基于风速功率关系带的时间序列法预测研究

在运用时间序列法预测风速及风电功率的基础上,采用分层统计法对16台风电机组的风速功率数据进行统计分析,得出基于实测数据的风速功率关系带,用于提取有效历史功率点,达到提高风电功率预测精度的目的．运用MATLAB软件编程实现预测,并选取合适的误差衡量指标进行误差分析．     

Thermodynamic analysis of simplified dual-pressure ammonia-water absorption power cycle

A simplified dual-pressure ammonia-water absorption power cycle (DPAPC-a) using low grade energy resources is presented and analyzed. This cycle uses turbine exhaust heat to distill the basic solution for desorption. The structure of the cycle is simple which comprises evaporator, turbine, regenerator (desorber), absorber, pump and throttle valves for both diluted solution and vapor. And it is of high efficiency, because the working medium has large temperature difference in evaporation and small temperature difference in absorptive condensation, which can match the sensible exothermal heat resource and the cooling water simultaneously. Orthogonal calculation was made to investigate the influence of the working concentration, the basic concentration and the circulation multiple on the cycle performance, with 85–110 °C heat resource and 20–32°C cooling water. An optimum scheme was given in the condition of 110 °C sensitive heat resource and 20 °C cooling water, with the working concentration of 0.6, basic concentration of 0.385, and circulation multiple of 5. The thermal efficiency and the power recovery efficiency are 8.06 % and 6.66%, respectively. The power recovery efficiency of the DPAPC-a is 28.8% higher than that of the steam Rankine cycle (SRC) and 12.7% higher than that of ORC (R134a) under the optimized situation.     

Scattering loss in optical waveguide with trapezoidal cross section

To get the scattering loss of the trapezoidal core waveguide, a new analysis model is presented based on the perturbation equivalent method and modified effective-index method. Firstly, the trapezoidal core waveguide is successfully equivalent to the rectangular one with both restricting the same optical field energy by adopting the perturbation method. Then, the equivalent rectangular core waveguide is decomposed into two slab waveguides by employing the modified effective-index method. The trapezoidal core waveguide scattering theory model is established based on the slab waveguide scattering theory. With the sidewalls surface roughness in the range from 0 to 100 nm in the single model trapezodial core waveguide, optical simulation shows excellent agreement with the results from the scattering loss model presented. The relationship between the dimension and side-wall roughness with the scattering loss can be determined in the trapezoidal core waveguide by the scattering loss model.     

采用RM算法的WiNCS功率控制建模与仿真

针对无线网络控制系统中节点的功率控制问题,提出了一种基于单调速率(RM)调度算法的功率单调控制策略(PMS)。借助Matlab/TrueTime工具箱构建系统的仿真模型,并与M-D策略进行比较。结果表明:PMS策略具有明显优势,可以显著提高系统的稳定性和功率利用率。     

不同比功率分区下轻型车排放特征分析

为了反映轻型车排放随发动机输出功率的变化关系,搭建轻型车车载排放测试试验平台,通过实际道路试验获取质量排放数据与对应的行驶状态数据;为了便于与交通仿真模型融合,将比功率分成10区,分析了3种污染物质量排放率随比功率分区的变化关系,并计算得到了10个分区内3种排放污染物的质量排放率。结论表明,轻型车3种污染物质量排放率与比功率具有很高的相关性;bin1～bin3对应着轻型车制动减速的情况,排放速率最慢;bin6～bin10对应着轻型车车速高以及急加速度情形,排放速率最高;研究得到的不同比功率分区下的质量排放率可以作为与交通仿真模型结合来量化区域排放的依据。     

基于瞬时效率的功率分流式混合动力汽车最佳分离因子的确定

介绍一种基于系统瞬时效率优化的功率分流式混合动力汽车最佳分离因子的三重迭代确定方法。得到最佳分离因子与车速和需求功率的函数关系,并基于最佳分离因子开发出功率分流式混合动力汽车的瞬时最优控制算法。与基于发动机最优曲线控制算法相比,基于最佳分离因子的系统瞬时最优控制算法经济性有明显的提高。     

基于改进电导增量法的光伏发电系统MPPT控制研究

提出了一种改进的电导增量法,该方法在远离最大功率点时采用在线固定参数法,而在最大功率点处采用电导增量法.通过仿真试验证明,该方法可以根据外部环境的变化,快速、准确地跟踪到最大功率点,并能有效地减少最大功率点处的功率振荡现象.     

基于最大功率点跟踪策略的LED太阳能路灯照明系统

在太阳能电池电路模型的基础上,针对传统太阳能路灯系统中防电流倒灌二极管使系统输出功率下降的问题,提出了一种数模混合型最大功率点跟踪(MPPT)策略,并根据该策略和固态光源LED驱动电路的要求,设计了一个高亮度LED太阳能路灯照明系统。实验结果表明,该系统工作稳定可靠,性能优良,可提高太阳能利用率20%左右,具有较高的实用价值。     

船闸通航对水电站发电功率的动态影响浅析

1盐河水电站概况 盐河闸位于淮安市淮阴区王营镇淮闸村,系盐河的控制工程,于1959年4月竣工,共15孔,单孔净宽3m,闸总宽61．98m,闸底高程6-3m,设计流量230m^3／s,校核流量276m^3／s。为了合理利用盐河上下游丰富的水能资源,1973年5月盐河闸13#-15#孔改建为闸孔电站,即盐河水力发电站,安装有3台单机容量500kW的小水电机组,并网发电后近年来年发电量可达580万kwh。