Continuous power supply of urban power networks(UPNs)is quite essential for the public security of a city because the UPN acts as the basis for other infrastructure networks.In recent years,UPN is threatened by extrem...Continuous power supply of urban power networks(UPNs)is quite essential for the public security of a city because the UPN acts as the basis for other infrastructure networks.In recent years,UPN is threatened by extreme weather events.An accurate modeling of load loss risk under extreme weather is quite essential for the preventive action of UPN.Con-sidering the forecast intensity of a typhoon disaster,this paper proposes analytical modeling of disaster-induced load loss for preventive allocation of mobile power sources(MPSs)in UPNs.First,based on the topological structure and fragility model of overhead lines and substations,we establish an analytical load loss model of multi-voltage-level UPN to quantify the spatial dis-tribution of disaster-induced load loss at the substation level.Second,according to the projected load loss distribution,a preventive allocation method of MPS is proposed,which makes the best use of MPS and dispatches the limited power supply to most vulnerable areas in the UPN.Finally,the proposed meth-od is validated by the case study of a practical UPN in China.展开更多
Outage recovery is important for reducing the economic cost and improving the reliability of a distribution system(DS)in extreme weather and with equipment faults.Previous studies have separately considered network re...Outage recovery is important for reducing the economic cost and improving the reliability of a distribution system(DS)in extreme weather and with equipment faults.Previous studies have separately considered network reconfigu-ration(NR)and dispatching mobile power sources(MPS)to restore the outage load.However,NR cannot deal with the scenario of an electrical island,while dispatching MPS results in a long power outage.In this paper,a resilient outage recovery method based on co-optimizing MPS and NR is proposed,where the DS and traffic network(TN)are considered simultaneously.In the DS,the switch action cost and power losses are minimized,and the access points of MPSs are changed by carrying out the NR process.In the TN,an MPS dispatching model with the objective of mini-mizing power outage time,routing and power generation cost is developed to optimize the MPSs’schedule.A solu-tion algorithm based on iteration and relaxation methods is proposed to simplify the solving process and obtain the optimal recovery strategy.Finally,numerical case studies on the IEEE 33 and 119-bus systems validate the proposed resilient outage recovery method.It is shown that the access point of MPS can be changed by NR to decrease the power outage time and dispatching cost of MPS.The results also show that the system operation cost can be reduced by considering power losses in the objective function.展开更多
New research developments suggest that nuclear reactors using fusion may enter the market sooner than imagined even for mobile applications, like merchant ship propulsion and remote power generation. This article aims...New research developments suggest that nuclear reactors using fusion may enter the market sooner than imagined even for mobile applications, like merchant ship propulsion and remote power generation. This article aims at pointing such developments and how they could affect nuclear fusion. The method is enumerating the main nuclear reactors concepts, identifying new technological or theoretical developments useful to nuclear field, and analysing how new recombination could affect feasibility of nuclear fusion. New technologies or experimental results do not always work the way people imagine, being better or worse for intended effects or even bringing completely unforeseen effects. Results point the following designs could be successful, in descending order of potential: aneutronic nuclear reactions using lattice confinement, aneutronic nuclear reactions using inertial along magnetic confinement, hybrid fission-lattice confinement fusion, and fission reactions.展开更多
A new mobile communications network architecture is proposed to solve four existing bottlenecks that restrict the rapid development of mobile communications,as well as to meet the development demands of future broadba...A new mobile communications network architecture is proposed to solve four existing bottlenecks that restrict the rapid development of mobile communications,as well as to meet the development demands of future broadband mobile communications. The architecture introduces the Information Lamp (IL),a novel device carrying out transceiver function,as the access point,besides providing light. It fulfills information interaction between the access points and radio access network through the power line (or fiber). The new system,supported by core technologies such as multi-antenna based distributed space-time signal processing and distributed radio resource management,integrates the wired and wireless networks to provide high-speed and high-quality mobile communication services.展开更多
Mobile power meters allow for cyclists to monitor power output (PO) during training and competition. The Garrnin Vector power meter (VPM) measures PO at the pedal compared to the crank and has been tested in only ...Mobile power meters allow for cyclists to monitor power output (PO) during training and competition. The Garrnin Vector power meter (VPM) measures PO at the pedal compared to the crank and has been tested in only a few limited studies. The purpose of this study was to determine the validity and reproducibility of the VPM by comparing it to the SRM. The VPM validity was tested by (1) a submaximal incremental test, (2) submaximal constant power test, (3) sprint test, and (4) a field test. The reliability of the VPM was tested by repeating the laboratory tests 10 times over a 6 week span. Significant differences (P = 0.046) were found between the mean POSRM (178 ± 1.8 W) and POVPM (163.5 ± 14.7 W) for the submaximal constant-power test. No significant differences were found between the POMAX SRM and the POMAx VPM. The reproducibility of the VPM was lower than the SRM (CV = 8.52 ±4.0 vs 3.48 ± 1.9, 10.66% vs 5.50%, and 67.7% vs 55.3% for the submaximal incremental test, submaximal constant-power test, and field test respectively). The POVPM appears to underestimate the POSRM and is less valid and reliable across various cycling efforts.展开更多
L-shaped plates have become an important focuses in structural vibration research. To determine their vibration characteristics, this paper applied a mobility power flow method. Firstly, the L-shaped plate was divided...L-shaped plates have become an important focuses in structural vibration research. To determine their vibration characteristics, this paper applied a mobility power flow method. Firstly, the L-shaped plate was divided into two substructures to simplify analysis. The coupled bending moment was then deduced by applying a continuous vibration property on the common edge. Next, the response on any point of the plate and the input and transmitted power flow formulas were calculated. Numerical simulations showed the distribution of the coupled bending moment and the response of the whole structure. The validity of this method was verified by the SEA approach.展开更多
The vibrational power flow in the beam-plate assemblies and then with the isolators is investigated using analytical ' power flow' approach based on the some concepts of mechanical mo- bility and structural dy...The vibrational power flow in the beam-plate assemblies and then with the isolators is investigated using analytical ' power flow' approach based on the some concepts of mechanical mo- bility and structural dynamics. Theoretical expressions of the power flow in the structures are given and examined. The numerical results of the expressions are good agreements with the measuring re- sults obtained by the technique of vibration intensity. On the basis of these results, possible ways of reducing the vibrational power flow in the structures are suggested .展开更多
In this paper, virtual instnnnent technology is applied in the development of an electric parameter measta'ement system for mobile power stations. Virtual inset technology is used to lmasure and analyze electric para...In this paper, virtual instnnnent technology is applied in the development of an electric parameter measta'ement system for mobile power stations. Virtual inset technology is used to lmasure and analyze electric parameters of mobile power stations. The whole measurement system is mmpmed of computer, data acquisition card and LabView virtual instnnnent platform. It can be used to monitor, record, and analyze electric parameters of sinusoidal alternating ciroait These parameters include voltage, effective value of ctaxent, phase differences, power, and etc. Experimental results show that this virtual measuring device satisfy the requirement of mobile power station montoring anti dynamic property analysis. Hardware and software design of the system will be discussed in detail.展开更多
A mobility matrix modeling strategy based on axial force solution for a weakly coupled parallel multi-dimentional(multi-DIM)isolator is proposed.Mobility power flow and transmissibility through the isolator are derive...A mobility matrix modeling strategy based on axial force solution for a weakly coupled parallel multi-dimentional(multi-DIM)isolator is proposed.Mobility power flow and transmissibility through the isolator are derived from the mobility matrix.Comparison between simulation and experimental results shows the correctness of the proposed modeling strategy.展开更多
The paper investigates the zero temperature coefficient(ZTC) point of power MOSFET,based on the output characteristic of power MOSFET,the temperature coefficient of threshold voltage and the carrier mobility.It is f...The paper investigates the zero temperature coefficient(ZTC) point of power MOSFET,based on the output characteristic of power MOSFET,the temperature coefficient of threshold voltage and the carrier mobility.It is found that the gate voltage has a big effect on the ZTC point.The result indicates that there are three types of temperature coefficient under different gate voltage.When the gate voltage is near the threshold voltage,both the linear region and saturation region shows a large positive temperature coefficient.With the increase of gate voltage,the temperature coefficient of the linear region changes from positive to negative,when the saturation region still remains positive,giving rise to the ZTC point.When the gate voltage is high enough,the negative temperature coefficient is present on both the linear and saturation region,resulting in no ZTC point.According to the experimental result,the change of ZTC point as a function of temperature is larger when the gate voltage is higher.The carrier mobility is also discussed,displaying a positive temperature coefficient at low gate voltage due to the free charge screen effect.展开更多
基金supported by National Natural Science Foundation of China(No.52307094).
文摘Continuous power supply of urban power networks(UPNs)is quite essential for the public security of a city because the UPN acts as the basis for other infrastructure networks.In recent years,UPN is threatened by extreme weather events.An accurate modeling of load loss risk under extreme weather is quite essential for the preventive action of UPN.Con-sidering the forecast intensity of a typhoon disaster,this paper proposes analytical modeling of disaster-induced load loss for preventive allocation of mobile power sources(MPSs)in UPNs.First,based on the topological structure and fragility model of overhead lines and substations,we establish an analytical load loss model of multi-voltage-level UPN to quantify the spatial dis-tribution of disaster-induced load loss at the substation level.Second,according to the projected load loss distribution,a preventive allocation method of MPS is proposed,which makes the best use of MPS and dispatches the limited power supply to most vulnerable areas in the UPN.Finally,the proposed meth-od is validated by the case study of a practical UPN in China.
基金National Key R&D Program of China (2020YFF0305800)Science and Technology Project of SGCC (520201210025).
文摘Outage recovery is important for reducing the economic cost and improving the reliability of a distribution system(DS)in extreme weather and with equipment faults.Previous studies have separately considered network reconfigu-ration(NR)and dispatching mobile power sources(MPS)to restore the outage load.However,NR cannot deal with the scenario of an electrical island,while dispatching MPS results in a long power outage.In this paper,a resilient outage recovery method based on co-optimizing MPS and NR is proposed,where the DS and traffic network(TN)are considered simultaneously.In the DS,the switch action cost and power losses are minimized,and the access points of MPSs are changed by carrying out the NR process.In the TN,an MPS dispatching model with the objective of mini-mizing power outage time,routing and power generation cost is developed to optimize the MPSs’schedule.A solu-tion algorithm based on iteration and relaxation methods is proposed to simplify the solving process and obtain the optimal recovery strategy.Finally,numerical case studies on the IEEE 33 and 119-bus systems validate the proposed resilient outage recovery method.It is shown that the access point of MPS can be changed by NR to decrease the power outage time and dispatching cost of MPS.The results also show that the system operation cost can be reduced by considering power losses in the objective function.
文摘New research developments suggest that nuclear reactors using fusion may enter the market sooner than imagined even for mobile applications, like merchant ship propulsion and remote power generation. This article aims at pointing such developments and how they could affect nuclear fusion. The method is enumerating the main nuclear reactors concepts, identifying new technological or theoretical developments useful to nuclear field, and analysing how new recombination could affect feasibility of nuclear fusion. New technologies or experimental results do not always work the way people imagine, being better or worse for intended effects or even bringing completely unforeseen effects. Results point the following designs could be successful, in descending order of potential: aneutronic nuclear reactions using lattice confinement, aneutronic nuclear reactions using inertial along magnetic confinement, hybrid fission-lattice confinement fusion, and fission reactions.
基金the National Natural Science Foundation of China under Grants 60572090, 60472045 and 60496313, Ph.D Programs Foundation of Ministry of Education of China under Grant 20050614009.
文摘A new mobile communications network architecture is proposed to solve four existing bottlenecks that restrict the rapid development of mobile communications,as well as to meet the development demands of future broadband mobile communications. The architecture introduces the Information Lamp (IL),a novel device carrying out transceiver function,as the access point,besides providing light. It fulfills information interaction between the access points and radio access network through the power line (or fiber). The new system,supported by core technologies such as multi-antenna based distributed space-time signal processing and distributed radio resource management,integrates the wired and wireless networks to provide high-speed and high-quality mobile communication services.
文摘Mobile power meters allow for cyclists to monitor power output (PO) during training and competition. The Garrnin Vector power meter (VPM) measures PO at the pedal compared to the crank and has been tested in only a few limited studies. The purpose of this study was to determine the validity and reproducibility of the VPM by comparing it to the SRM. The VPM validity was tested by (1) a submaximal incremental test, (2) submaximal constant power test, (3) sprint test, and (4) a field test. The reliability of the VPM was tested by repeating the laboratory tests 10 times over a 6 week span. Significant differences (P = 0.046) were found between the mean POSRM (178 ± 1.8 W) and POVPM (163.5 ± 14.7 W) for the submaximal constant-power test. No significant differences were found between the POMAX SRM and the POMAx VPM. The reproducibility of the VPM was lower than the SRM (CV = 8.52 ±4.0 vs 3.48 ± 1.9, 10.66% vs 5.50%, and 67.7% vs 55.3% for the submaximal incremental test, submaximal constant-power test, and field test respectively). The POVPM appears to underestimate the POSRM and is less valid and reliable across various cycling efforts.
基金Supported by the National Natural Science Foundation under Grant No. 50675177.
文摘L-shaped plates have become an important focuses in structural vibration research. To determine their vibration characteristics, this paper applied a mobility power flow method. Firstly, the L-shaped plate was divided into two substructures to simplify analysis. The coupled bending moment was then deduced by applying a continuous vibration property on the common edge. Next, the response on any point of the plate and the input and transmitted power flow formulas were calculated. Numerical simulations showed the distribution of the coupled bending moment and the response of the whole structure. The validity of this method was verified by the SEA approach.
文摘The vibrational power flow in the beam-plate assemblies and then with the isolators is investigated using analytical ' power flow' approach based on the some concepts of mechanical mo- bility and structural dynamics. Theoretical expressions of the power flow in the structures are given and examined. The numerical results of the expressions are good agreements with the measuring re- sults obtained by the technique of vibration intensity. On the basis of these results, possible ways of reducing the vibrational power flow in the structures are suggested .
文摘In this paper, virtual instnnnent technology is applied in the development of an electric parameter measta'ement system for mobile power stations. Virtual inset technology is used to lmasure and analyze electric parameters of mobile power stations. The whole measurement system is mmpmed of computer, data acquisition card and LabView virtual instnnnent platform. It can be used to monitor, record, and analyze electric parameters of sinusoidal alternating ciroait These parameters include voltage, effective value of ctaxent, phase differences, power, and etc. Experimental results show that this virtual measuring device satisfy the requirement of mobile power station montoring anti dynamic property analysis. Hardware and software design of the system will be discussed in detail.
基金Supported by the National Natural Science Foundation of China(No.51505124)the Scientific Research Initiation Foundation of North China University of Science and Technology(No.28405699).
文摘A mobility matrix modeling strategy based on axial force solution for a weakly coupled parallel multi-dimentional(multi-DIM)isolator is proposed.Mobility power flow and transmissibility through the isolator are derived from the mobility matrix.Comparison between simulation and experimental results shows the correctness of the proposed modeling strategy.
文摘The paper investigates the zero temperature coefficient(ZTC) point of power MOSFET,based on the output characteristic of power MOSFET,the temperature coefficient of threshold voltage and the carrier mobility.It is found that the gate voltage has a big effect on the ZTC point.The result indicates that there are three types of temperature coefficient under different gate voltage.When the gate voltage is near the threshold voltage,both the linear region and saturation region shows a large positive temperature coefficient.With the increase of gate voltage,the temperature coefficient of the linear region changes from positive to negative,when the saturation region still remains positive,giving rise to the ZTC point.When the gate voltage is high enough,the negative temperature coefficient is present on both the linear and saturation region,resulting in no ZTC point.According to the experimental result,the change of ZTC point as a function of temperature is larger when the gate voltage is higher.The carrier mobility is also discussed,displaying a positive temperature coefficient at low gate voltage due to the free charge screen effect.