基于Stateflow电力机车变流器控制设计与实现

某出口型号交流电力机车牵引控制系统要求变流器控制逻辑具备接触器控制、牵引系统数据交互、变流器故障保护、变流器启动自检等功能。针对以上功能,基于MATLAB中的Simulink/Stateflow可视化编程工具进行牵引控制模型的搭建,遵循模块化编程理念,采用较少的程序代码编写实现复杂的逻辑控制模型,生成逻辑清晰的控制功能流程图,进行半实物仿真测试,增强控制模型的可靠性。通过该变流器产品型式试验检验,验证变流器控制逻辑的功能可以满足控制系统的需求。     

一种可控的自动扶梯电磁铁驱动电路板

扶梯制动系统是扶梯在出现紧急状况下确保乘客安全的重要设施。制动系统中的安全制动是在工作制动器无法在规定的时间内制停扶梯的一个措施,往往是在一些特别危险的场合下被触发,因此对于此制动器的控制显得尤为重要。本文提出了一种新型的自动扶梯制动器电磁铁驱动电路的设计,该设计用纯电子线路替代了传统的电气与电子组合形式,直接由自动扶梯单片机控制单元进行控制。     

QKD系统中基于EA电路的诱骗态实现

使用诱骗态量子秘钥方案可以解决因光子数分离攻击而导致的安全漏洞,保证了长距离量子通信的安全。本文介绍了量子通信的相关原理,通过对电吸收调制电路和激光器驱动电路的设计,精确控制产生了1550 nm波段的窄脉冲,经过内部调制成功制备诱骗态光脉冲,其强度约为信号态光脉冲的三分之一,因激光器的同一性而具有一致的光学特征从而避免了时频窃听,并具有强度可调的优点。     

Numerical investigations on the Dish–Stirling engine system

The Stirling engine is an environmentally friendly external combustion heat engine and reduces the complexities of the combustion process, and indirectly helps in reduction of CO₂ emission. Modelling based on cyclic analysis is performed for a Beta configuration Stirling engine of 1.5?kW_e capacity using a rhombic drive for the solar-dish-supported Stirling engine. The analysis helps in estimating the overall efficiency of the system using the experimental correlation of the solar concentrator ARUN160 at the engine operating temperature. The analysis shows that the system will have overall efficiency around 25% in the range of 750–1050?K at the expansion space. The degradation of performance compared to that at an operating temperature of 1025?K is only marginal and makes 750?K a more preferred temperature. The present study evaluates a range of possible design goals and provides suitable alternatives and thus provides a clear understanding of the system design considerations.     

电驱液压式大截面导线压接设备自动化研究

现有的压接设备可控性差、操作复杂,导致压接质量因人而异。针对此问题,提出了基于DDVC技术的导线压接设备自动化控制方案,建立了速度控制系统数学模型,应用Simulink进行仿真,分析系统性能。建立了基于DEFORM的耐张线夹压接实验模型,获得了耐张线夹压接的最佳加载速度曲线,并以此作为压接设备速度控制系统的Simulink仿真模型输入,对压接过程进行了仿真分析。结果表明:开环控制时系统存在一定的超调,加入PID控制后可有效抑制超调;所设计的压接设备可很好地跟随最佳压接曲线,跟随误差仅为0. 904 mm·s-1。研究成果对改进压接设备、提高压接质量提供了新的解决方案。     

初始制动时预测湿式制动器热对流特性的积分方法

湿式制动器对重型车辆安全具有关键影响，以湿式制动器摩擦副间隙的冷却液压油（Automotive transmission fluid，ATF）为研究对象，考虑车辆初始制动阶段流体的黏性摩擦和层流流动特征，利用积分方法建立了摩擦副流体的非稳态能量方程，并获得了能同时满足轴向和径向边界条件的三维温度和热流密度显式解析表达式，通过简化动量方程和多项式分布假设也获得了径向速度和压力的理论解，与以往试验对比表明，压力和温度解析解与试验结果具有较好的一致性，理论模型有望推广用于液黏离合器等其他HVD装置的ATF速度场、温度场和热流密度场的理论预测。     

油藏中后期减氧空气驱提高采收率机理研究

尕斯库勒油田E¹₃油藏已经进入高含水时期，储采失衡加剧，综合含水率达到了80%以上，原油产量下降，经济效益变差。为了提高油藏原油采出程度、改善油藏开发效果，调研了国内外减氧空气驱的机理研究以及现场试验的资料，建立了以油藏真实孔渗饱数据为基础的一维条形地层机理模型，并选取该油藏Y12-27井组进行了减氧空气驱可行性验证。研究表明:纵向顶部减氧空气驱驱油效果优于水驱和氮气驱；驱替压力对原油采出程度影响不大；注水转注气可以提高原油采出程度；对于减氧空气驱，由于低温氧化反应的作用，氧气浓度对原油采出程度有一定影响，但比较微弱，其中，氧气浓度为10%时，驱替结束采出程度最高；尕斯库勒油田E¹₃油藏属于注水开发“双高”油藏，适用于减氧空气驱；对于该油藏Y12-27井组，顶部减氧空气驱驱油效果好于水驱和氮气驱，建议氧气浓度超过10%时采取关井等措施。     

手机保护套模内热切模具设计

针对传统冷流道模具需要人工去除浇注系统凝料和冷切浇口技术效果不佳的现状，以某智能手机保护套为例，设计了具有热切浇口功能的手机保护套模具。首先根据产品搭接侧浇口的结构特点，设计了能够将浇口切除干净，且运动准确的切刀装置，并利用有限元分析方法确立了合适的进刀时间和驱动油缸。然后设计了合理的顶出和冷却机构，保证产品和浇注系统凝料在分离冷却后分别被安全顶出。     

State feedback integral control for a rotary direct drive servo valve using a Lyapunov function approach

This paper concerns a state feedback integral control using a Lyapunov function approach for a rotary direct drive servo valve (RDDV) while considering parameter uncertainties. Modeling of this RDDV servovalve reveals that its mechanical performance is deeply influenced by friction torques and flow torques; however, these torques are uncertain and mutable due to the nature of fluid flow. To eliminate load resistance and to achieve satisfactory position responses, this paper develops a state feedback control that integrates an integral action and a Lyapunov function. The integral action is introduced to address the nonzero steady-state error; in particular, the Lyapunov function is employed to improve control robustness by adjusting the varying parameters within their value ranges. This new controller also has the advantages of simple structure and ease of implementation. Simulation and experimental results demonstrate that the proposed controller can achieve higher control accuracy and stronger robustness.     

A Restart Control Method for Position Sensorless PMSM Drive Systems Without Potential Transformer for Railway Vehicle Traction

This paper proposes a restart control method for position sensorless PMSM drive systems without a potential transformer for railway vehicle traction. This method can estimate the initial rotor speed and position under coasting conditions over the entire speed range. The method can also be used when the back‐EMF voltage is higher than the inverter DC link voltage. The proposed method is verified by experiments using a 200‐kW PMSM.