (CPSS) is applied to describe the characteristics and interactions of cyber space, physical systems and social agents in complex network systems, and it is designed to provide systematic modeling, inference and decision making. Human behavior modeling is a complex problem in CPSS. Based on the historical and simulated data, this paper employs the generated adversarial network (GAN) for uncertain social behavior modeling. Additionally, the hybrid simulation method is applied to derive the practical problem in the Guangdong electricity spot market of China, namely the potential impact of gas unit subsidies on the market.关键词：hybrid simulation;cyber physical social system (CPSS);generated adversarial network (GAN);electricity market;cost subsidy of gas unit3|0|0更新时间：2025-06-16
- 摘要：Due to the inhomogeneity of power cyber physical system (CPS) network and the dynamics of risk propagation process, it is difficult to determine the critical point of risk outbreak. From the perspective of dependent network, this paper proposes a method for determining the risk propagation threshold of power CPS network based on percolation theory. Firstly, according to topological association and coupling logic, the power CPS network is abstracted as a dual layer complex network with directed unauthorized graph. Asymmetric balls-into-bins distribution method is used to establish “one to many” and “partial coupling” CPS characterization models for non-uniform electric power. Then, considering the directionality between information layer and physical layer links, the percolation probability is introduced to establish the propagation dynamic equation for internal coupling relationship of each layer. Finally, the risk propagation threshold is solved by defining the survival function of the nodes in power CPS network, and the effectiveness of the proposed method is verified by an example of IEEE 30-bus system and 150-bus Barabsi-Albert model.关键词：power cyber physical system;complex network;percolation probability;propagation threshold;propagation dynamics3|1|0更新时间：2025-06-16
Cyber Energy Systems
- 摘要：With the rapid development of distributed renewable energy, the prosumers will become new important stakeholders participating in the grid operation. Considering that the air-conditioning load of the prosumers has good regulation potential, the virtual energy storage (VES) model of air-conditioning load is first established, and the difference between VES and conventional energy storage is analyzed. Considering the characteristics of VES that can participate in intraday regulation and the uncertainty of renewable energy output, a day-ahead robust bidding strategy for prosumers is proposed. Furthermore, an optimal bidding and scheduling strategy combining day-ahead decision-making with real-time adjustment of VES is proposed. The improved column-and-constraint generation (C&CG) algorithm is used to solve the problem. Finally, the specific examples are compared and the results prove the advantages of optimal strategy in the flexible and economic operation of the prosumer. The impact of the uncertainty of renewable energy output, penalty price selection and outdoor temperature on actual results is further analyzed.关键词：prosumer;virtual energy storage;air-conditioning load;robust optimization;column-and-constraint generation algorithm3|2|0更新时间：2025-06-16
- 摘要：A dispatch method with synergy and interaction between integrated energy station and users is put forward to solve the problems that the thermal storage characteristics of building envelopes and subsidy mechanisms of demand response for users are not considered during the operation and dispatch of integrated energy station. Firstly, an elaborate building virtual storage model is established using the indoor air and building envelope as the main parts of heat transfer subject through comprehensive consideration of influences of indoor and outdoor disturbances on thermal process. Secondly, the equipment composition structure of typical energy station with supply of cooling, heating and power systems and a multi-agent interactive transaction relationship among external power companies, integrated energy station and users are established, and a demand response mechanism based on tiered subsidy is proposed. Thirdly, a day-ahead economic dispatch model of energy station is established by taking the maximum operation earnings of energy station as the target, containing external power purchase expenses, incomes through selling power to users, subsidies and start-up/shut-down costs, and the flexible comfort level of users as constraints. The CPLEX solver is adopted to solve the problems. Finally, the practicability and effectiveness of the proposed model and method are verified through examples.关键词：building virtual energy storage;demand response;integrated energy station;optimal dispatch;building envelope3|4|0更新时间：2025-06-16
- 摘要：With the continuous expansion of renewable energy installation capacity and the persistent advancement of integrated energy system research, the gas-fired units deepen the integration of power system and natural gas system as the coupled components and provide a new way for renewable energy accommodation. Since the stochastic scheduling method, interval optimization and robust optimization algorithms have their own shortcomings in dealing with wind power uncertainty, a distributionally robust optimization approach based on fuzzy set of wind power prediction error is proposed to solve the collaborative dispatch problem for power-gas coupled system. Firstly, the principal component analysis is adopted to extract the temporal-spatial scale correlation characteristics of high-dimensional prediction error vector, and a series of moment functions are introduced to describe the distribution information of prediction errors to construct the corresponding fuzzy set. Then, a two-stage distributionally robust optimal ecomomic dispatch model is established. The first stage is used to make the unit commitment decision, power output and reserve configuration by units, and the second stage is used to identify the worst-case distribution of wind power to ensure the effectiveness of the scheduling strategy determined in the first stage. Combining the linear decision rule and dual theory, the above semi-infinite optimization problem can be transformed into a finite-dimensional optimization problem and then solved. Finally, the simulation results verify the validity of the proposed model and solution method.关键词：coupled system;distributionally robust optimization;wind power;collaborative optimization5|1|0更新时间：2025-06-16
- 摘要：The randomness of large-scale electric vehicles (EVs) connected to power grid and wind power output increases the difficulty of safe and economic operation of power system. In view of the unpredictable characteristics of wind power output and considering operational benefits of system and EV aggregators, a robust two-layer stochastic optimal dispatch model of wind power, thermal power and EVs is established. In order to improve the solution efficiency, the interaction between EVs and power grid is constructed based on the approximate Benders algorithm. In addition, in order to solve the problem of difficult coordination and optimization between large-scale EVs, the coupling relationship between individual EVs is decoupled by the auxiliary problem principle, and the joint optimization of EV groups is transformed into the parallel computation of a single EV dispatch, which realizes the individual dispatch of EV. Finally, the simulation analysis of the improved IEEE 39-bus system is carried out to verify the effectiveness of the proposed model and algorithm.关键词：wind power;electric vehicle aggregators;approximate Benders algorithm;auxiliary problem principle;decoupling operation3|0|0更新时间：2025-06-16
- 摘要：With the increasing proportion of nuclear power and intermittent power supply, nuclear power plant (NPP) is facing higher peak-shaving pressure. Since the present mathematical models of NPP participating in peak load regulation are imperfect, a peak-shaving safety output model for NPP is proposed, which effectively unifies the specific safety requirements and flexible regulation patterns of NPP. By means of compacting the constraints and making the peak regulating depth continuous, the shortcomings of the existing models in general applicability, economy and flexibility could be solved. To guarantee accurate safety output under various operation conditions, the feasible region of nuclear power output is shrunk by introducing decoupled auxiliary variables of power up/down and fully considering the coupling characteristics and mutex relationship between power changes. In addition, regulating depth is made to be continuous in order to obtain the optimal regulating depth and time, which increases the flexibility of peak regulating operation mode for NPP. The model could be easy to solve because the non-linear term is equivalently transformed into linear by using the math transformation technique. The simulation results, which verify the validity of the model, show that the proposed model can accurately, flexibly and economically arrange the peak-shaving safety output of NPP and reduce about 5% peak regulating depth and 18% peak regulating cost.关键词：nuclear power;peak load regulation;safety constraint;load following;optimal scheduling3|0|0更新时间：2025-06-16
- 摘要：The integration of large number of distributed generators (DGs) brings risks to the power quality of the network which they are connected to. Thus it is instructive for DGs planning to evaluate the maximum hosting capacity of DGs accessing to a distribution network. An optimization model for evaluating the hosting capacity of the distribution network with DGs access is established. In the model, the objective is to maximize the grid-connected capacity of DGs, and the constraints involve the technical standards of voltage deviation, voltage fluctuation, short-circuit current and relay protection. Based on the sensitivity of a constraint index to DG capacity, a single-constraint segmentation algorithm and a multi-constraint coordination segmentation algorithm are proposed for the model. Based on different initial values of DG capacities, the segmentation algorithms can be carried out in backward and forward methods, respectively. Finally, the maximum hosting capacity of a radial distribution network is computed and analyzed with multiple constraints, multiple sources and multiple DG types, which shows the superiority of the proposed algorithms in the calculation accuracy and efficiency.关键词：distributed generator;maximum hosting capacity;sensitivity segmentation algorithm;multi-constraint coordination method;backward method;forward method;distribution network3|1|0更新时间：2025-06-16
- 摘要：The wind power integration via the modular multilevel converter (MMC) based high voltage DC (HVDC) transmission system is a promising scheme for power transmission, which also faces prominent stability problems. The small-signal impedance analysis method is an effective way to study the stability of interconnected systems. However, it is difficult to accurately build the impedance model of MMC due to its internal dynamic characteristics. By using the multi-harmonic linearization method, this paper develops a small-signal impedance model of the sending-terminal MMC with double closed-loop AC voltage control. Then the influence of current control loop on impedance characteristics is analyzed accurately. For the system in which the wind farms consisting of direct-driven wind generators are connected with MMC-HVDC system, the impedance analysis method is applied to analyze the oscillation of the interconnected system with different bandwidths of current control loop of MMC, which provides a basis for optimal parameter design of current control loop. The simulation results based on MATLAB/Simulink validate the correctness of the impedance model and stability analysis.关键词：modular multilevel converter (MMC);multi-harmonic linearization;current control loop;wind power generation system;stability analysis3|1|0更新时间：2025-06-16
- 摘要：In order to reduce the MMC demand for sub-module capacitance, it is necessary to suppress the capacitor voltage fluctuation of the sub-module. The voltage fluctuation of the sub-module in multilevel modular converter (MMC) will be aggravated with unbalanced power grid voltage. Firstly, the fluctuation of capacitor voltage of MMC sub-module with unbalanced power grid voltage and the influence of third harmonic injection on sub-module voltage fluctuation are analyzed. The amplitude and the phase angle of third harmonic injection with unbalanced power grid voltage are calculated. The modulation voltage peak could be minimized by injecting the designed third harmonic voltage. The fluctuation suppression strategy is designed. Finally, the validity of the proposed strategy is verified by simulating the double-ended hybrid MMC in PSCAD/EMTDC.关键词：modular multilevel converter (MMC);sub-module capacitor;voltage ripple;third harmonic;unbalanced power grid voltage3|1|0更新时间：2025-06-16
- 摘要：Non-intrusive load monitoring (NILM) is an effective way to realize measurement on demand side and optimization of energy efficiency. This paper explores an online NILM method in high-frequency acquisition mode, which ensures the entire process automative and real-time. Firstly, a load-decomposition model is established based on the additivity of load current to obtain the independent load waveform. Moreover, combined with the operation characteristics of load, priori data are obtained without pre-experiment. Then, the load types are judged by Bayesian classification model to construct dynamic feature library of load for every independent user during operation process. Finally, load identification is realized by constructing optimization model to continuously get the state of power consumption of load in real time. The power consumption data measured in actual scenario is used to verify the effectiveness of the method. The method can adaptively construct the dynamic feature library of load for independent users, which improves the weak universality caused by establishing the database in advance. The fast optimization based on feature library ensures the effectiveness and accuracy of identification.关键词：non-intrusive load monitoring (NILM);load separation;load feature library;load identification5|1|0更新时间：2025-06-16
- 摘要：The uncertainties of noise statistics and model parameters will seriously affect the accuracy of dynamic state estimation. To deal with this issue, a new dynamic state estimation approach is developed based on H-infinity cubature Kalman filter (HCKF). Firstly, the dynamic state estimation model of generator is established. Secondly, a constraint criterion for model uncertainties is developed by utilizing H-infinity filtering theory. On this basis, the estimation error covariance matrix in the cubature Kalman filter (CKF) can be updated to suppress the adverse effects on the precision of state estimation caused by parameter uncertainties. Finally, the performance of the proposed method is compared with the CKF method and an improved interpolation extended Kalman filter (IEKF) method in IEEE 10-machine 39-node system and a practical large-area power system. Simulation results demonstrate that HCKF method performs better than CKF and IEKF methods in estimation precision and robustness against model uncertainties, which can restrain the influences of model uncertainties on the dynamic state estimation for generators.关键词：H-infinity filtering;cubature Kalman filter (CKF);state estimation;uncertainty;robustness3|1|0更新时间：2025-06-16
- 摘要：Distributed power flow controller (DPFC) can flexibly improve the transmission capacity of existing lines and thus reduce operation cost of power system, however, the introduction of DPFC increases difficulties and non-convexity of traditional optimal power flow (OPF) problem. A simplified steady-state power model of DPFC is proposed based on its structure and working principle. The feasible region of power flow for line with DPFC in actual power grid is given considering the capacity of series unit of device in operation. On this basis, the semi-definite programming (SDP) method, which is insensitive to the initial value, is extended to establish the optimal model of system with DPFC. And then the primal dual interior point method is used to solve the OPF problem. The test results show that the proposed method can solve the OPF problem with DPFC.关键词：distributed power flow controller;optimal power flow;feasible region of power flow;semi-definite programming method3|0|0更新时间：2025-06-16
- 摘要：Real-time electricity trading in electricity spot market can give full play to market regulation and promote the accommodation of renewable energy. Data empirical research on the impact of renewable energy generation on real-time electricity price has an essential reference value for understanding the operation rules of the spot market and evaluating market maturity. Electricity spot market of Germany is selected to conduct data empirical research. Data of power generation, load, prediction error, price and other factors are collected. The impact analysis of renewable energy generation on real-time electricity price is studied based on feature representation method for time series. Firstly, the time domain models of time series are transformed into feature vectors by using the feature representation method. Secondly, the greedy forward feature selection algorithm is used to extract key features to maximize the differences between factors. Thirdly, the correlation among multiple factors is discussed based on the overall features and key features respectively, and the network of influence mechanism is constructed. The empirical results show that the real-time electricity price in electricity spot market of Germany is mainly affected by prediction error of wind power generation, and the correlation between factors mainly comes from features such as Fourier transformation, wavelet transformation and discrete symbolization. Finally, by the simple comparison between China and Germany, it is pointed out that the real-time electricity price in Guangdong electricity market of China is more affected by the randomness of renewable energy generation than by the prediction error.关键词：renewable energy generation;real-time electricity price;electricity spot market;feature representation3|2|0更新时间：2025-06-16
Basic Research
- 摘要：During the normal operation, the output power of the photovoltaic-battery virtual synchronous machine (PV-battery VSM) tracks its power command, and the PV panel operates at the maximum power point. The deviation between the PV power and the power command is eliminated by the battery power, which suppresses the power fluctuation of the inverter. However, the PV power is fluctuant and uncertain. When the PV power fluctuation exceeds the battery power limit, it will lead to a large DC bus voltage offset and affect the stable operation of the VSM. Control methods for the grid-connected PV-battery VSM considering the battery charging/discharging power limit are proposed to solve the problems above. The inverter, the PV and the battery are controlled coordinately based on the state of charge (SOC) of the battery. The DC bus voltage offset is suppressed and eliminated when the charging/discharging power of the battery reaches the upper limit. The battery is fully utilized for the VSM output power to track the power command, and over-charging/over-discharging of the battery is avoided. The PV-battery VSM system can operate safely and stably. The proposed control methods are verified by simulations based on PSCAD/EMTDC and semi-physical simulations.关键词：virtual synchronous machine (VSM);synchronverter;photovoltaic （PV）;battery;charging/discharging power limit;state of charge (SOC)4|1|0更新时间：2025-06-16
- 摘要：Installing power system stabilizer is an effective means to enhance power system stability with small disturbances. Compared with the traditional single-band power system stabilizer, the multi-band power system stabilizer has more frequency band branches and higher control degrees of freedom, which can better suppress the oscillation mode with lower frequency, but its setting process and method have not been widely studied. A setting method of parameters for multi-band power system stabilizer based on the frequency domain margin index of multi-input-multi-output system is proposed. The method considers several weakly damped oscillation modes in the performance index, adjusts the amplitude-frequency and phase-frequency characteristics of several multi-band power system stabilizers, guarantees the designed stabilizers maximize the system stability margin while providing suitable compensation phase, and ensures the stability of the excitation mode. Case studies of Yunnan power grid of China validate the effectiveness of the proposed method.关键词：power system stabilizer;multi-band power system stabilizer;low frequency oscillation;parameter setting;stability margin of frequency domain3|1|0更新时间：2025-06-16
- 摘要：A method for voltage sag feature extraction and sag source identification based on deep belief network (DBN) is proposed. The feature extraction ability of DBN is used to extract the feature data from the measured waveform data, which solves the problem that the artificial features rely too much on expert experiences and are short of generality. The multi-hidden layer structure network learning feature is used to realize the identification of the sag source. The model integrates feature extractor and classifier together to optimize the model structure and improve the efficiency of sag source identification. The optimal parameters of the model are selected, and DBN model for the measured voltage sag data is established. The feature extraction and sag source identification of the real-time measured sag data of power grid are carried out. The superiority of DBN method in feature extraction and sag source identification is verified, which is available for practical engineering.关键词：voltage sag;deep learning;deep belief network;feature extraction;transient source identification4|0|0更新时间：2025-06-16
- 摘要：A model of the AC/DC converter based on the harmonic state space (HSS) theory is developed, and the AC/DC harmonic coupling characteristics of the converter have been analyzed in depth. Firstly, through the mathematical derivation, the three-phase AC/DC converter is modeled based on the HSS theory. The HSS model includes each harmonic on the AC and DC sides, which reflects the relationship between the harmonic variables of each frequency. Secondly, the harmonic transfer function of the converter is deduced by the model, and the diagram of harmonic coupling impedance is established to analyze the AC/DC harmonic coupling characteristics. The model is built according to the voltage source three-phase AC/DC converter which is commonly used in microgrids. The full range of coupling characteristics between AC and DC side is illustrated, and can be used to explore the harmonic characteristics at all frequencies, and can also be applied in harmonic analysis of converter with parallel and cascaded structures. Finally, the simulation of the voltage source three-phase AC/DC converter is performed in PLECS, and it is compared with the HSS calculation results to verify the proposed model and the study of harmonic coupling characteristics. Furthermore, the proposed model and the conclusion of harmonic coupling characteristics are verified by experiments.关键词：microgrid;converter;harmonic state space (HSS);DC voltage disturbance;harmonic coupling3|1|0更新时间：2025-06-16
- 摘要：Cascaded power electronic transformer (PET) has broad application prospect in medium and low voltage distribution networks. In-depth study of voltage sag isolation capability of cascaded PET is of great value for parameter selection of cascaded PET device, energy storage capacity configuration and reduction of voltage sag treatment devices. Through theoretical deduction, the limiting factors of voltage sag isolation capability of cascaded PET are studied. At the input stage, the effects of modulation ratio, voltage fluctuation of DC link capacitor and RMS limit of switching device current on its voltage sag isolation capability are deeply studied. At the isolation stage, the effects of the phase-shift ratio, RMS and peak limit of switching device on the voltage sag isolation capability of DC link are analyzed in detail. The main limiting factors of the voltage sage isolation capability at the input and isolation stages with different design parameters are clarified. And the effective isolation area of cascaded PET is established. Finally, the correctness of research results is verified by simulation.关键词：voltage sag;power electronic transformer (PET);voltage sag isolation;input stage;isolation stage3|1|0更新时间：2025-06-16
- 摘要：Stray capacitance is an indeterminate factor affecting the harmonic measurement of capacitive voltage transformer (CVT). By analyzing the internal structure of CVT and the calculation formula of stray capacitance, it is found that the stray capacitance is a random interval-type parameter. In order to improve the fitting precision of harmonic transfer characteristic curve of CVT, this paper proposes a method based on improved particle swarm optimization (PSO) algorithm for parameter estimation of stray capacitance of CVT. The method takes the confidence interval of the input parameters as the condition, and the minimum error of calculation result as the goal. The parameter combination of the stray capacitance is determined under the condition that the requirements of the minimum errors of amplitude and phase shift are satisfied and the confidence intervals are as much as possible. Through the establishment of a comprehensive power quality test platform, the harmonic voltage value of the secondary side of a 35 kV resistive capacitive divider voltage transformer (RCVT) is used as a reference to analyze the error of the actual harmonic voltage value of the TYD35/
- 摘要：Aiming at the problems such as easy saturation of magnetic circuit and low acquired power of the widely used on-line power acquiring device of current transformer, this paper proposes an on-line power acquiring method combining dual magnetic circuit topology with resonant power control. In the dual magnetic circuit structure, a two-semicircle magnetic core is installed on the transmission line, and the excitation inductance in the magnetic circuit is resonant in parallel with the capacitance through the secondary-side connection capacitor, which increases the impedance value of the magnetic circuit. Thus, the current on the line is controlled to flow more into the other magnetic circuit coil of the dual magnetic circuit, through which the internal impedance is matched with the value of the external load, and the maximum power is obtained. Based on this method, an anti-saturation strategy of magnetic core controlled by excitation inductor and resonant capacitor is put forward, which makes the device keep high acquired power while work normally. The correctness of the method and the applicability for the circuit harmonic are verified by the joint simulation of Maxwell and Simplorer. The preliminary test shows that the power acquired by the dual magnetic circuit can meet the requirement of monitoring equipment of high voltage transmission line.关键词：on-line power acquiring;current transformer;parallel resonance;dual magnetic circuit;joint simulation3|0|0更新时间：2025-06-16
- 摘要：As the integration characteristics of power grid operation become prominent, the application business links between various levels of regulatory agencies are becoming increasingly close, and the demand for information sharing and data interaction is becoming more and more urgent. In order to achieve integrated and coordinated operation, the power grid dispatch and control system needs to interact with a large number of real-time data and non-real-time data between different regulatory agencies and business applications. However, the current technical scheme is mainly aimed at the data interaction between real-time services, and there is no universal data interaction mechanism in quasi-real-time/non-real-time business scenarios. Aiming at the above problem, this paper puts forward the regulation of business oriented, quasi-real-time/non-real-time data across institutions and across the safe zone, cross-platform integrated exchange of architecture, the establishment of a canonical data interaction processes and operation mechanism based on task, to realize unified management of data interaction process. At present, the research results have been applied in engineering to support the integrated and coordinated business of provincial, regional dispatch centers and substations.关键词：integrated coordination;task scheduling management;task trajectory monitoring;fault switching;data exchange3|1|0更新时间：2025-06-16
Application Research
- 摘要：Omnidirectional wireless power transfer technology is widely concerned by domestic and foreign research institutions and research institutes due to its unique advantages such as good location robustness, high safety and reliability, and strong environmental affinity. Firstly, the application field of omnidirectional wireless power transfer technology and the domestic and foreign development are described. Then, key fundamental problems of the electromagnetic coupling system are analyzed in detail, including the design and optimization of electromagnetic coupling structure, magnetic field direction control strategy and electromagnetic compatibility. Finally, key problems and technical difficulties in engineering, productization and commercialization of the technology are discussed, and its application prospect is further prospected.关键词：omnidirectional wireless power transfer;electromagnetic coupling structure;control strategy;electromagnetic compatibility3|0|0更新时间：2025-06-16
Review
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