MRD减振控制系统的后备混合储能电源设计与仿真

针对磁流变阻尼器MRD(magnetorheological damper)减振控制系统后备电源采用单一蓄电池供电存在响应时间慢和稳定性差问题,提出锂电池/超级电容的后备混合储能电源。首先进行储能系统供电方式的选择及容量配置,然后设计了锂电池和超级电容分别串联双向DC/DC变换器进行功率分配的混合储能结构,再将负载端电流滤波后的高频分量和低频分量用来实现变换器电压电流闭环控制,最后在Matlab/Simulink中搭建混合储能仿真模型,进行输出响应和脉冲功率扰动仿真,对单一锂电池储能和混合储能电源进行性能比较。结果表明,混合储能电源的输出响应时间可达毫秒级;超级电容能提供80%起始功率,并且在脉冲功率扰动下补偿波动功率,以维持母线端稳定,满足MRD减振控制系统的实际工程需求。     

基于混合型Chopper电路的MMC-UPFC故障渡越方案

当交流系统发生短路时,基于模块化多电平控制器的统一潮流控制器(MMC-UPFC)串、并联侧MMC均会受到故障冲击,存在两侧换流器过流闭锁,MMC-UPFC完全退出运行的风险.对此,以交流系统发生最严重的三相短路故障为例,分析了MMC-UPFC串、并联侧MMC故障特性;在此基础上,借鉴风电场交流故障渡越的Chopper电路,并结合MMC-UPFC不同运行方式对故障特性的影响,提出了基于混合型Chopper电路的MMC-UPFC故障渡越方案.该方案能够在交流系统发生故障后隔离并联侧MMC与串联侧MMC之间的联系,从而抑制串联侧馈入并联侧MMC的故障电流.仿真结果表明在MMC-UPFC的不同运行方式下,所提方案均能避免故障后并联侧MMC闭锁,MMC-UPFC将切换至静止同步补偿器(STATCOM)工作模式,为交流系统提供无功功率支撑.     

关注区可变的实时仿真方法与平台

交直流混合电网的实时仿真既要考虑电力电子设备的开关特性,又要保证适应较大的电网规模,在实际工程中面临诸多困难.给子网络赋予动态可变的关注标志,对关注子网络采用存储压力小的节点消去法,对非关注子网络采用计算量少的线性组合法,从而保证骨架型节点电压法的实用性.在Xilinx公司的Virtex-7 FPGA VC709开发板中,采用无缝的并行化仿真计算程序对接方式和灵活的结构参数查询方法解决了现场可编程逻辑门阵列资源的紧缺问题,设计了一种关注区可变的实时数字仿真平台.以典型的交直流混合电网为例,仿真验证了所提方法的可行性与所研发平台的有效性.     

微电网跟踪调度计划双层双时间尺度实时控制策略

为了提升微电网跟踪调度计划的能力,并降低分布式电源和负荷的功率波动对跟踪效果的影响,提出一种利用由超级电容和电池储能组成的混合储能系统跟踪调度计划的双层双时间尺度实时控制策略。上层基于模型预测控制方法建立日内滚动优化模型,结合分布式电源和负荷的超短期功率预测结果,综合考虑一段时域内的跟踪偏差及混合储能系统的功率和荷电状态对跟踪调度计划进行滚动优化;下层在上层优化结果的基础上,采用基于荷电状态的混合储能系统实时控制策略对超级电容和电池储能的实时功率进行协调分配,进一步降低分布式电源和负荷的实时功率波动对跟踪效果的影响。通过仿真算例对所提控制策略进行验证,结果表明:所提策略不但实现了良好的实时跟踪调度计划的控制效果,而且优化了超级电容和电池储能的荷电状态。     

多子微电网型交直流混合配电系统灵活功率控制与电压抑制策略

为了解决多子微电网型交直流混合配电系统功率分配以及交流子微电网母线电压偏差大的问题,提出一种灵活功率控制与电压抑制策略.首先分别推导了单个交流子微电网频率、直流子微电网电压与公共直流母线电压的关系,然后分析多个交直流子微电网之间的频率与电压关系,并利用此关系对交直流子微电网中储能单元的下垂控制进行改进,实现整个系统的功率互助及分配.另外,对双向AC/DC变换器电流内环控制进行改进,利用扩张状态观测器对扰动电流进行跟踪,并将跟踪得到的扰动电流引入双向AC/DC变换器电流内环中进行补偿消除,以抑制交流子微电网的电压波动.最后,在MATLAB/Simulink仿真平台中建立多子微电网型交直流混合配电系统模型,仿真结果表明所提控制方法可以实现交直流混合配电系统中子微电网间的功率互助,较好地维持交流子微电网母线电压和频率、直流子微电网电压与公共直流母线电压的稳定.     

Processing of yttria partially stabilized zirconia thermal barrier coatings implementing a high-power laser diode

Several studies have been undertaken recently to adapt yttria partially stabilized zirconia (YPSZ) thermal barrier coating (TBC) characteristics during their manufacturing process. Thermal spraying implementing laser irradiation appears to be a possibility for modifying the coating morphology. This study aims to present the results of in situ (i.e., simultaneous treatment) and a posteriori (i.e., post-treatment) laser treatments implementing a high-power laser diode. In both cases, the coatings underwent atmospheric plasma spraying (APS). Laser irradiation was achieved using a 3 kW, average-power laser diode exhibiting an 848 nm wavelength. Experiments were performed to reach two goals. First, laser post-treatments aimed at building a map of the laser-processing parameter effects on the coating microstructure to estimate the laser-processing parameters, which seem to be suited to the change into in situ coating remelting. Second, in situ coating remelting aimed at quantifying the involved phenomena. In that case, the coating was treated layer by layer as it was manufactured. The input energy effect was studied by varying the scanning velocity (i.e., between 35 and 60 m/min), and consequently the irradiation time (i.e., between 1.8 and 3.1 ms, respectively). Experiments showed that coating thermal conductivity was lowered by more than 20% and that coating resistance to isothermal shocks was increased very significantly.     

聚氨酯-聚丙烯酸酯复合乳液的动态力学性能

采用种子乳液聚合法合成了聚氨酯一聚丙烯酸乙（丁）酯[PU／PE（B）A]复合乳液。并研究了不同组成对复合乳液性质、相客性、阻尼性能及拉伸性能的影响。耐水性及稳定性测试表明，随PE（B）A含量的增加，涂膜的耐水性变好，而乳液的稳定性变差。动态力学性能测试（DMS）表明，合成的PU／PE（B）A复合乳液为半相容体系，其相容性随PE（B）A含量的增加而增强。DMS和拉伸试验表明PU／PEA／P（B）A（质量比50／25／25）复合乳液具有优良的阻尼性能、抗拉强度和断裂伸长率，可用作宽温域阻尼涂料。     

Hydrogen sorption sites in the gallium containing hybrid catalysts used for the aromatization of light alkanes

Gallium species which were incorporated initially in the oxide form, were all in the (+3) oxidation state in the hybrid catalyst and exhibited two types of hydrogen chemisorption sites, s_hw and s_hs. The stronger sorption sites shs which predominated at higher gallium dispersion, corresponded probably to the most effective surface configuration for gallium in the aromatization ofn-butane.     

Synthesis of Novel Chelating Adsorbents for Boron Uptake from Aqueous Solutions

Two kinds of novel chelating adsorbents have been synthesized to separate boron from aqueous solutions. One is the boron-specific chelating resin, synthesized by the functionalization of macroporous poly (glycidyl methacrylate-co- trimethylolpropane trimethacrylate), with N-methylglucamine. The other is the organic-inorganic hybrid mesoporous SBA-15 with polyol functional groups, prepared by a two-step post-grafting method. The resin can adsorb boron in almost all pH range, and its maximum uptake capacity reaches 1.15 mmol/g. The present study of the polyol-functionalized SBA-15 shows that the post-grafting is successful and the resulting adsorbent has the uptake capacity of 0.63 mmol/g.     

壳聚糖/磷钙杂化膜的制备与性能研究

将壳聚糖/钙盐复合膜浸泡在磷酸二氢钾溶液中制备了壳聚糖/磷钙杂化膜.用电子扫描电镜观察杂化膜和膜内磷钙微粒的形貌,研究了杂化膜的力学性能、溶胀率、吸光度及热稳定性.结果表明,杂化膜内磷钙晶体为柱状和层状结构,磷钙被包裹在杂化膜内,并与壳聚糖膜形成紧密的连续结构.随着膜中磷钙的质量分数从2.1%增加到8.0%,膜的溶胀率从102%增加到144%,其在200～800 nm波长范围的吸光度也逐渐增加.当磷钙的质量分数为7.0%时,杂化膜的力学性能最佳,其拉伸强度为54.42 MPa、弹性模量为4045.72 MPa、断裂伸长率为4.85%.杂化膜的热分解温度为299℃,高于壳聚糖膜的分解温度290℃.这种具有层状磷钙结构的杂化膜具有良好的生物相容性,可作为一种潜在的支架材料.