The emerging novel energy infrastructures,such as energy communities,smart building-based microgrids,electric vehicles enabled mobile energy storage units raise the requirements for a more interconnective and interope...The emerging novel energy infrastructures,such as energy communities,smart building-based microgrids,electric vehicles enabled mobile energy storage units raise the requirements for a more interconnective and interoperable energy system.It leads to a transition from simple and isolated microgrids to relatively large-scale and complex interconnected microgrid systems named multi-microgrid clusters.In order to efficiently,optimally,and flexibly control multi-microgrid clusters,cross-disciplinary technologies such as power electronics,control theory,optimization algorithms,information and communication technologies,cyber-physical,and big-data analysis are needed.This paper introduces an overview of the relevant aspects for multi-microgrids,including the out-standing features,architectures,typical applications,existing control mechanisms,as well as the challenges.展开更多
Syncope belongs to the transient loss of consciousness(TLOC), characterized by a rapid onset, short duration, and spontaneous complete recovery. It is common in children and adolescents, accounting for 1% to 2% of eme...Syncope belongs to the transient loss of consciousness(TLOC), characterized by a rapid onset, short duration, and spontaneous complete recovery. It is common in children and adolescents, accounting for 1% to 2% of emergency department visits.Recurrent syncope can seriously affect children's physical and mental health, learning ability and quality of life and sometimes cardiac syncope even poses a risk of sudden death. The present guideline for the diagnosis and treatment of syncope in children and adolescents was developed for guiding a better clinical management of pediatric syncope. Based on the globally recent development and the evidence-based data in China, 2018 Chinese Pediatric Cardiology Society(CPCS) guideline for diagnosis and treatment of syncope in children and adolescents was jointly prepared by the Pediatric Cardiology Society, Chinese Pediatric Society, Chinese Medical Association(CMA)/Committee on Pediatric Syncope, Pediatricians Branch, Chinese Medical Doctor Association(CMDA)/Committee on Pediatric Cardiology, Chinese College of Cardiovascular Physicians, Chinese Medical Doctor Association(CMDA)/Pediatric Cardiology Society, Beijing Pediatric Society, Beijing Medical Association(BMA). The present guideline includes the underlying diseases of syncope in children and adolescents, the diagnostic procedures, methodology and clinical significance of standing test and headup tilt test, the clinical diagnosis vasovagal syncope, postural orthostatic tachycardia syndrome, orthostatic hypotension and orthostatic hypertension, and the treatment of syncope as well as follow-up.展开更多
This paper proposes a fast coordinated power control method based on two augmented channels(AC)in battery energy storage system(BESS)to improve inertial and voltage support capability,i.e.,a frequency-reactive power c...This paper proposes a fast coordinated power control method based on two augmented channels(AC)in battery energy storage system(BESS)to improve inertial and voltage support capability,i.e.,a frequency-reactive power channel(FRPC)and a voltage-real power channel(VRPC).For frequency control in the power distribution system with high resistance/inductance ratio,the coupling mechanism between rate of change of frequency(RoCoF)and required reactive power(RRP)of grids is analyzed,indicating RoCoF is proportional to RRP.Thus,RoCoF is utilized in FRPC to generate reactive power for complementary inertial emulating control.Meanwhile,for voltage control,coupling characteristics between rate of change of voltage(RoCoV)and demanding real power(DRP)of grids is also studied,revealing RoCoV is proportional to DRP.Therefore,it can be adopted in VRPC to generate real power for complementary voltage control.Then,grid-voltage-modulated direct power control is selected as the inner power control loop to track power references with faster dynamic performance compared with traditional vector-oriented control.Finally,simulations and hardware-in-loop experiments validate improvement in performance of grid frequency and voltage control based on the proposed method.展开更多
An exponential-function-based droop control strategy for the distributed energy resources(DERs)is proposed to reduce the reactive power-sharing deviation,limit the minimum value of frequency/voltage,whilst improving t...An exponential-function-based droop control strategy for the distributed energy resources(DERs)is proposed to reduce the reactive power-sharing deviation,limit the minimum value of frequency/voltage,whilst improving the utilization rate of renewable energy.Both DERs and loads are interconnected to achieve a power exchange by converters,where the power management system should accurately share the active/reactive power demand.However,the proportional reactive power sharing often deteriorates due to its dependence on the line impedances.Thus,an exponential-function-based droop control is proposed to(1)prevent voltage and frequency from falling to the lower restraint,(2)achieve accurate reactive power sharing,(3)eliminate communication and improve the usage ratio of renewable energy.Furthermore,its stability is analyzed,and the application in islanded AC/DC hybrid microgrids is investigated to achieve the bidirectional power flow.The simulation and experimental results show that the reactive power sharing deviation can be reduced,and the utilization rate of renewable energy is improved by using the proposed method.Moreover,the simulation results illustrate that the system can maintain stable operation when the microgrid is switched from one supplied energy operation condition to another absorbed one.展开更多
The accurate prediction of photovoltaic(PV)power generation is significant to ensure the economic and safe operation of power systems.To this end,the paper establishes a new digital twin(DT)empowered PV power predicti...The accurate prediction of photovoltaic(PV)power generation is significant to ensure the economic and safe operation of power systems.To this end,the paper establishes a new digital twin(DT)empowered PV power prediction framework that is capable of ensuring reliable data transmission and employing the DT to achieve high accuracy of power prediction.With this framework,considering potential data contamination in the collected PV data,a generative adversarial network is employed to restore the historical dataset,which offers a prerequisite to ensure accurate mapping from the physical space to the digital space.Further,a new DT-empowered PV power prediction method is proposed.Therein,we model a DT that encompasses a digital physical model for reflecting the physical operation mechanism and a neural network model(i.e.,a parallel network of convolution and bidirectional long short-term memory model)for capturing the hidden spatiotemporal features.The proposed method enables the use of the DT to take advantages of the digital physical model and the neural network model,resulting in enhanced prediction accuracy.Finally,a real dataset is conducted to assess the effectiveness of the proposed method.展开更多
Congenital heart disease(CHD)is one of the most common causes of neonatal mortality.The worldwide morbidity of CHD is 9.410%o,while the proportion of CHD patients who are reported to carry mutations in coding regions ...Congenital heart disease(CHD)is one of the most common causes of neonatal mortality.The worldwide morbidity of CHD is 9.410%o,while the proportion of CHD patients who are reported to carry mutations in coding regions is<50%.Enhancers play an important role in the spatio-temporal expression of target genes,and a lot of related variations are associated with CHD.There are conserved and nonconserved enhancers.展开更多
基金supported by VILLUM FONDEN under the VILLUM Investigator Grant(No.25920):Center for Research on Microgrids(CROM)www.crom.et.aau.dk。
文摘The emerging novel energy infrastructures,such as energy communities,smart building-based microgrids,electric vehicles enabled mobile energy storage units raise the requirements for a more interconnective and interoperable energy system.It leads to a transition from simple and isolated microgrids to relatively large-scale and complex interconnected microgrid systems named multi-microgrid clusters.In order to efficiently,optimally,and flexibly control multi-microgrid clusters,cross-disciplinary technologies such as power electronics,control theory,optimization algorithms,information and communication technologies,cyber-physical,and big-data analysis are needed.This paper introduces an overview of the relevant aspects for multi-microgrids,including the out-standing features,architectures,typical applications,existing control mechanisms,as well as the challenges.
文摘Syncope belongs to the transient loss of consciousness(TLOC), characterized by a rapid onset, short duration, and spontaneous complete recovery. It is common in children and adolescents, accounting for 1% to 2% of emergency department visits.Recurrent syncope can seriously affect children's physical and mental health, learning ability and quality of life and sometimes cardiac syncope even poses a risk of sudden death. The present guideline for the diagnosis and treatment of syncope in children and adolescents was developed for guiding a better clinical management of pediatric syncope. Based on the globally recent development and the evidence-based data in China, 2018 Chinese Pediatric Cardiology Society(CPCS) guideline for diagnosis and treatment of syncope in children and adolescents was jointly prepared by the Pediatric Cardiology Society, Chinese Pediatric Society, Chinese Medical Association(CMA)/Committee on Pediatric Syncope, Pediatricians Branch, Chinese Medical Doctor Association(CMDA)/Committee on Pediatric Cardiology, Chinese College of Cardiovascular Physicians, Chinese Medical Doctor Association(CMDA)/Pediatric Cardiology Society, Beijing Pediatric Society, Beijing Medical Association(BMA). The present guideline includes the underlying diseases of syncope in children and adolescents, the diagnostic procedures, methodology and clinical significance of standing test and headup tilt test, the clinical diagnosis vasovagal syncope, postural orthostatic tachycardia syndrome, orthostatic hypotension and orthostatic hypertension, and the treatment of syncope as well as follow-up.
基金supported by the National Natural Science Foundation of China under Project U22B20100in part by State Key Laboratory of Power System Operation and Control(SKLD24 KM14)State-funded Postdoctoral Researcher Program(GZC20231212)。
文摘This paper proposes a fast coordinated power control method based on two augmented channels(AC)in battery energy storage system(BESS)to improve inertial and voltage support capability,i.e.,a frequency-reactive power channel(FRPC)and a voltage-real power channel(VRPC).For frequency control in the power distribution system with high resistance/inductance ratio,the coupling mechanism between rate of change of frequency(RoCoF)and required reactive power(RRP)of grids is analyzed,indicating RoCoF is proportional to RRP.Thus,RoCoF is utilized in FRPC to generate reactive power for complementary inertial emulating control.Meanwhile,for voltage control,coupling characteristics between rate of change of voltage(RoCoV)and demanding real power(DRP)of grids is also studied,revealing RoCoV is proportional to DRP.Therefore,it can be adopted in VRPC to generate real power for complementary voltage control.Then,grid-voltage-modulated direct power control is selected as the inner power control loop to track power references with faster dynamic performance compared with traditional vector-oriented control.Finally,simulations and hardware-in-loop experiments validate improvement in performance of grid frequency and voltage control based on the proposed method.
基金supported by National Key Research and Development Program of China(No.2017YFF0108800)National Natural Science Foundation of China(Nos.61773109,6143304)Major Program of National Natural Foundation of China(No.61573094).
文摘An exponential-function-based droop control strategy for the distributed energy resources(DERs)is proposed to reduce the reactive power-sharing deviation,limit the minimum value of frequency/voltage,whilst improving the utilization rate of renewable energy.Both DERs and loads are interconnected to achieve a power exchange by converters,where the power management system should accurately share the active/reactive power demand.However,the proportional reactive power sharing often deteriorates due to its dependence on the line impedances.Thus,an exponential-function-based droop control is proposed to(1)prevent voltage and frequency from falling to the lower restraint,(2)achieve accurate reactive power sharing,(3)eliminate communication and improve the usage ratio of renewable energy.Furthermore,its stability is analyzed,and the application in islanded AC/DC hybrid microgrids is investigated to achieve the bidirectional power flow.The simulation and experimental results show that the reactive power sharing deviation can be reduced,and the utilization rate of renewable energy is improved by using the proposed method.Moreover,the simulation results illustrate that the system can maintain stable operation when the microgrid is switched from one supplied energy operation condition to another absorbed one.
基金supported by European Horizon 2020 Marie Sklodowska-Curie Actions(No.101023244)。
文摘The accurate prediction of photovoltaic(PV)power generation is significant to ensure the economic and safe operation of power systems.To this end,the paper establishes a new digital twin(DT)empowered PV power prediction framework that is capable of ensuring reliable data transmission and employing the DT to achieve high accuracy of power prediction.With this framework,considering potential data contamination in the collected PV data,a generative adversarial network is employed to restore the historical dataset,which offers a prerequisite to ensure accurate mapping from the physical space to the digital space.Further,a new DT-empowered PV power prediction method is proposed.Therein,we model a DT that encompasses a digital physical model for reflecting the physical operation mechanism and a neural network model(i.e.,a parallel network of convolution and bidirectional long short-term memory model)for capturing the hidden spatiotemporal features.The proposed method enables the use of the DT to take advantages of the digital physical model and the neural network model,resulting in enhanced prediction accuracy.Finally,a real dataset is conducted to assess the effectiveness of the proposed method.
基金This work was supported by The Natural Science Foundation of Shanghai(China)(No.21ZR1410100)The National Natural Science Foundation of China(No.81873481,81771632,81470442,81741081 and 81170147)+2 种基金The National Key Research and Development Program of China(No.2016YFC1000500)National Basic Research Program of China(973 Program)(No.2013CB945401)The Shanghai Key Laboratory of Birth Defects(China)(No.13DZ2260600).
文摘Congenital heart disease(CHD)is one of the most common causes of neonatal mortality.The worldwide morbidity of CHD is 9.410%o,while the proportion of CHD patients who are reported to carry mutations in coding regions is<50%.Enhancers play an important role in the spatio-temporal expression of target genes,and a lot of related variations are associated with CHD.There are conserved and nonconserved enhancers.
