Common Mode Voltage Reduction Using 3D-SVPWM for 3-level CI-NPC Inverter with Hybrid Energy System

This paper elucidates Common Mode Voltage (CMV) reduction in transformerless 3-phase 3-level Coupled Inductor Neutral Point (CI-NPC) Clamped Inverter with Hybrid Energy System. The three dimensional Space Vector Pulse Width Modulation (3D-SVPWM) with Nearest State Vector (NSV) is implemented to reduce the CMV by proper selection of medium, large and small vectors in 3D cubic space region. This NSV scheme in addition to CMV reduction, reduces the capacitor voltage balancing issues and minimizes switching losses. The proposed control provides full utilization of dc link voltage with reduced harmonics. This 3-level CI-NPC inverter is energized by hybrid energy source which includes photovoltaic system and wind energy system. The results obtained for the proposed scheme through simulation and experimental setup is compared with the conventional 2D-SVPWM and 3D-SVPWM scheme. From the compared results it is evident that the proposed scheme reduces CMV to a larger extent than 2D and 3D-SVPWM control. The simulation and experimental results are verified using matlab-simulink and FPGA-Spartan-6 controller respectively.     

基于二元水循环的水量-水质-水效联合调控模型开发与应用

为将我国最严格水资源管理制度的实践与二元水循环理论相结合，提高“三条红线”控制指标的科学性与合理性，本文以SWAT模型为基础，通过改进子流域划分方法、添加经济社会模块和人工用水模块，对其人工侧支循环模拟进行了系统的完善，开发了基于SWAT的水量-水质-水效联合调控模型SWAT_WAQER。以广西南流江流域为例，从国民经济用水量、河道径流与水质等方面对模型进行校验，并在此基础上划分了2030年“三条红线”控制指标。结果表明：该模型性能良好，能够用于不同节水情景下的国民经济用水量、污染物排放量、水功能区水质达标结果分析，可以作为科学制定“三条红线”控制指标的有力支撑工具。     

Looking ahead: Joint small group detection and tracking in crowd scenes

Small group detection and tracking in crowd scenes are basis for high level crowd analysis tasks. However, it suffers from the ambiguities in generating proper groups and in handling dynamic changes of group configurations. In this paper, we propose a novel delay decision-making based method for addressing the above problems, motivated by the idea that these ambiguities can be solved using rich temporal context. Specifically, given individual detections, small group hypotheses are generated. Then candidate group hypotheses across consecutive frames and their potential associations are built in a tree. By seeking for the best non-conflicting subset from the hypothesis tree, small groups are determined and simultaneously their trajectories are got. So this framework is called joint detection and tracking. This joint framework reduces the ambiguities in small group decision and tracking by looking ahead for several frames. However, it results in the unmanageable solution space because the number of track hypotheses grows exponentially over time. To solve this problem, effective pruning strategies are developed, which can keep the solution space manageable and also improve the credibility of small groups. Experiments on public datasets demonstrate the effectiveness of our method. The method achieves the state-of-the-art performance even in noisy crowd scenes.     

交流提升机可编程电控系统保护装置设置标准探讨

矿井提升机电控系统是一个典型而复杂的控制系统。在这里面，可编程控制器的作用可以说是表现得淋漓尽致。当前，焦作华飞、中矿传动、洛阳矿机、天津民意等以生产提升机电控系统为著称的厂家无小以可编程控制器为控制核心。笔者曾多次跟随集团公司外出检查，常听说因可编程电控系统保护装置设置问题出现这样或那样的问题，甚至发生了提升事故。可以说，提升机可编程电控系统保护装置设置因厂家而异，有很大的随意性，国家也无相关的标准设计规范。因此，笔者就交流提升机可编程电控系统保护装置的设置作以下探讨。     

JTDK－PC－01型交流提升机可编程电控系统

ＪＴＤＫ－ＰＣ－０１型交流提升机可编程电控系统是用可编程控制器作为主要控制器件，配以真空接触器、晶闸管整流电源等，构成了新一代交流提升机电控系统．分析讨论了该电控系统方案确定的原则和组成，介绍了应用效果．     

大冶铁矿球团厂煤气制造集散控制系统

介绍了以PLC为控制核心的集散控制系统的结构框图和功能，给出了系统的硬件配置、系统控制框图和软件实现。     

某火工装置延时失效原因分析与改进研究

为查找某火工装置延时失效的原因,进行了故障排查及失效机理分析。结果表明延时失效的根本原因为该火工装置结构设计不合理,导致在爆炸冲击波作用下装药密封受损,引起瞬发。对原装置进行了改进设计,并对改进后的火工装置进行了试验验证和可靠性评估,结果表明新装置延时正常,其综合可靠性达到了技术指标要求。     

基于PLC的后膛弹处废自动生产线

基于PLC的后膛弹处废自动生产线,由控制系统和机械设备组成.其工序流程分上弹、卸引信防潮塞、卸底火、拔弹、吹倒药和切割倒药等步骤.PLC控制机械设备的具体动作.上位计算机为监控核心,负责设备动作命令的发送和接收当前PLC状态反馈.传感器采集动作到位信息,文本显示器用于调试时的控制.软件采用自动和手动2种模式对生产线进行操作.     

机动式车载自适应光学波前处理器的设计

为满足机动式车载自适应光学系统的需求,设计了专用的波前处理器。该波前处理器采用波前处理主板、波前处理子板和DA转化板相结合的硬件架构,由光纤作为通信载体。在满足功能需求的同时提高了系统的可靠性;波前处理器是自适应光学系统闭环控制的运算中心,其运算延时直接影响系统的控制带宽。本文提出一种基于FPGA的多线流水自适应光学实时波前处理方法,实现了波前斜率计算、复原运算和控制运算。结果表明:对于两级精密跟踪,97个子孔径以及97单元变形镜的自适应光学系统,系统处理延时为506.25μs,满足系统1 500Hz的实时波前处理需求。     

变频器技术及其在煤矿中的应用

文中详细阐述了变频器技术和功能特点，及该技术在煤矿生产中构成的实用电机控制系统，并评述了它的应用前景。指出，该技术在风机、泵类等的电机控制系统中，可获得显著的节能效果。