宝泉抽水蓄能电站的特殊设备和特殊保护

宝泉抽水蓄能电站为适应机组在发电和抽水工况的不同磁场旋转方向,设置了换相闸刀、被拖动闸刀、拖动闸刀、起动母线及特殊设备,并针对各种特殊工况下的非常运行方式,设置了电压相序监视保护、低频保护、低功率保护、逆功率保护、低频过流保护及定子保护。从而实现其调峰填谷、调节电压频率及事故备用等功能。     

Fast switch fault diagnosis for PWM DC–DC low power converters

In this paper, a fast switching fault diagnostic scheme is proposed for low‐power pulse width modulation (PWM) DC–DC converters operating in different conduction modes. The outstanding feature of the proposed scheme is that no additional sensing circuits are needed. This is achieved by using the differential of output ripple voltage and the switch gate driver signal for diagnosis. Since the output voltage has to be normally measured for control purposes and the PWM signals are known to the controller, no additional sensors are needed in the proposed scheme. Moreover, based on the real‐time output voltage measurement and switch gate driver signal, the characteristics of switch open‐ and short‐circuit faults can be rapidly extracted, specifically, in less than one switching cycle. Besides, the fault detection scheme can be implemented by a low‐cost logical hardware circuit, which can be integrated into the control unit. The fault diagnosis principle, design considerations, and implementation of the detection scheme are discussed in this paper. Experimental results show that the fault detection system can detect the switching fault in four‐tenths of the switching period. Besides, the proposed method can be used in the applications where the output voltage ripple rate is more than 4%, which covers most situations. © 2017 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

The role of response repetition in task switching.

When switching between tasks, participants are sometimes required to use different response sets for each task. Thus, task switch and response set switch are confounded. In 5 experiments, the authors examined transitions of response within a linear 4-finger arrangement. A random baseline condition was compared with the cuing of specific response subsets grouped by hand or by finger equivalence, and these subsets were examined in both single task and task-switching designs. Results showed that part of the task switch cost is associated with switching between response sets. Furthermore, the analysis revealed a novel effect: When task switching and repetition trials are mixed, a bias towards switching the response and/or hand is found in task repetition trials. Response repetition is hindered when a task switch is expected, even for those trials when a switch of task does not occur. The results demonstrate executive processes involved in task set configuration closely depend on the motoric processing of the response set. The results are also important for current theories of task set control. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A Nanoindenter Based Investigation of Gold–Ruthenium Alloy Microcontact Behavior under Cyclic Condition

Abstract

A nanoindenter based experimental setup was used to characterize gold–ruthenium (Au5%Ru) microcontact behavior under cycling and hot-switching conditions where a cantilever beam with a contact bump was cycled in and out of physical contact with a flat plate to simulate the action of MEMS ohmic contact switches. Cantilever beam and flat plate were fabricated from silicon, and then sputter coated with 300 nm of Au5%Ru as the contact material. All contacts failed in adhesion with either shorter fatigue life (about 1–2 million cycles) or longer life (about 6 million cycles). The smoother contact surface had shorter fatigue life. The Au5%Ru contact material had longer life and higher resistance than gold. Further, contact resistance was constant during cycling up to failure. Different contact parameters: adhesion force, threshold force, strain hardening/softening and plastic deformation were monitored during cycling. Adhesion force in Au5%Ru microcontact was smaller than in gold. Threshold force was larger in Au5%Ru than in gold. Time-dependent and plastic deformations as well as cyclic softening were observed in Au5%Ru. Thus, elastic-viscoplastic material model(s) with strain softening capability are needed for the analysis of Au5%Ru microcontact behavior.     

锦纶6细号短纤维的工艺研究

介绍了锦纶6细号短纤维的开发研制过程，以及所采取的主要技术措施和工艺。     

Simulation of quantum-ballistic nanoswitches

A two-dimensional model based on the solution of the Schrödinger-Poisson system in effective-mass formulation is proposed for the calculation of quantum-ballistic transport processes in nanoswitch structures. The method is appropriate to properly describe the strong confinement of the electrons in the heterostructure. Using scattering boundary conditions an energy-dependent transmission matrix is calculated that allows us to determine the total charge density of all electrons injected into the device by integration over energy. In this approach space charge effects are self-consistently taken into account. The practicality of the model for numerical simulation is demonstrated with reference to measured data for various device geometries. We find that for device structures such as the Y-branch switch non-linear effects are of crucial importance.     

一种改进的模糊神经网络方法判定沉积微相的研究

将模糊神经网络模式识别技术应用于利用测井曲线进行单井沉积微相的划分,增强了根据测井数据识别沉积相的能力,大大提高了工作效率。     

An area-efficient VLSI implementation for programmable FIR filters based on a parameterized divide and conquer approach

In this paper, we propose an optimal VLSI implementation for a class of programmable FIR filters with binary coefficients, whose architecture is based on a parameterized divide and conquer approach. The proposed design is shown to be easily extendable to FIR filters with multibit coefficients of arbitrary sign. The area efficiency achieved in comparison to direct form realization is demonstrated by VLSI implementation examples, synthesized in TSMC 0.18-μm single poly six metal layer CMOS process using state-of-art VLSI EDA tools. The possible saving in average power consumption is estimated using gate-level power analysis. Suggestions for applications and topics for further research conclude the paper.     

基于开关组的禁忌算法在配电网动态重构中的应用

首先定义了一种基于重构次数的配电网优化模型，提出一种基于开关组的禁忌搜索算法求解优化模型。该方法用开关组状态作为编码的网络结构部分，减小了决策变量维数和不可行解的数量;用三进制时间码作为编码的时间部分，统一了码位取值范围，方便了禁忌表长度和终止条件的确定。另外，利用禁构规则来指导禁忌算法中邻域的生成，既减少了候选解个数，又避免了禁忌搜索中死循环的产生，大大提高了搜索的效率和质量。最后，通过与其他方法的比较，验证了所述算法的快速、有效性。     

一起GIS断路器非全相运行的故障分析和处理

隔河岩电厂4号发电机组500 kV出口断路器在一次分闸过程中,由于液压机构故障引起开关B相未分开而发生非全相运行故障,检查发现是由于GIS部件老化所致,对其采取了处理措施,取得了较好的效果。