To achieve optimal configuration of switching devices in a power distribution system,this paper proposes a repulsive firefly algorithm-based optimal switching device placement method.In this method,the influence of te...To achieve optimal configuration of switching devices in a power distribution system,this paper proposes a repulsive firefly algorithm-based optimal switching device placement method.In this method,the influence of territorial repulsion during firefly courtship is considered.The algorithm is practically applied to optimize the position and quantity of switching devices,while avoiding its convergence to the local optimal solution.The experimental simulation results have showed that the proposed repulsive firefly algorithm is feasible and effective,with satisfying global search capability and convergence speed,holding potential applications in setting value calculation of relay protection and distribution network automation control.展开更多
The power electronic transformer(PET) has recently emerged as a type of power converter. It features the basic functions of power conversion and isolation as well as additional functions related to power quality contr...The power electronic transformer(PET) has recently emerged as a type of power converter. It features the basic functions of power conversion and isolation as well as additional functions related to power quality control. A novel PET for a distribution grid called a flexible power distribution unit is proposed in this paper, and the energy exchange mechanism between the network and the load is revealed. A 30 kW 600 VAC/220 VAC/110 VDC medium-frequency isolated prototype is developed and demonstrated. This paper also presents key control strategies of the PET for electrical distribution grid applications,especially under grid voltage disturbance conditions.Moreover, stability issues related to the grid-connected three-phase PET are discussed and verified with an impedance-based analysis. The PET prototype is tested, and it passes the voltage-disturbance ride-through function. The experimental results verify the power quality control abilities of the PET.展开更多
As synchronous generators(SGs)are gradually displaced by renewable energy sources(RESs),the frequency stability of power systems deteriorates because RESs,represented by utility-scale solar and wind power sources,do n...As synchronous generators(SGs)are gradually displaced by renewable energy sources(RESs),the frequency stability of power systems deteriorates because RESs,represented by utility-scale solar and wind power sources,do not provide the inertial response,primary frequency response,secondary frequency response,and tertiary frequency regulation.As a result,the remaining SGs may not be sufficient to maintain the power balance and frequency stability.The concept and control strategies of virtual synchronous generators(VSGs)enable the inverter-based wind and solar power sources to emulate the outer characteristics of traditional SGs and participate in the active power and frequency control of power systems.This paper focuses on the automatic generation control(AGC)with virtual synchronous renewables(VSRs).First,the VSR strategy that enables the RESs to participate in AGC is introduced.Second,based on the interval representation of uncertainty,the output of RES is transformed into two portions,i.e.,the dispatchable portion and the stochastic portion.In the dispatchable portion,the RESs can participate in AGC jointly with SGs.Accordingly,a security-constrained economic dispatch(SCED)model is built considering the RESs operating in VSR mode.Third,the solution strategy that employs the slack variables to acquire deterministic constraints is introduced.Finally,the proposed SCED model is solved based on the 6-bus and 39-bus systems.The results show that,compared with the maximum power point tracking(MPPT)mode,VSRs can participate in the active power and frequency control jointly with SGs,increase the maximum penetration level of RESs,and decrease the operating cost.展开更多
基金supported by the State Grid Science and Technology Project “Research on Technology System and Applications Scenarios of Artificial Intelligence in Power System” (No. SGZJ0000KXJS1800435)Key Technology Project of State Grid Shanghai Municipal Electric Power Company “Research and demonstration of Shanghai power grid reliability analysis platform”Key Technology Project of China Electric Power Research Institute “Research on setting calculation technology of power grid phase protection based on Artificial Intelligence” (JB83-19-007)
文摘To achieve optimal configuration of switching devices in a power distribution system,this paper proposes a repulsive firefly algorithm-based optimal switching device placement method.In this method,the influence of territorial repulsion during firefly courtship is considered.The algorithm is practically applied to optimize the position and quantity of switching devices,while avoiding its convergence to the local optimal solution.The experimental simulation results have showed that the proposed repulsive firefly algorithm is feasible and effective,with satisfying global search capability and convergence speed,holding potential applications in setting value calculation of relay protection and distribution network automation control.
基金supported in part by the National Basic Research Program of China(No.2016YFB0900404)the National Natural Science Foundation of China(No.51477030,No.51207023)+2 种基金the Cooperative Innovation Fund of Jiangsu Province–the Prospective and Joint Research Project(No.BY2015070-18)the Basic and Prospective Science and Technology Project of State Grid Corporation of China(No.PD71-17-024)the Fundamental Research Funds for the Central Universities(No.2242017K40159)
文摘The power electronic transformer(PET) has recently emerged as a type of power converter. It features the basic functions of power conversion and isolation as well as additional functions related to power quality control. A novel PET for a distribution grid called a flexible power distribution unit is proposed in this paper, and the energy exchange mechanism between the network and the load is revealed. A 30 kW 600 VAC/220 VAC/110 VDC medium-frequency isolated prototype is developed and demonstrated. This paper also presents key control strategies of the PET for electrical distribution grid applications,especially under grid voltage disturbance conditions.Moreover, stability issues related to the grid-connected three-phase PET are discussed and verified with an impedance-based analysis. The PET prototype is tested, and it passes the voltage-disturbance ride-through function. The experimental results verify the power quality control abilities of the PET.
基金supported by the Research and Application of Key Technologies of Flexible Power Supply System Under Various Emergency Scenarios(No.5442PD210001)。
文摘As synchronous generators(SGs)are gradually displaced by renewable energy sources(RESs),the frequency stability of power systems deteriorates because RESs,represented by utility-scale solar and wind power sources,do not provide the inertial response,primary frequency response,secondary frequency response,and tertiary frequency regulation.As a result,the remaining SGs may not be sufficient to maintain the power balance and frequency stability.The concept and control strategies of virtual synchronous generators(VSGs)enable the inverter-based wind and solar power sources to emulate the outer characteristics of traditional SGs and participate in the active power and frequency control of power systems.This paper focuses on the automatic generation control(AGC)with virtual synchronous renewables(VSRs).First,the VSR strategy that enables the RESs to participate in AGC is introduced.Second,based on the interval representation of uncertainty,the output of RES is transformed into two portions,i.e.,the dispatchable portion and the stochastic portion.In the dispatchable portion,the RESs can participate in AGC jointly with SGs.Accordingly,a security-constrained economic dispatch(SCED)model is built considering the RESs operating in VSR mode.Third,the solution strategy that employs the slack variables to acquire deterministic constraints is introduced.Finally,the proposed SCED model is solved based on the 6-bus and 39-bus systems.The results show that,compared with the maximum power point tracking(MPPT)mode,VSRs can participate in the active power and frequency control jointly with SGs,increase the maximum penetration level of RESs,and decrease the operating cost.