For China,one of its most important commitments is to realize its“3060”targets of achieving a CO_(2) emission peak by 2030 and carbon neutrality by 2060.However,for a developing country with heavy carbon utilization...For China,one of its most important commitments is to realize its“3060”targets of achieving a CO_(2) emission peak by 2030 and carbon neutrality by 2060.However,for a developing country with heavy carbon utilization,achieving carbon neutrality in a short period necessitates tough changes.This paper briefly introduces energy and electricity scenarios and analyzes the challenges based on the current power system in China.Moreover,it summarizes the six characteristics of China’s future power grid and highlights some partially representative projects in the country.展开更多
Energy storage batteries can smooth the volatility of renewable energy sources.The operating conditions during power grid integration of renewable energy can affect the performance and failure risk of battery energy s...Energy storage batteries can smooth the volatility of renewable energy sources.The operating conditions during power grid integration of renewable energy can affect the performance and failure risk of battery energy storage system(BESS).However,the current modeling of grid-connected BESS is overly simplistic,typically only considering state of charge(SOC)and power constraints.Detailed lithium(Li)-ion battery cell models are computationally intensive and impractical for real-time applications and may not be suitable for power grid operating conditions.Additionally,there is a lack of real-time batteries risk assessment frameworks.To address these issues,in this study,we establish a thermal-electric-performance(TEP)coupling model based on a multitime scale BESS model,incorporating the electrical and thermal characteristics of Li-ion batteries along with their performance degradation to achieve detailed simulation of grid-connected BESS.Additionally,considering the operating characteristics of energy storage batteries and electrical and thermal abuse factors,we developed a battery pack operational riskmodel,which takes into account SOCand charge-discharge rate(Cr),using amodified failure rate to represent the BESS risk.By integrating detailed simulation of energy storage with predictive failure risk analysis,we obtained a detailed model for BESS risk analysis.This model offers a multi-time scale integrated simulation that spans month-level energy storage simulation times,day-level performance degradation,minutescale failure rate,and second-level BESS characteristics.It offers a critical tool for the study of BESS.Finally,the performance and risk of energy storage batteries under three scenarios—microgrid energy storage,wind power smoothing,and power grid failure response—are simulated,achieving a real-time state-dependent operational risk analysis of the BESS.展开更多
Because of the large-scale integration of wind power,the dynamic characteristics of power system have many uncertain effects.Based on deterministic analysis methods,traditional on-line security assessment system canno...Because of the large-scale integration of wind power,the dynamic characteristics of power system have many uncertain effects.Based on deterministic analysis methods,traditional on-line security assessment system cannot quantitatively estimate the actual operating conditions of the power system for only considering the most serious and credible accidents.Therefore,the risk theory is introduced into an on-line security assessment system and then an on-line risk assessment system for wind power is designed and implemented by combining with the dynamic security assessment system.Based on multiple data integration,the wind power disturbance probability is available and the security assessment of the power grid can obtain security indices in different aspects.The operating risk index is an expectation of severity,computed by summing up all the products of the result probability and its severity.Analysis results are reported to the dispatchers in on-line environment,while the comprehensive weak links are automatically provided to the power dispatching center.The risk assessment system in operation can verify the reasonableness of the system.展开更多
In the last few decades, in the world and also in the European Union, considerable resources had been invested in the rapid development of renewable energy sources and distributed generation in general. At the same ti...In the last few decades, in the world and also in the European Union, considerable resources had been invested in the rapid development of renewable energy sources and distributed generation in general. At the same time, power consumption is continuously increasing, and consumers are becoming more complex, which ultimately requires new investments in the distribution network. Concept of smart grids is generally accepted as a possible solution. Smart grid is a concept with many elements, where monitoring and control of every element in the chain of production, transmission, distribution and final consumption enable much more efficient delivery and use of electricity. One of the elements of smart grid efficiency is the ability of real-time demand-supply balancing. This balancing is carried out by monitoring of consumption and redistribution of electricity among individual end users, according to their needs. The aim of this paper is creating algorithm for real-time load management using power measurements. Algorithm for real-time load management at the ETFOS （Faculty of Electrical Engineering in Osijek）, Croatia is created based on measurements of photovoltaic power plant production, the power consumption of air conditioning system and the faculty building total electricity consumption. Expected result of real-time re-dispatching of air conditioners consumption, depending on the level of electricity production in photovoltaic power plant is decreasing peak demand of the faculty.展开更多
The wind power generation is increasing in many countries as a result of decreasing technology costs, active government policies for renewable energy sources, environmental concerns, etc.. This paper investigates the ...The wind power generation is increasing in many countries as a result of decreasing technology costs, active government policies for renewable energy sources, environmental concerns, etc.. This paper investigates the impact of wind power generation on ATC （available transmission capacity） calculation. In order to determine the maximum incremental MW transfer possible between two parts of a power system without violating any specified limits, ATCs are calculated. When calculating ATC values, it is necessary to assume production and consumption pattern in power system. Production of wind power depends on the wind speed, which is a random variable and it is impossible to forecast exactly the production of wind power that is needed for the ATCs calculation. In order to investigate influence of the stochastic wind power production on the ATCs value, computer model of Croatian electric power system is made in Power World Simulator. ATCs are calculated for southern part of Croatian power system in which besides wind power, hydro power plants are only type of power generation. Available wind speed measurements are used as input data for wind power production. The results of the ATC calculation for different scenario of wind power production and location in the Southern Croatian power system are presented and discussed in the paper.展开更多
Due to the increasing amount of photovoltaic (PV)-based power generation being connected to power systems, issues pertaining to the integration of the PV-based generators have attracted intense attention. In this conn...Due to the increasing amount of photovoltaic (PV)-based power generation being connected to power systems, issues pertaining to the integration of the PV-based generators have attracted intense attention. In this connection, the design of a PV-based stabilizer for enhancing power system dynamic stability is examined. The damping action is achieved through the independent control of real power flow from the stabilizer and voltage at the point of common coupling between the stabilizer and grid system. The stabilizer system is designed based on classical frequency response technique. Robustness of the proposed control strategy in enhancing network dynamic stability is demonstrated through computer simulation.展开更多
When the authors research on the fact that some SVC （static var compensator） substations connected at some buses in power system, they realized that some main functions ensured to operate well. Those are： compensat...When the authors research on the fact that some SVC （static var compensator） substations connected at some buses in power system, they realized that some main functions ensured to operate well. Those are： compensate reactive power following value U＊ according to the requirements of the Vietnamese power system dispath center, flit harmonic by passive filter... However, it still has some disadvantages of this substation that need to be overcome： use large number of main devices, generate harmonics by itself, cause a lot of active power losses. Thus, the authors have an idea to solve these problems by applying a bidirectional power converter with having difference circuit structure and PWM （pulse width modulation） controller with SVM （space vector modulation） pulse generated section, so compensative current which is created by inductance element can be reserved, adjust continuos and always has full sinusoidal form, not generating harmonic. The benefit of this new solution is to eliminate the three above fundamental disadvantages. This new model is built based on authors＇ research about BESS （battery energy storage system）. The research results have been verified by simulations in Matlab/Simulink software.展开更多
With the rapid development of renewable energy,wind-thermal-bundled power transmission by line-commutated converter based high-voltage direct current(LCC-HVDC)systems has been widely developed.The dynamic interaction ...With the rapid development of renewable energy,wind-thermal-bundled power transmission by line-commutated converter based high-voltage direct current(LCC-HVDC)systems has been widely developed.The dynamic interaction mechanisms among permanent magnet synchronous generators(PMSGs),synchronous generators(SGs),and LCC-HVDC system become complex.To deal with this issue,a path analysis method(PAM)is proposed to study the dynamic interaction mechanism,and the damping reconstruction is used to analyze the damping characteristic of the system.First,based on the modular modeling,linearized models for the PMSG subsystem,the LCC-HVDC subsystem,and the SG subsystem are established.Second,based on the closed-loop transfer function diagram of the system,the disturbance transfer path and coupling relationship among subsystems are analyzed by the PAM,and the damping characteristic analysis of the SG-dominated oscillation mode is studied based on the damping reconstruction.Compared with the PAM,the small-signal model of the system is obtained and eigenvalue analysis results are presented.Then,the effect of the control parameters on the damping characteristic is analyzed and the conclusions are verified by time-domain simulations.Finally,the penalty functions of the oscillation modes and decay modes are taken as the objective function,and an optimization strategy based on the Monte Carlo method is proposed to solve the parameter optimization problem.Numerical simulation results are presented to validate the effectiveness of the proposed strategy.展开更多
Power grid simulation calculation iswidely used in fields such as power grid operation,planning,safety defense,and accident inversion,which is one of the fundamental support technologies for power grid operation.At pr...Power grid simulation calculation iswidely used in fields such as power grid operation,planning,safety defense,and accident inversion,which is one of the fundamental support technologies for power grid operation.At present,mainstream software for power grid simulation calculation used by domestic power grid enterprises include PSD Power Tools,Power System Analysis Software Package(PSASP),Advanced Digital Power System Simulator(ADPSS)and so on,which can provide various simulation calculation functions such as power flow calculation,transient stability calculation,short circuit current calculation,etc.But in the process of using these software,various calculation data adjustments still rely entirely on manual experience.This article introduces artificial intelligence technology into power grid simulation calculation and develops an intelligent power system analysis platform which can be used in the simulation for large power grids,achieving the combination of artificial intelligence technology and power grid simulation technology,which can provide technical support for the transformation of power grid simulation and analysis work mode.展开更多
The quality of methods for determining energy transits on the tie lines （lines that connect two neighboring power system） can have significant impact on business activity of the TSOs （transmission system operators...The quality of methods for determining energy transits on the tie lines （lines that connect two neighboring power system） can have significant impact on business activity of the TSOs （transmission system operators）. Existing law regulation is not enough precise regarding definition of methods for metering energy transits （energy interchanged between neighboring TSOs）. This paper analyses disadvantages of method for line losses metering with electric meters and suggests introduction of the measured value corrections.展开更多
Detailed procedures for the modeling of synthesis load models (SLM) of actual power network are presented, then the classification indices based on 1oad characteristics and the principle of load classification are exp...Detailed procedures for the modeling of synthesis load models (SLM) of actual power network are presented, then the classification indices based on 1oad characteristics and the principle of load classification are expounded. Based on the results of general investigation of 220 kV and 330kV substations in China’s power grid, the load characteristics are classified, and detailed load characteristic investigation of selected different kinds of typical substations are carried out. By use of statistical synthesis, the SLM for typical substations, in which the distribution networks are taken into account, are built;and the modeling results are disseminated and applied to whole Chinese power grid. Besides, the load model parameters are evaluated and verified via post-disturbance simulation method. The effectiveness of the built SLM is validated by the fitting of some disturbance incidents.展开更多
Wind-thermal-bundled system has emerged as the predominant type of power system,incorporating a significant proportion of renewable energy.The dynamic interaction mechanism of the system is complex,and the issue of os...Wind-thermal-bundled system has emerged as the predominant type of power system,incorporating a significant proportion of renewable energy.The dynamic interaction mechanism of the system is complex,and the issue of oscillation stability is significant.In this paper,the damping characteristics of the direct current(DC)capacitance oscillation mode are analyzed using the path analysis method(PAM).This method combines the transfer-function block diagram with the damping torque analysis(DTA).Firstly,the linear models of the permanent magnet synchronous generator(PMSG),the synchronous generator(SG),and the alternating current(AC)grid are established based on the transfer functions.The closed-loop transferfunction block diagram of the wind-thermal-bundled systems is derived.Secondly,the block diagram reveals the damping path and the dynamic interaction mechanism of the system.According to the superposition principle,the transfer-function block diagram is reconstructed to achieve the damping separation.The damping coefficient of the DTA is used to quantify the effect of the interaction between the subsystems on the damping characteristics of the oscillation mode.Then,the eigenvalue analysis is used to analyze the system stability.Finally,the damping characteristic analysis is validated by time-domain simulations.展开更多
Nowadays IPP＇s power plant construction is encouraged by the current deregulatory climate. The financing technique employed to implement these projects is often the project financing formula. Under such condition an ...Nowadays IPP＇s power plant construction is encouraged by the current deregulatory climate. The financing technique employed to implement these projects is often the project financing formula. Under such condition an investor consortium, usually foreigner plan, build, operate the power plant and sell the generated electricity to the host utility. The sale price is determined from the expected IPP＇s production cost, enhanced from the expected welfare obtainable by selling electricity. This paper proposes a methodology for linking the uncertainty of the future production cost with the price of the electricity generated by an IPP. This is a stochastic approach to the sale price definition problem, while usually conducted through a deterministic procedure.展开更多
基金supported by the SGCC(State Grid Corporation of China)technology project Analysis of System Stability Region and Control Strategy Based on Lyapunov Method(No.5100-202155304A-0-0-00).
文摘For China,one of its most important commitments is to realize its“3060”targets of achieving a CO_(2) emission peak by 2030 and carbon neutrality by 2060.However,for a developing country with heavy carbon utilization,achieving carbon neutrality in a short period necessitates tough changes.This paper briefly introduces energy and electricity scenarios and analyzes the challenges based on the current power system in China.Moreover,it summarizes the six characteristics of China’s future power grid and highlights some partially representative projects in the country.
基金Supported by Open Fund of National Key Laboratory of Power Grid Safety(No.XTB51202301386).
文摘Energy storage batteries can smooth the volatility of renewable energy sources.The operating conditions during power grid integration of renewable energy can affect the performance and failure risk of battery energy storage system(BESS).However,the current modeling of grid-connected BESS is overly simplistic,typically only considering state of charge(SOC)and power constraints.Detailed lithium(Li)-ion battery cell models are computationally intensive and impractical for real-time applications and may not be suitable for power grid operating conditions.Additionally,there is a lack of real-time batteries risk assessment frameworks.To address these issues,in this study,we establish a thermal-electric-performance(TEP)coupling model based on a multitime scale BESS model,incorporating the electrical and thermal characteristics of Li-ion batteries along with their performance degradation to achieve detailed simulation of grid-connected BESS.Additionally,considering the operating characteristics of energy storage batteries and electrical and thermal abuse factors,we developed a battery pack operational riskmodel,which takes into account SOCand charge-discharge rate(Cr),using amodified failure rate to represent the BESS risk.By integrating detailed simulation of energy storage with predictive failure risk analysis,we obtained a detailed model for BESS risk analysis.This model offers a multi-time scale integrated simulation that spans month-level energy storage simulation times,day-level performance degradation,minutescale failure rate,and second-level BESS characteristics.It offers a critical tool for the study of BESS.Finally,the performance and risk of energy storage batteries under three scenarios—microgrid energy storage,wind power smoothing,and power grid failure response—are simulated,achieving a real-time state-dependent operational risk analysis of the BESS.
基金supported by National High Technology Research and Development Program of China (863 Program) (No.2011AA05A118)
文摘Because of the large-scale integration of wind power,the dynamic characteristics of power system have many uncertain effects.Based on deterministic analysis methods,traditional on-line security assessment system cannot quantitatively estimate the actual operating conditions of the power system for only considering the most serious and credible accidents.Therefore,the risk theory is introduced into an on-line security assessment system and then an on-line risk assessment system for wind power is designed and implemented by combining with the dynamic security assessment system.Based on multiple data integration,the wind power disturbance probability is available and the security assessment of the power grid can obtain security indices in different aspects.The operating risk index is an expectation of severity,computed by summing up all the products of the result probability and its severity.Analysis results are reported to the dispatchers in on-line environment,while the comprehensive weak links are automatically provided to the power dispatching center.The risk assessment system in operation can verify the reasonableness of the system.
文摘In the last few decades, in the world and also in the European Union, considerable resources had been invested in the rapid development of renewable energy sources and distributed generation in general. At the same time, power consumption is continuously increasing, and consumers are becoming more complex, which ultimately requires new investments in the distribution network. Concept of smart grids is generally accepted as a possible solution. Smart grid is a concept with many elements, where monitoring and control of every element in the chain of production, transmission, distribution and final consumption enable much more efficient delivery and use of electricity. One of the elements of smart grid efficiency is the ability of real-time demand-supply balancing. This balancing is carried out by monitoring of consumption and redistribution of electricity among individual end users, according to their needs. The aim of this paper is creating algorithm for real-time load management using power measurements. Algorithm for real-time load management at the ETFOS （Faculty of Electrical Engineering in Osijek）, Croatia is created based on measurements of photovoltaic power plant production, the power consumption of air conditioning system and the faculty building total electricity consumption. Expected result of real-time re-dispatching of air conditioners consumption, depending on the level of electricity production in photovoltaic power plant is decreasing peak demand of the faculty.
文摘The wind power generation is increasing in many countries as a result of decreasing technology costs, active government policies for renewable energy sources, environmental concerns, etc.. This paper investigates the impact of wind power generation on ATC （available transmission capacity） calculation. In order to determine the maximum incremental MW transfer possible between two parts of a power system without violating any specified limits, ATCs are calculated. When calculating ATC values, it is necessary to assume production and consumption pattern in power system. Production of wind power depends on the wind speed, which is a random variable and it is impossible to forecast exactly the production of wind power that is needed for the ATCs calculation. In order to investigate influence of the stochastic wind power production on the ATCs value, computer model of Croatian electric power system is made in Power World Simulator. ATCs are calculated for southern part of Croatian power system in which besides wind power, hydro power plants are only type of power generation. Available wind speed measurements are used as input data for wind power production. The results of the ATC calculation for different scenario of wind power production and location in the Southern Croatian power system are presented and discussed in the paper.
文摘Due to the increasing amount of photovoltaic (PV)-based power generation being connected to power systems, issues pertaining to the integration of the PV-based generators have attracted intense attention. In this connection, the design of a PV-based stabilizer for enhancing power system dynamic stability is examined. The damping action is achieved through the independent control of real power flow from the stabilizer and voltage at the point of common coupling between the stabilizer and grid system. The stabilizer system is designed based on classical frequency response technique. Robustness of the proposed control strategy in enhancing network dynamic stability is demonstrated through computer simulation.
文摘When the authors research on the fact that some SVC （static var compensator） substations connected at some buses in power system, they realized that some main functions ensured to operate well. Those are： compensate reactive power following value U＊ according to the requirements of the Vietnamese power system dispath center, flit harmonic by passive filter... However, it still has some disadvantages of this substation that need to be overcome： use large number of main devices, generate harmonics by itself, cause a lot of active power losses. Thus, the authors have an idea to solve these problems by applying a bidirectional power converter with having difference circuit structure and PWM （pulse width modulation） controller with SVM （space vector modulation） pulse generated section, so compensative current which is created by inductance element can be reserved, adjust continuos and always has full sinusoidal form, not generating harmonic. The benefit of this new solution is to eliminate the three above fundamental disadvantages. This new model is built based on authors＇ research about BESS （battery energy storage system）. The research results have been verified by simulations in Matlab/Simulink software.
基金supported in part by the National Natural Science Foundation of China(No.U22B20109).
文摘With the rapid development of renewable energy,wind-thermal-bundled power transmission by line-commutated converter based high-voltage direct current(LCC-HVDC)systems has been widely developed.The dynamic interaction mechanisms among permanent magnet synchronous generators(PMSGs),synchronous generators(SGs),and LCC-HVDC system become complex.To deal with this issue,a path analysis method(PAM)is proposed to study the dynamic interaction mechanism,and the damping reconstruction is used to analyze the damping characteristic of the system.First,based on the modular modeling,linearized models for the PMSG subsystem,the LCC-HVDC subsystem,and the SG subsystem are established.Second,based on the closed-loop transfer function diagram of the system,the disturbance transfer path and coupling relationship among subsystems are analyzed by the PAM,and the damping characteristic analysis of the SG-dominated oscillation mode is studied based on the damping reconstruction.Compared with the PAM,the small-signal model of the system is obtained and eigenvalue analysis results are presented.Then,the effect of the control parameters on the damping characteristic is analyzed and the conclusions are verified by time-domain simulations.Finally,the penalty functions of the oscillation modes and decay modes are taken as the objective function,and an optimization strategy based on the Monte Carlo method is proposed to solve the parameter optimization problem.Numerical simulation results are presented to validate the effectiveness of the proposed strategy.
基金supported by the State Grid Corporation of China‘s project:Research on artificial intelligence analysis technology of available transmission capacity(ATC)of key section under multiple power grid operation modes(5100-202255020A-1-1-ZN).
文摘Power grid simulation calculation iswidely used in fields such as power grid operation,planning,safety defense,and accident inversion,which is one of the fundamental support technologies for power grid operation.At present,mainstream software for power grid simulation calculation used by domestic power grid enterprises include PSD Power Tools,Power System Analysis Software Package(PSASP),Advanced Digital Power System Simulator(ADPSS)and so on,which can provide various simulation calculation functions such as power flow calculation,transient stability calculation,short circuit current calculation,etc.But in the process of using these software,various calculation data adjustments still rely entirely on manual experience.This article introduces artificial intelligence technology into power grid simulation calculation and develops an intelligent power system analysis platform which can be used in the simulation for large power grids,achieving the combination of artificial intelligence technology and power grid simulation technology,which can provide technical support for the transformation of power grid simulation and analysis work mode.
文摘The quality of methods for determining energy transits on the tie lines （lines that connect two neighboring power system） can have significant impact on business activity of the TSOs （transmission system operators）. Existing law regulation is not enough precise regarding definition of methods for metering energy transits （energy interchanged between neighboring TSOs）. This paper analyses disadvantages of method for line losses metering with electric meters and suggests introduction of the measured value corrections.
文摘Detailed procedures for the modeling of synthesis load models (SLM) of actual power network are presented, then the classification indices based on 1oad characteristics and the principle of load classification are expounded. Based on the results of general investigation of 220 kV and 330kV substations in China’s power grid, the load characteristics are classified, and detailed load characteristic investigation of selected different kinds of typical substations are carried out. By use of statistical synthesis, the SLM for typical substations, in which the distribution networks are taken into account, are built;and the modeling results are disseminated and applied to whole Chinese power grid. Besides, the load model parameters are evaluated and verified via post-disturbance simulation method. The effectiveness of the built SLM is validated by the fitting of some disturbance incidents.
基金supported in part by National Key R&D Program of China(No.2022YFB2403100)。
文摘Wind-thermal-bundled system has emerged as the predominant type of power system,incorporating a significant proportion of renewable energy.The dynamic interaction mechanism of the system is complex,and the issue of oscillation stability is significant.In this paper,the damping characteristics of the direct current(DC)capacitance oscillation mode are analyzed using the path analysis method(PAM).This method combines the transfer-function block diagram with the damping torque analysis(DTA).Firstly,the linear models of the permanent magnet synchronous generator(PMSG),the synchronous generator(SG),and the alternating current(AC)grid are established based on the transfer functions.The closed-loop transferfunction block diagram of the wind-thermal-bundled systems is derived.Secondly,the block diagram reveals the damping path and the dynamic interaction mechanism of the system.According to the superposition principle,the transfer-function block diagram is reconstructed to achieve the damping separation.The damping coefficient of the DTA is used to quantify the effect of the interaction between the subsystems on the damping characteristics of the oscillation mode.Then,the eigenvalue analysis is used to analyze the system stability.Finally,the damping characteristic analysis is validated by time-domain simulations.
文摘Nowadays IPP＇s power plant construction is encouraged by the current deregulatory climate. The financing technique employed to implement these projects is often the project financing formula. Under such condition an investor consortium, usually foreigner plan, build, operate the power plant and sell the generated electricity to the host utility. The sale price is determined from the expected IPP＇s production cost, enhanced from the expected welfare obtainable by selling electricity. This paper proposes a methodology for linking the uncertainty of the future production cost with the price of the electricity generated by an IPP. This is a stochastic approach to the sale price definition problem, while usually conducted through a deterministic procedure.
