共查询到20条相似文献，搜索用时 31 毫秒
1.
The Kalman filter algorithm can be used to estimate the state of charge (SOC) of power batteries, however, it easily causes divergence due to uncertain of system noise and its estimation performance is affected by model. An adaptive Kalman filter algorithm is adopted to dynamically estimate SOC of lithium iron phosphate batteries for application in electric vehicles. At first, an equivalent circuit model, appropriate for SOC estimation is built after studying battery models. Then some charging and discharging experiments are carried out for parameter identification and the results are verified. At last, the adaptive Kalman filter algorithm is used on this model for on-line SOC estimation under unknown interfering noise. Simulation results show that adaptive Kalman filter method can correct SOC estimation error caused by tiny model error online, and the estimate accuracy is higher than Kalman filter method. Adaptive Kalman filter algorithm can also correct the initial error. Full-cycle test in electric vehicles proves that the algorithm is appropriate for SOC estimation of lithium iron phosphate battery. 相似文献
2.
RAN Zhen-ya~ 《保鲜与加工》2004,(6):25-29
The powertrain of a new type of zero emission electric vehicle is researched, which powered primarily by air-breathing proton exchange membrane (PEM )fuel cells with gaseous hydrogen as fuel,and with Lead-acid battery as assistant power.The fuel cell system provides power for the vehicle while the vehicle travel at a cruising speed,and the exceed power will charge for battery.The fuel cell and the battery system will together provide power to the vehicle during periods of peak power demand such as vehicle acceleration or traveling at a high constant speed.At the same time, the powertrain parameter of this fuel cell vehicle are matched reasonably.At last, the dynamic of an electric vehicle is simulated, and the result shows that the dynamic performance perfectly meets the need of the design target. 相似文献
3.
光储微电网混合储能系统的控制策略及开关优化 总被引：1，自引：0，他引：1
传统光储微电网混合储能系统控制策略将蓄电池视为容量无限大的理想元件,而实际上蓄电池容量有限,当蓄电池剩余电量达到阈值无法正常工作时传统控制策略将不适用。在二阶低通滤波法的基础上提出一种光储微电网混合储能系统的新型控制策略,同时考虑超级电容与蓄电池的剩余电量,根据储能元件的荷电状态调整储能元件输出电流参考值,维持储能元件剩余电量,但在极端天气情况下,仍需与储能元件保护开关相配合。由于采用传统储能元件保护开关的储能系统需独立的充放电电路,存在成本较高、充放电不连续等问题,因此,对储能元件的保护开关进行了改进,利用开关与二极管并联使其具有4种工作状态,在储能元件剩余电量达到阈值时,可自动恢复电量,降低了成本,提高了并网输出电能质量。最后结合新型控制策略与改进的保护开关,提出整体的混合储能系统控制方案,并用Matlab/Simulink对其进行仿真验证,结果证明了所提方法的正确性与可行性。 相似文献
4.
In order to investigate the effective seismic capacity design measures of shear wall and to realize expected failure modes under strong earthquake,the existing problems in current seismic capacity design measures are pointed out through theoretical analysis.The effectiveness of the measures of Chinese seismic design code is verified by fine finite element dynamic time-history analysis of examples.Improving measures are then put forward and are verified through example analysis.It is shown the bending ductile demand of bottom section of shear wall increases too much based on moment capacity design measures of Chinese seismic design code 2001 in the rigid foundation assumption under rare earthquake action,and its bearing capacity for vertical axis force loses;the shear capacity design measures of current seismic design code would lead to shear failure in the stores above the bottom ductility strengthening area.Some improved bending and shear seismic capacity design measures of shear wall are proposed and are verified to be effective. 相似文献
5.
Powertrain parameter design for the electric vehicle with taking the energy consumption of air conditioner into consideration 
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下载免费PDF全文 On the basis of considering the influence of air conditioner on vehicle performance,the parameter determination of the power train composed of a battery,a traction motor and a two-speed transmission of an electric car is carried out. To ensure the economy of operation,a shifting strategy with a principle which emphasizes the high work efficiency of the power train is drawn up and the gear ratios are corrected aiming at the least energy cost over the drive cycle. The simulation results indicate that the designed parameters meet the requirements moderately and the driving range is extended by 5.28% when the air conditioner is turned off and 4.29% when turned on,compared with the initial results through the correction of the gear ratios. 相似文献
6.
Since the wind turbines are installed on the flexible support tower, the drive train of the wind turbines runs under severe work conditions with varying wind directions and loads. So its failure rate is high and it is the bottle neck of the wind power development. This work presents a study which takes the coupling effect of oscillating of tower barrel and the twisting vibration of driven train into account. Using the lumped parameter method, a coupled dynamic model for the megawatt wind turbine drive train is built by considering the flexible tower barrel support effects. Then, the dynamic characteristics of the megawatt wind turbine drive train are analyzed. The Campbell chart is used in this research to analyze the potential resonance points. And the potential resonance frequencies between the cutting in and cutting out rotational speed of the drive train are obtained. Finally, Simpack is used to analyze the dynamic characteristics of drive train and verify the correctness of the proposed method. 相似文献
7.
《保鲜与加工》2003,(11):6
This paper briefly introduces the structure and main function of a mild hybrid system based on ISA. The components of the whole powertrain system include ISA,engine and battery. Transmission is choosed according to its typical configuration and functions. In addition,the specific parameters of power and torque of ISA,engine power,the number and capacity of battery,the gear ratio of gearbox are determined according to the required performance and fuel economy. In order to achieve the design target, the Genichi Taguchi method is used to optimize the gear ratio. At the same tine, the simulation of ISA mild hybrid vehicle is carried out and compared with conventional vehicle by using the ADVISOR software. 相似文献
8.
The dynamic behavior of railway bridges (dynamic deflection and acceleration) is one of the running safety control indices for high speed trains. Therefore, the dynamic behavior of railway bridges is studied based on the concept of the dynamic signatures of the train and the bridge. By simplifying the train excitation as a series of moving concentrated forces, the mathematical expressions of the dynamic signatures of the train are obtained through theoretical derivations, and then a method is presented for calculating the resonance speed of trains and the maximum vertical acceleration of the bridge. With this method, the dynamic responses of the simple supported bridge can be calculated quickly. The feasibility of this method is validated through some examples, in which the resonance mechanism of train bridge system and the influencing factors are investigated. In addition, the effect of high frequency components to the bridge acceleration is also analyzed. 相似文献
9.
On the basis of a planetary transmission, a novel hydrodynamic speed controlled transmission system for wind turbines with large capacity is presented. The new drive train consists of wind rotors, planet accelerators, hydro-mechanical and synchronous generators. The dynamic mathematical model of the drive train is established. The digital simulation of speed regulation characteristics for hydrodynamic speed controlled system is studied by using Matlab/Simulink. The simulation results show that continuously variable transmission and fixed speed control can be achieved, and the drive train works well in stability and dynamic performances. They can increase the power yield from the wind, smooth the electric power output, and alleviate the load peak in the new drive train . 相似文献
10.
For the requirement of building up the battery management system (BMS) of hybrid vehicles(HEVs), the real time measurement and estimation of charge (SOC) of the Ni MH batteries are investigated, because the popular SOC definition is unsuitable under the condition of variable current discharge. The origin of this kind unsuitability are analyzed ,and the characteristics and existing problems of different kinds of SOC measuring methods are compared. On the basis of mentioned above, some corrections are given to the popular SOC definition, and the new conception of SOC is proposed. The corrected definition of SOC is suitable for the real time SOC estimation under the variable current condition of the batteries used in HEVs. Based on the corrected SOC definition, the computational model of the new SOC is built and simulated. Satisfactory result has been obtained from comparisons of the simulating results, which shows that the theoretical model provides a basis for optimizing the adaptation of power system to the hybrid vehicles (HEVs). 相似文献
11.
Control Strategy and Simulation Study on NiMH Battery Quick Charging for Regenerative Braking of HEV
Based on the result of NiMH battery performance experiments, changing trend of maximal temperature and difference in temperature of HEV NiMH battery in different SOC and different charging current is analyzed. Considering the working situation of HEV NiMH battery and the theory of battery quick charging, a control strategy for NiMH battery quick charging is described which adapts to HEV regenerative braking system based on Mascc law. By Modeling and simulating the process of NiMH battery quick charging with this strategy, constant voltage charge method and constant current charge method, validates this control strategy. 相似文献
12.
In the era of "post-PC", embedded system is regarded as a new representation. And its characteristics and developing technology are focused. The traits of embedded system, which are low power processor, compact operating system, prolifically peripheral interfaces and form, and its inner modularized framework are parsed. The typical developing pattern of embedded system is put forward,which is called Host-Target pattern . This pattern can make developers have clear design train of thoughts and divide the work, and also make the developing synchronously. And cross-compile and remote debug is the typical developing characteristics of Host-Target pattern. They are both discussed in this article. Finally we prospect the future of embedded system, and the network, system on chip (SOC) and lower cost of embedded systems are regard as its tendency by author. 相似文献
13.
3-D Dynamic Response of Reinforced Embankment and Track System Subjected to Moving Traffic Load 总被引：1，自引：0，他引：1
An analytic method was used to study the dynamic response of track system on reinforced embankment subjected to moving traffic load. Based on Biot's dynamic poro-elastic theory, dynamic analytical model of track system and reinforced embankment was established. The rails were described as an infinitely long Euler beam subjected to moving axle loads and sleepers were represented by continuous mass. Reinforced embankment embedded between track system and poro-elastic subsoil was modeled as a transversely isotropic layer. Subsoil was fully saturated poroelastic medium governed by the Biot's theory. Using the Fourier transform, the governing equations were then solved analytically in the frequency-wave-number domain. The time domain responses were obtained by the inverse Fourier transform computation. The influences of the train velocity, thickness of reinforced layer, load amplitude and reinforcement's ratio on the displacement responses of rails were carefully investigated. Computed results show that the vertical displacement of rails increases with the increase of load speed initially and decreases later. The displacement of rails with reinforced embankment is less than the ones without reinforced embankment. The displacement of rails increases with the increase of load amplitude and decreases with the increase of reinforcement's ratio. 相似文献
14.
A fuzzy multi-objective control strategy is proposed for parallel hybrid electric vehicles (PHEV). By the concept of motor equivalent fuel consumption, the overall vehicle fuel economy and the corresponding emissions can be treated as the optimization objectives. Then a minimum average weighted deviation method is designed to find the Pareto optimal solution with considering the variations of objective preference in different district. The simulation on ADVISOR reveals that, compared with the rule based control strategy (RBCS), with the premise that there is no loss to power performance, the proposed fuzzy multi-objective control strategy (FMCS) not only improves fuel economy and emission level but also maintains battery SOC within its operation range more effectively. 相似文献
15.
微山县农田耕层土壤有机碳空间变异及动态变化分析 总被引：1，自引：0，他引：1
为研究微山县农田耕层土壤有机碳空间变异规律和动态变化情况,基于地统计学和GIS对2009农田土壤耕层有机碳进行空间变异分析,并进行克吕格插值分析土壤有机碳空间分布格局及影响因素,然后与第二次土壤普查数据对比研究了两不同时间断面下土壤有机碳含量的动态变化特征。结果表明：微山县耕层土壤有机碳最佳拟合模型为指数模型,具有较弱的空间自相关性,空间自相关距离为4500 m。从空间分布格局上看,土壤有机碳分布呈明显的块状,有机碳含量中部较高,南部和北部较低。从第二次土壤普查到2009年近30年间,土壤有机碳含量的平均值有明显的增加,由5.345 g/kg上升到8.558 g/kg,增幅60.11%。不同土壤类型下,增幅不同,其中棕壤增幅最大,为187.03%,增幅最小的为砂姜黑土,为41.64%。不同土地利用类型下,水田类型下土壤有机碳增幅最小,为56.84%,旱地类型下,土壤有机碳增幅最大,为87.75%。本研究为该区耕地质量的提高、农田生态系统的碳循环和农业的可持续发展提供可靠依据。 相似文献
16.
Considering that the transmission system of wind turbine works in complex and changing load environment caused by stochastic wind speed,this paper uses sparse least squares support vector machine(SL-SVM) to simulate wind speed of true wind field,and obtains time-varying wind load caused by stochastic wind speed. The lumped-parameter method is used to develop a dynamic model of planetary gear transmission system of wind turbine coupled with bearing. The model includes the varying wind load,time-vary mesh stiffness of gear pair and time-vary stiffness of rolling element bearing. The numerical method is used to simulate the dynamic performance of planetary gear system of Multibrid Technology Wind Turbine with 1.5 MW rated power. The vibration displacement responses of the transmission system are obtained as well as dynamic meshing force each pair of gear and nonlinear bearing forces. The research can provide a foundation for optimizing dynamic performance and reliable design of gear transmission system of wind generator. 相似文献
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18.
Through the analysis of the equivalent resistance method, a limitation of the equivalent capacity method was presented. When the direction of power at the feeder source end was changing, the equivalent capacity method for handling small generations would produce a large power loss calculation error. An improved calculation method, one not based on a single equivalent resistance, was proposed. In this method, one day was divided into several periods (such as 24 h), so that the direction of power at the feeder source end for each period does not vary. The equivalent resistance and energy loss in each period were calculated. The sum of all energy losses provided the daily energy loss total. Numerical examples were used to verify the improved method. 相似文献
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20.
Pang Youxia Li Xiaohong Qin Wenxue 《保鲜与加工》1999,(2):75-80
The paper analyzed the force on the filler sealing in the centrifugal pumps.Through the experiments,the factors affecting the leakage rate were found such as the pressing force,the firction coefficient filler,the oviginal gap,the length of the sealing ring and so on.In the experiments,when the PTFE Ekonol Graphite,self lubricating composite materials were used as the sealing filler of the centrifugal pumps and the dynamic design was made,it showed that the performance of the pumps was obviously better than where the asbestos was.As a result,it may solve the leakage of the pumps and decrease the power loss because of friction. 相似文献