高速储能飞轮用无铁心永磁无刷直流电动机的分析与设计

采用电磁场的数值计算方法,对比分析了常规磁体结构和HALBACH磁体结构的外转子无定子铁心永磁无刷直流电机,重点分析了磁体厚度变化对两种磁体结构电机气隙磁通密度、磁通及转子轭部磁通的影响,认为HALBACH磁体结构特别适于外转子高速飞轮用无铁心电机.提出HALBACH磁体结构电机的场路结合设计计算方法,并通过一25Nms角动量(30000r/min额定转速)的高速外转子飞轮用无铁心永磁无刷直流电动机进行了试验验证.     

自采样比例积分控制全数字锁相环的性能分析和实现

提出了一种基于自采样比例积分（PI）控制的全数字锁相环（ADPLL）,并对该锁相环进行了详细的理论分析和仿真验证,最后用现场可编程逻辑器件（FPGA）予以实现.由于采用了自采样比例积分控制策略,使该锁相环在不同的锁频点具有几乎相同形式的传递函数,有利于理论分析和环路设计.理论分析、仿真验证和试验结果都表明该全数字锁相环具有环路参数设计简单、跟踪范围广、跟踪速度快、系统稳定性好、控制灵活等优点.该设计方案可以作为一个子系统或功能模块用来构成片上系统（SoC）,用以提高控制系统的可靠性、简化系统的硬件结构.     

站域信息实时同步采集中同步采样时钟的设计

站域信息实时同步采集是智能变电站中实现全景信息采集的关键技术。在研究基于全球定位系统(GPS)采样数据同步的基础上,针对合并单元同步采样时钟对晶振依赖性强,及在晶振老化、频率准确度降低的情况下输出误差较大等不足,提出了一种基于现场可编程门阵列(FPGA)的同步采样时钟闭环校正实现方法。通过对2种同步采样时钟输出误差的定量分析,证明可通过软件补偿改善输出误差,并在提高同步采样脉冲输出精度的同时,保证输出相位的一致性。实验验证表明,该方法在使用普通石英晶振时,合并单元的同步采样值能达到0.2s级精度,体现了良好的同步性能。     

局部阴影下光伏阵列MPPT控制方法的研究

光伏阵列在局部阴影条件下,其输出P-V特性曲线将呈现多个功率峰值。为了追踪到全局最大功率点,对局部阴影条件下光伏阵列输出P-V特性曲线进行了深入分析,对各功率极值点对应电压和被遮挡的光伏组件个数及光照强度之间的关系进行了研究。得出了相邻功率极值点对应电压之差的最小值为0.8Uoc(Uoc为单个光伏组件的开路电压)等规律,在这些规律的基础上,提出了一种新的最大功率点跟踪方法,能够快速、准确地跟踪到全局最大功率点。应用MATLAB软件搭建了仿真模型,仿真结果验证了所提出方法的正确性和有效性。     

Measurement of propagation velocity driven by current microstimulation in the mouse auditory cortex in vitro

All sensory cortical areas, including the auditory cortex, are considered to be wired according to the same general laminar structure schema, commonly referred to as the canonical model of cortical circuitry. The auditory cortex in vivo , however, is functionally anisotropic; the functional organization along the tonotopic axis is qualitatively different from that orthogonal to this axis. In the current study, we examined whether the functional anisotropy of the auditory cortex observed in vivo is reflected in propagation activity driven by electric stimulation in the local microcircuitry in vitro . Using in vitro preparations of coronal and angled horizontal brain slices, we directly investigated their isotropic versus anisotropic properties using microstimulation and multi‐site recording with a multielectrode array substrate. Our results clearly demonstrated the isotropic properties of the circuits in slice preparations of the auditory cortex. Additionally, we found that driven by stimulation current in layer 4, the horizontal velocity of activity propagation in layer 2/3 was faster than the vertical velocity from layer 4 to layer 2/3 and the horizontal velocity in layer 4. On the basis of these results, we discuss the local network and its possible functions in the auditory cortex. © 2017 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

Two-Level Designs to Estimate All Main Effects and Two-Factor Interactions

We study the design of two-level experiments with N runs and n factors large enough to estimate the interaction model, which contains all the main effects and all the two-factor interactions. Yet, an effect hierarchy assumption suggests that main effect estimation should be given more prominence than the estimation of two-factor interactions. Orthogonal arrays (OAs) favor main effect estimation. However, complete enumeration becomes infeasible for cases relevant for practitioners. We develop a partial enumeration procedure for these cases and we establish upper bounds on the D-efficiency for the interaction model based on arrays that have not been generated by the partial enumeration. We also propose an optimal design procedure that favors main effect estimation. Designs created with this procedure have smaller D-efficiencies for the interaction model than D-optimal designs, but standard errors for the main effects in this model are improved. Generated OAs for 7–10 factors and 32–72 runs are smaller or have a higher D-efficiency than the smallest OAs from the literature. Designs obtained with the new optimal design procedure or strength-3 OAs (which have main effects that are not correlated with two-factor interactions) are recommended if main effects unbiased by possible two-factor interactions are of primary interest. D-optimal designs are recommended if interactions are of primary interest. Supplementary materials for this article are available online.     

基于激光点阵列探测的多光轴平行性外场测试方法

提出一种红外、可见光、激光三轴平行性检测的外场测试方法。在可见十字靶线和红外十字靶线重合的测试靶上,点列阵分布激光点源探测器。以重合的十字靶线为基准,点列阵探测器接受激光照射,精确定位激光光斑中心,获取激光发射轴与可见、红外十字靶线的偏差,实现多光轴的平行性检测。设计结果表明：在待测系统最远探测距离范围内,测试距离越远,平行度检测精度越高,在1.5km测试距离,激光与红外、电视光轴的平行度检测精度小于5″。     

薄层油膜在电解质溶液中的导电机制转变

薄层油膜在电解质中的电位变化是一个电化学过程，采用组合式微电极研究了薄层油膜在5％Na2SO4溶液中导电机制转变行为。结果表明：薄层油膜在电解质溶液中存在导电机制由电子导体向离子导体转变现象，表现为薄层油膜在浸泡初期，电位随时间变化发生正移，当浸泡一段时间后，薄层油膜的电位开始随时间变化发生负移，理论分析说明：当油膜为电子导体时，所测得的电位值实际上反应了电解质溶液中的氧化剂在油膜／电解质界面发生还原反应时的平衡电位，当油膜为离子导体时，所测得的电位值实际上反应了金属在金属／油膜界面发生氧化反应时的平衡电位，因此，采用组合式微电极，通过对薄层油膜电位的精确测量，可以研究高阻薄膜（如薄层油膜）在电解质溶液中导电机制转变。     

任意分散布阵短波通信干扰机空间功率合成技术

介绍了随意分散布站短波通信干扰机空间功率合成系统的基本原理和主要技术，给出了系统仿真和试验结果．该系统以短波通信干扰机为阵列单元，采用随机稀布阵数字发射波束形成技术将多台干扰机的功率在空间进行合成，达到增强干扰功率的目的，同时由于采用任意分散布站，使得该系统具有更强的实用性．     

基于FPGA的模拟信号源系统设计

提出了一种基于现场可编程门阵列(FPGA)的全球定位系统(GPS)卫星信号模拟源系统的设计方案。FPGA作为一种常用的可编程器件,将其应用到模拟信号源系统中,并配合射频模块,实现了多个频点的程序控制,产生出大量具有高稳定度和准确度的不同频率的GPS卫星信号,减少了多个频点的开发周期,降低了风险。