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991.
针对目前太阳能跟踪系统存在的跟踪精度不高,抗干扰能力差的缺点。设计一种以视日运动轨迹跟踪和光电检测跟踪相结合的控制方法对太阳能进行跟踪,并且以DSP为控制器核心芯片的高精度太阳能智能跟踪系统。视日运动轨迹跟踪对太阳进行粗跟踪,再利用光电检测跟踪对太阳进行精确跟踪。实现对太阳的高精度跟踪,并且使系统具有较强的抗干扰和运算能力。 相似文献
992.
对控股股东股利分配行为的监管,是监管部门和控股股东之间的博弈过程。均衡分析发现,监管部门的监管成本C越小、控股股东进行侵占造成的外部损失W(ζ)越大,控股股东进行规范分配的概率越大;控股股东持股比例L越高、对控股股东违规处罚的力度K越大,监管部门监管的概率越小。 相似文献
993.
河南省秸秆生物质资源量测算 总被引:1,自引:0,他引:1
利用2002—2007年河南省统计年鉴中农作物产量数据,定量测算了河南省秸秆生物质资源的实物量、理论可获得量,并探讨了其地理分布格局。研究表明:2002—2007年河南省秸秆实物蕴藏量平均值7 244万t,主要分布于南阳市、商丘市、信阳市、周口市、驻马店市等5个市,地理分布不均匀,可用于生物质资源的理论可获得量平均为1 835万tce;平均能源密度为110.89 tce/km2,较高密度地区主要是漯河市、周口市、许昌市、濮阳市等4个市。 相似文献
994.
995.
Based on a on site wind turbine’s output active power vs. generator speed curve, the shortage of conventional power control strategies of doubly fed wind turbine generation system are analyzed. Considering the generator speed restriction and active power fast track control requirement, the power decoupling control strategy in the rotor side converter and variable pitch control strategy are improved, that is, an output mechanical torque of wind turbine and the generator speed of DFIG are used in the rotor side active power control loop in order to achieve an accurate optimal speed control, as well as a direct active power control method is also adopted in the variable pitch control strategy. Finally, the overall operational performances of DFIG wind turbine generation system using the proposed control strategies are simulated, and also compared with the conventional control strategies. The results show that the improved control strategy is more valid and correct. 相似文献
996.
In order to study the rule of drivers’ pupil changing with luminance under road lighting condition,pupil area of 4 subjects under 13 lighting levels of high pressure sodium(HPS), metal halide(MH) and LED are measured, with reaction time test equipment for road lighting and iView X eye tracking system. The results indicate that the relationship between pupil area and background luminance is negative exponential function, pupil will shrink while luminance is increased, the shrink velocity of pupil will decrease while luminance’s increasing, and pupil area will tends to be constant when luminance reach some level. Under the three lighting sources used in the experiment, pupil area will fluctuate while the background luminance is between 0.7 cd/m2and 1.2 cd/m2. 相似文献
997.
Lighting and air conditioning energy consumption of stadium is very large. That how to use natural lighting and natural ventilation is the key pivot for stadium energy efficiency design. A variety of passive energy efficient measures were used in the Multi functional stadium of Guangdong College of Pharmacy, such as lighting windows with vertical blinds in east and west facades, Openable windows on south and north facades, planting roof and etc. It was found that the above mentioned passive designs could 〖JP2〗increase natural illumination of competition venues, prevent the glare, raise wind speed in audience area, improve comfort level and decrease internal surface temperature of affiliated building and reduce heat radiation. 相似文献
998.
It is studied how to charge the battery of the implanted medical device through the skin according to its bio electrical characteristics.Energy delivery model of volume conduction is created by FEMlab 3.3 (Finite Element Model Lab),using AC voltage as the input.In simulation,the frequency characteristic of the model is tested,and then 4 different shapes of electrodes are designed.Taking cylindrical electrode for example,the shape and layout of electrode are optimized by changing the electrodes’ cross section areas and the distance between the electrodes.According to the simulation results,current transmitting efficiency can reach above 30% under the premise of ensuring human security. 相似文献
999.
Analysis of reasonable wind farm energy storage capacity range 总被引:3,自引:1,他引:2
The wind farm output power fluctuations caused by changing wind speed can be improved by configuring the appropriate storage energy capacity .For the problem that how to select the storage capacity more economical, two indicators for the judgment of the optimization wind power output are mentioned, which is based on a method calculating storage energy capacity. By detailed analysis of the all kinds of factors that can influence the reasonable value of storage capacity, and by using the cost of storage capacity and the smoothing effect of wind farm output as assistant criterion, a reasonable storage capacity range is discussed. 相似文献
1000.
It is important to utilize coal bed methane to achieve the safe, environmental and economic benefits. The authors simulate the processes of multi jet diffusion combustion of low concentration coal bed methane using k ε turbulence model,non premixed combustion model and P1 radiation model. The influences of different geometrical structures and operating parameters on the combustion process are compared with each other. The results show that the distance between the gas nozzles and central axis,the angle of gas deflected from air ,the velocity ratio of air to gas have important impacts on the combustion. When the distance, the deflection angle and the velocity ratio are 30 mm,45 °and 2, respectively. The best combustion result can be achieved. 相似文献