With the increase in the power receiving proportion and an insufficient peak regulation capacity of the local units, the receiving-end power grid struggles to achieve peak regulation in valley time. To solve this prob...With the increase in the power receiving proportion and an insufficient peak regulation capacity of the local units, the receiving-end power grid struggles to achieve peak regulation in valley time. To solve this problem while considering the potential of the large-scale charge load of electric vehicles(EVs), an aggregator-based demand response(DR) mechanism for EVs that are participating in the peak regulation in valley time is proposed in this study. In this aggregator-based DR mechanism, the profits for the power grid’s operation and the participation willingness of the EV owners are considered. Based on the characteristics of the EV charging process and the day-ahead unit generation scheduling, a rolling unit commitment model with the DR is established to maximize the social welfare. In addition, to improve the efficiency of the optimization problem solving process and to achieve communication between the independent system operator(ISO) and the aggregators, the clustering algorithm is utilized to extract typical EV charging patterns. Finally, the feasibility and benefits of the aggregator-based DR mechanism for saving the costs and reducing the peak-valley difference of the receiving-end power grid are verified through case studies.展开更多
Due to the shortage of fossil energy and the pollution caused by combustion of fossil fuels,the proportion of renewable energy in power systems is gradually increasing across the world.Accordingly,the capacity of powe...Due to the shortage of fossil energy and the pollution caused by combustion of fossil fuels,the proportion of renewable energy in power systems is gradually increasing across the world.Accordingly,the capacity of power systems to accommodate renewable energy must be improved.However,integration of a large amount of renewable energy into power grids may result in network congestion.Hence,in this study,optimal transmission switching(OTS)is considered as an important method of accommodating renewable energy.It is incorporated into the operation of a power grid along with deep peak regulation of thermal power units,forming an interactive mode of coordinated operation of source and network.A stochastic unit commitment model consider!ng deep peak regulation and OTS is established,and the role of OTS in promoting the accommodation of renewable energy is analyzed quantitatively.The results of case studies involving the IEEE 30-bus system demonstrate that OTS can enable utilization of the potential of deep peak regulation and facilitate the accommodation of renewable energy.展开更多
Existing swirling combustion technology,which relies on faulty coal,is unable to meet deep peak shaving demands without auxiliary methods.This paper developed a deep peak regulation burner(DPRB)to achieve stable combu...Existing swirling combustion technology,which relies on faulty coal,is unable to meet deep peak shaving demands without auxiliary methods.This paper developed a deep peak regulation burner(DPRB)to achieve stable combustion at 15%–30%of the boiler’s rated load without auxiliary support.Gas-particle tests,industrial trials,and transient numerical simulations were conducted to evaluate the burner’s performance.At full rated load,the DPRB formed a central recirculation zone(RZ)with a length of 1.5d and a diameter of 0.58d(where d represents the outlet diameter).At 40%,20%,and 15%rated loads,the RZ became annular,with diameters of 0.30d,0.40d,and 0.39d,respectively,with a length of 1.0d.At 20%and 15%rated loads,the recirculation peak and the range of particle volume flux were comparable to those at 40%rated load.The prototype burner demonstrated that,without oil support,the gas temperature within 0 to 1.8 m from the primary air outlet remained below 609℃,insufficient to ignite faulty coal.As the load rate increased from 20%to 30%,the prototype’s central region temperature remained low,with a maximum of 750℃between 0 and 2.0 m.In contrast,the DPRB’s central region temperature reached 750℃at around 0.65–0.70 m.At a 3%·min^(−1)load-up rate,when the load increased from 20%to 30%,the prototype burner extinguished after 30 s.However,the DPRB maintained stable combustion throughout the process.展开更多
With the rapid development of the installed capacity of clean energy sources such as wind power, hydropower and photovoltaic, significant changes have taken place in the domestic power structure, and deep peak-shaving...With the rapid development of the installed capacity of clean energy sources such as wind power, hydropower and photovoltaic, significant changes have taken place in the domestic power structure, and deep peak-shaving operation of large thermal power units has become the norm. When the depth of the unit reaches a lower load, the once-through boiler changes from dry to wet operation, and the water separated from the boiler steam-water separator directly enters the condenser or is discharged through the blowdown system, resulting in a large amount of discharge and heat loss. As a result, the operating economy of the unit decreased significantly.展开更多
In northern China,thermal power units(TPUs)are important in improving the penetration level of renewable energy.In such areas,the potentials of coordinated dispatch of renewable energy sources(RESs)and TPUs can be bet...In northern China,thermal power units(TPUs)are important in improving the penetration level of renewable energy.In such areas,the potentials of coordinated dispatch of renewable energy sources(RESs)and TPUs can be better realized,if RESs and TPUs connected to the power grid at the same point of common coupling(PCC)are dispatched as a coupled system.Firstly,the definition of the coupled system is introduced,followed by an analysis on its characteristics.Secondly,based on the operation characteristics of deep peak regulation(DPR)of TPUs in the coupled system,the constraint of the ladder-type ramping rate applicable for day-ahead dispatch is proposed,and the corresponding flexible spinning reserve constraint is further established.Then,considering these constraints and peak regulation ancillary services,a day-ahead optimal dispatch model of the coupled system is established.Finally,the operational characteristics and advantages of the coupled system are analyzed in several case studies based on a real-world power grid in Liaoning province,China.The numerical results show that the coupled system can further improve the economic benefits of RESs and TPUs under the existing policies.展开更多
Regarding the carbon neutrality target,the proportion of renewable energy in global energy sources is predicted to increase to 50%by 2050,and the increment in penetration requires fossil fuel power plants to play a ke...Regarding the carbon neutrality target,the proportion of renewable energy in global energy sources is predicted to increase to 50%by 2050,and the increment in penetration requires fossil fuel power plants to play a key role in grid peak regulation.The integrated gasification combined cycle(IGCC)is a promising peak-regulating method for power grids.However,due to the strong coupling between units,the flexibility of gas turbines cannot be fully utilized in response to power demand.This paper proposed a novel polygeneration system integrating syngas storage,hydrogen production,and gas turbines for power.Through syngas storage,the dynamic characteristic of each unit can be decoupled to take advantage of the flexibility of the gas turbine.Compared to the general IGCC system,the load change rate of the new system could be increased from 0.5%/min to 3-5%/min without altering the dynamic characteristics of the original equipment.The design capacity of the syngas storage tank could be reduced by decreasing the ramp rate of the power generation unit or increasing the load change rate of the gasification and hydrogen production units.For the new 300-MW system,the required syngas storage tank capacity reached only approximately 1872 m^(3) under storage conditions of 35 bar and 25℃.Furthermore,the investment in the syngas storage tank only accounted for approximately 6.6%of the total investment cost.In general,the novel system can be more flexibly operated under variable loads with low carbon emissions,which can help to increase the penetration of renewable energy in the power grid.展开更多
基金supported by the Science and Technology Project from the State Grid Shanghai Municipal Electric Power Company of China (52094019006U)the Shanghai Rising-Star Program (18QB1400200)。
文摘With the increase in the power receiving proportion and an insufficient peak regulation capacity of the local units, the receiving-end power grid struggles to achieve peak regulation in valley time. To solve this problem while considering the potential of the large-scale charge load of electric vehicles(EVs), an aggregator-based demand response(DR) mechanism for EVs that are participating in the peak regulation in valley time is proposed in this study. In this aggregator-based DR mechanism, the profits for the power grid’s operation and the participation willingness of the EV owners are considered. Based on the characteristics of the EV charging process and the day-ahead unit generation scheduling, a rolling unit commitment model with the DR is established to maximize the social welfare. In addition, to improve the efficiency of the optimization problem solving process and to achieve communication between the independent system operator(ISO) and the aggregators, the clustering algorithm is utilized to extract typical EV charging patterns. Finally, the feasibility and benefits of the aggregator-based DR mechanism for saving the costs and reducing the peak-valley difference of the receiving-end power grid are verified through case studies.
基金the National Natural Science Foundation of China(No.U1966204)the China State Key Lab.of Power System(SKJLD19KM09).
文摘Due to the shortage of fossil energy and the pollution caused by combustion of fossil fuels,the proportion of renewable energy in power systems is gradually increasing across the world.Accordingly,the capacity of power systems to accommodate renewable energy must be improved.However,integration of a large amount of renewable energy into power grids may result in network congestion.Hence,in this study,optimal transmission switching(OTS)is considered as an important method of accommodating renewable energy.It is incorporated into the operation of a power grid along with deep peak regulation of thermal power units,forming an interactive mode of coordinated operation of source and network.A stochastic unit commitment model consider!ng deep peak regulation and OTS is established,and the role of OTS in promoting the accommodation of renewable energy is analyzed quantitatively.The results of case studies involving the IEEE 30-bus system demonstrate that OTS can enable utilization of the potential of deep peak regulation and facilitate the accommodation of renewable energy.
基金supported by the Heilongjiang Touyan Innovation Team Program and the National Key Research and Development Program,China(No.2024YFB4104803).
文摘Existing swirling combustion technology,which relies on faulty coal,is unable to meet deep peak shaving demands without auxiliary methods.This paper developed a deep peak regulation burner(DPRB)to achieve stable combustion at 15%–30%of the boiler’s rated load without auxiliary support.Gas-particle tests,industrial trials,and transient numerical simulations were conducted to evaluate the burner’s performance.At full rated load,the DPRB formed a central recirculation zone(RZ)with a length of 1.5d and a diameter of 0.58d(where d represents the outlet diameter).At 40%,20%,and 15%rated loads,the RZ became annular,with diameters of 0.30d,0.40d,and 0.39d,respectively,with a length of 1.0d.At 20%and 15%rated loads,the recirculation peak and the range of particle volume flux were comparable to those at 40%rated load.The prototype burner demonstrated that,without oil support,the gas temperature within 0 to 1.8 m from the primary air outlet remained below 609℃,insufficient to ignite faulty coal.As the load rate increased from 20%to 30%,the prototype’s central region temperature remained low,with a maximum of 750℃between 0 and 2.0 m.In contrast,the DPRB’s central region temperature reached 750℃at around 0.65–0.70 m.At a 3%·min^(−1)load-up rate,when the load increased from 20%to 30%,the prototype burner extinguished after 30 s.However,the DPRB maintained stable combustion throughout the process.
文摘With the rapid development of the installed capacity of clean energy sources such as wind power, hydropower and photovoltaic, significant changes have taken place in the domestic power structure, and deep peak-shaving operation of large thermal power units has become the norm. When the depth of the unit reaches a lower load, the once-through boiler changes from dry to wet operation, and the water separated from the boiler steam-water separator directly enters the condenser or is discharged through the blowdown system, resulting in a large amount of discharge and heat loss. As a result, the operating economy of the unit decreased significantly.
基金supported in part by the National Key Research and Development Program of China(No.2019YFB1505400).
文摘In northern China,thermal power units(TPUs)are important in improving the penetration level of renewable energy.In such areas,the potentials of coordinated dispatch of renewable energy sources(RESs)and TPUs can be better realized,if RESs and TPUs connected to the power grid at the same point of common coupling(PCC)are dispatched as a coupled system.Firstly,the definition of the coupled system is introduced,followed by an analysis on its characteristics.Secondly,based on the operation characteristics of deep peak regulation(DPR)of TPUs in the coupled system,the constraint of the ladder-type ramping rate applicable for day-ahead dispatch is proposed,and the corresponding flexible spinning reserve constraint is further established.Then,considering these constraints and peak regulation ancillary services,a day-ahead optimal dispatch model of the coupled system is established.Finally,the operational characteristics and advantages of the coupled system are analyzed in several case studies based on a real-world power grid in Liaoning province,China.The numerical results show that the coupled system can further improve the economic benefits of RESs and TPUs under the existing policies.
基金the Beijing Municipal Science and Technology Commission(No.Z211100004521006).
文摘Regarding the carbon neutrality target,the proportion of renewable energy in global energy sources is predicted to increase to 50%by 2050,and the increment in penetration requires fossil fuel power plants to play a key role in grid peak regulation.The integrated gasification combined cycle(IGCC)is a promising peak-regulating method for power grids.However,due to the strong coupling between units,the flexibility of gas turbines cannot be fully utilized in response to power demand.This paper proposed a novel polygeneration system integrating syngas storage,hydrogen production,and gas turbines for power.Through syngas storage,the dynamic characteristic of each unit can be decoupled to take advantage of the flexibility of the gas turbine.Compared to the general IGCC system,the load change rate of the new system could be increased from 0.5%/min to 3-5%/min without altering the dynamic characteristics of the original equipment.The design capacity of the syngas storage tank could be reduced by decreasing the ramp rate of the power generation unit or increasing the load change rate of the gasification and hydrogen production units.For the new 300-MW system,the required syngas storage tank capacity reached only approximately 1872 m^(3) under storage conditions of 35 bar and 25℃.Furthermore,the investment in the syngas storage tank only accounted for approximately 6.6%of the total investment cost.In general,the novel system can be more flexibly operated under variable loads with low carbon emissions,which can help to increase the penetration of renewable energy in the power grid.
