In wind power transmission via modular multilevel converter based high voltage direct current(MMCHVDC)systems,under traditional control strategies,MMC-HVDCcannot provide inertia support to the receiving-end grid(REG)d...In wind power transmission via modular multilevel converter based high voltage direct current(MMCHVDC)systems,under traditional control strategies,MMC-HVDCcannot provide inertia support to the receiving-end grid(REG)during disturbances.Moreover,due to the frequency decoupling between the two ends of the MMCHVDC,the sending-end wind farm(SEWF)cannot obtain the frequency variation information of the REG to provide inertia response.Therefore,this paper proposes a novel coordinated source-network-storage inertia control strategy based on wind power transmission via MMC-HVDC system.First,the grid-side MMC station(GS-MMC)maps the frequency variations of the REG to direct current(DC)voltage variations through the frequency mapping control,and uses submodule capacitor energy to provide inertial power.Then,the wind farm-side MMC station(WF-MMC)restores the DC voltage variations to frequency variations through the frequency restoration control and power loss compensation,providing real-time frequency information for the wind farm.Finally,based on real-time frequency information,thewind farmutilizes the rotor kinetic energy and energy storage to provide fast and lasting power support through the wind-storage coordinated inertia control strategy.Meanwhile,when the wind turbines withdraw from the inertia response phase,the energy storage can increase the power output to compensate for the power deficit,preventing secondary frequency drops.Furthermore,this paper uses small-signal analysis to determine the appropriate values for the key parameters of the proposed control strategy.A simulation model of the wind power transmission via MMCHVDC system is built in MATLAB/Simulink environment to validate and evaluate the proposed method.The results show that the proposed coordinated control strategy can effectively improve the system inertia level and avoid the secondary frequency drop under the load sudden increase condition.展开更多
In remote areas far from the grid, wind/PV/storage generating system is relatively a good choice, whatever in resource configuration, performance or prices. For the independent hybrid power system, the output models o...In remote areas far from the grid, wind/PV/storage generating system is relatively a good choice, whatever in resource configuration, performance or prices. For the independent hybrid power system, the output models of wind turbines, photovoltaic arrays and batteries are built in this paper, and based on the objectives of the capacity configuration optimal model, constraints used in the process of capacity configuration are analyzed. These provide convenient conditions and theoretical basis for the optimal capacity configuration of independent wind/PV/storage system.展开更多
To address operational challenges such as reduced grid inertia and intensified power fluctuations caused by high renewable energy penetration,this paper systematically introduces the coordinated optimization and stabi...To address operational challenges such as reduced grid inertia and intensified power fluctuations caused by high renewable energy penetration,this paper systematically introduces the coordinated optimization and stability control technologies for wind-solar-storage smart grids.A three-tier time-scale(“day-ahead-intraday-real-time”)collaborative optimization framework was established,demonstrating a multi-objective dispatch model integrating electricity markets and frequency regulation auxiliary services to achieve synergistic improvement in economic benefits and renewable energy integration.After that,a hierarchical coordinated control strategy for hybrid energy storage was analyzed,where adaptive filtering algorithms decompose power commands into low-frequency energy components and high-frequency power components,which are respectively responded to by lithium batteries and supercapacitors,enabling organic integration of system-level dispatch and device-level control.Simulation results from a 300MW wind-solar-storage demonstration project in Northwest China show that the proposed strategy can increase the total revenue of combined power plants by approximately 22%while reducing curtailment rates by 8%.In terms of power fluctuation mitigation,the grid-connected power fluctuation rate is controlled within±2%,and frequency deviations are maintained within the safe range of±0.1 Hz.The research findings provide technical support for the safe and stable operation of high-renewable grids and hold significant engineering application value.展开更多
In the process of wind power,coal power,and energy storage equipment participating in the operation of industrial microgrids,the stable operation of wind-storage industrial microgrids is guaranteed by considering dema...In the process of wind power,coal power,and energy storage equipment participating in the operation of industrial microgrids,the stable operation of wind-storage industrial microgrids is guaranteed by considering demand response technology and user satisfaction.This paper firstly sorts out the status quo of microgrid operation optimization,and determines themain requirements for user satisfaction considering three types of load characteristics,demand response technology,power consumption benefit loss,user balance power purchase price and wind power consumption evaluation indicators in the system.Secondly,the operation architecture of the windstorage industrialmicrogrid is designed,and themulti-objective optimizationmodel of the wind-storage industrial microgrid is established with the comprehensive operating cost and user satisfaction as the target variables,and the corresponding solution method is mentioned.Finally,a typical wind-storage industrial microgrid is selected for simulation analysis,and the results showthat,(1)Considering the demand response technology,the comprehensive operating cost of the wind-storage industrial microgrid per day is 5292.63 yuan,the user satisfaction index is 0.953,and the wind power consumption rate reaches 100%.(2)By setting four scenarios,it highlights that the grid-connected operation mode is superior to the off-grid operation mode.Considering the demand response technology,the load curve can be optimized,and the time-of-use electricity price can be fully used to coordinate the operation of each unit,which enhances the wind power consumption capacity.The compromise solution of the system comprehensive operating cost and user satisfaction under the confidence level of 0.95 is obtained,namely(5343.22,0.94).(3)The frontier curve shows that in the process of model solving,it is impossible to optimize any sub-objective by changing the control variables,which proves that there is a close relationship between the comprehensive operating cost of the system and the confidence level,which can provide effective guidance for the optimal operation of industrial microgrids.展开更多
To improve the living standards,economical efficiency and environmental protection of isolated islands,remote areas and other areas with weak electric power facilities construction,a multi-source independent microgrid...To improve the living standards,economical efficiency and environmental protection of isolated islands,remote areas and other areas with weak electric power facilities construction,a multi-source independent microgrid system is studied,including diesel generators,photovoltaic power generation system,wind power generation system and energy storage unit.Meanwhile,in order to realize the voltage and frequency stability control of AC bus of multisource microgrid,the virtual synchronous generator technology is introduced into the energy storage unit,and the charge and discharge control of the energy storage battery are simulated as the control behavior characteristics of synchronous motors,so as to provide damping and inertia support for the microgrid.The operation mode and control principle of each energy subsystem are expounded and analyzed.The algorithm principle of virtual synchronous generator and the control method of energy storage unit are given.Then,the working modes of the microgrid system under different environmental conditions are analyzed,and the multi-source microgrid system simulation model is built based on MATLAB/Simulink.The simulation results show that the microgrid system can run stably under different working modes and the energy storage unit using the virtual synchronous generator technology can provide good voltage and frequency support for the microgrid system.Finally,experiments verify the supporting function of energy storage unit on the voltage and frequency of the microgrid system.展开更多
基金funded by State Grid Corporation of China Central Branch Technology Project(52140024000C).
文摘In wind power transmission via modular multilevel converter based high voltage direct current(MMCHVDC)systems,under traditional control strategies,MMC-HVDCcannot provide inertia support to the receiving-end grid(REG)during disturbances.Moreover,due to the frequency decoupling between the two ends of the MMCHVDC,the sending-end wind farm(SEWF)cannot obtain the frequency variation information of the REG to provide inertia response.Therefore,this paper proposes a novel coordinated source-network-storage inertia control strategy based on wind power transmission via MMC-HVDC system.First,the grid-side MMC station(GS-MMC)maps the frequency variations of the REG to direct current(DC)voltage variations through the frequency mapping control,and uses submodule capacitor energy to provide inertial power.Then,the wind farm-side MMC station(WF-MMC)restores the DC voltage variations to frequency variations through the frequency restoration control and power loss compensation,providing real-time frequency information for the wind farm.Finally,based on real-time frequency information,thewind farmutilizes the rotor kinetic energy and energy storage to provide fast and lasting power support through the wind-storage coordinated inertia control strategy.Meanwhile,when the wind turbines withdraw from the inertia response phase,the energy storage can increase the power output to compensate for the power deficit,preventing secondary frequency drops.Furthermore,this paper uses small-signal analysis to determine the appropriate values for the key parameters of the proposed control strategy.A simulation model of the wind power transmission via MMCHVDC system is built in MATLAB/Simulink environment to validate and evaluate the proposed method.The results show that the proposed coordinated control strategy can effectively improve the system inertia level and avoid the secondary frequency drop under the load sudden increase condition.
文摘In remote areas far from the grid, wind/PV/storage generating system is relatively a good choice, whatever in resource configuration, performance or prices. For the independent hybrid power system, the output models of wind turbines, photovoltaic arrays and batteries are built in this paper, and based on the objectives of the capacity configuration optimal model, constraints used in the process of capacity configuration are analyzed. These provide convenient conditions and theoretical basis for the optimal capacity configuration of independent wind/PV/storage system.
文摘To address operational challenges such as reduced grid inertia and intensified power fluctuations caused by high renewable energy penetration,this paper systematically introduces the coordinated optimization and stability control technologies for wind-solar-storage smart grids.A three-tier time-scale(“day-ahead-intraday-real-time”)collaborative optimization framework was established,demonstrating a multi-objective dispatch model integrating electricity markets and frequency regulation auxiliary services to achieve synergistic improvement in economic benefits and renewable energy integration.After that,a hierarchical coordinated control strategy for hybrid energy storage was analyzed,where adaptive filtering algorithms decompose power commands into low-frequency energy components and high-frequency power components,which are respectively responded to by lithium batteries and supercapacitors,enabling organic integration of system-level dispatch and device-level control.Simulation results from a 300MW wind-solar-storage demonstration project in Northwest China show that the proposed strategy can increase the total revenue of combined power plants by approximately 22%while reducing curtailment rates by 8%.In terms of power fluctuation mitigation,the grid-connected power fluctuation rate is controlled within±2%,and frequency deviations are maintained within the safe range of±0.1 Hz.The research findings provide technical support for the safe and stable operation of high-renewable grids and hold significant engineering application value.
文摘In the process of wind power,coal power,and energy storage equipment participating in the operation of industrial microgrids,the stable operation of wind-storage industrial microgrids is guaranteed by considering demand response technology and user satisfaction.This paper firstly sorts out the status quo of microgrid operation optimization,and determines themain requirements for user satisfaction considering three types of load characteristics,demand response technology,power consumption benefit loss,user balance power purchase price and wind power consumption evaluation indicators in the system.Secondly,the operation architecture of the windstorage industrialmicrogrid is designed,and themulti-objective optimizationmodel of the wind-storage industrial microgrid is established with the comprehensive operating cost and user satisfaction as the target variables,and the corresponding solution method is mentioned.Finally,a typical wind-storage industrial microgrid is selected for simulation analysis,and the results showthat,(1)Considering the demand response technology,the comprehensive operating cost of the wind-storage industrial microgrid per day is 5292.63 yuan,the user satisfaction index is 0.953,and the wind power consumption rate reaches 100%.(2)By setting four scenarios,it highlights that the grid-connected operation mode is superior to the off-grid operation mode.Considering the demand response technology,the load curve can be optimized,and the time-of-use electricity price can be fully used to coordinate the operation of each unit,which enhances the wind power consumption capacity.The compromise solution of the system comprehensive operating cost and user satisfaction under the confidence level of 0.95 is obtained,namely(5343.22,0.94).(3)The frontier curve shows that in the process of model solving,it is impossible to optimize any sub-objective by changing the control variables,which proves that there is a close relationship between the comprehensive operating cost of the system and the confidence level,which can provide effective guidance for the optimal operation of industrial microgrids.
基金supported by the Science and Technology Research&Development Project of China Construction Second Engineering Bureau Ltd.(No.91110000100024296D180009)。
文摘To improve the living standards,economical efficiency and environmental protection of isolated islands,remote areas and other areas with weak electric power facilities construction,a multi-source independent microgrid system is studied,including diesel generators,photovoltaic power generation system,wind power generation system and energy storage unit.Meanwhile,in order to realize the voltage and frequency stability control of AC bus of multisource microgrid,the virtual synchronous generator technology is introduced into the energy storage unit,and the charge and discharge control of the energy storage battery are simulated as the control behavior characteristics of synchronous motors,so as to provide damping and inertia support for the microgrid.The operation mode and control principle of each energy subsystem are expounded and analyzed.The algorithm principle of virtual synchronous generator and the control method of energy storage unit are given.Then,the working modes of the microgrid system under different environmental conditions are analyzed,and the multi-source microgrid system simulation model is built based on MATLAB/Simulink.The simulation results show that the microgrid system can run stably under different working modes and the energy storage unit using the virtual synchronous generator technology can provide good voltage and frequency support for the microgrid system.Finally,experiments verify the supporting function of energy storage unit on the voltage and frequency of the microgrid system.
