2014年全国电压电流等级和频率标准化技术委员会主要工作

<正>全国电压电流等级和频率标准化技术委员会(TC1)(以下简称"电压电流及频率标委会")成立于1978年,负责全国电压、电流等级和频率等专业领域标准化工作,秘书处所在单位为机械科学研究总院中机生产力促进中心。1领域或行业情况     

基于电流传送器的正弦波振荡电路

提出了一种基于电流传送器的RC正弦波振荡电路。该电路只采用一个第二代电流传送器、两个电容和三个电阻,电路结构简单。本文详细分析了振荡器起振条件和振荡频率。理论分析与仿真结果表明,电路振荡频率可调且频率稳定。     

应用循环平稳方法分离电机系统故障

采用定子电流法对电机及其拖动设备进行扭振监测与诊断时，电流信号中频率成分复杂，不仅包含故障频率还有工频及其他信号成分，使用传统的信号处理方法难以将故障频率成分从中分离出来，造成诊断不准确。采用循环平稳的方法对电流信号进行解调，以去除电流信号中的工频干扰，同时对故障频率进行分离，达到更准确识别故障的目的。数据仿真和现场试验的结果表明，采用该种方法能够去除工频成分和分离故障信息，提高了采用定子电流法进行故障诊断的准确性。     

一种PWM整流器的电流自跟踪控制策略研究

针对PWM整流器中传统滞环电流控制方法因固定环宽而引起的功率管的开关频率变换剧烈、频率低时跟踪性差、频率高时开关损耗大等问题,对PWM整流器的电路拓扑、滞环电流控制方法下的电压环、电流环以及三相锁相环的工作原理进行了研究,对滞环电流的控制过程进行了归纳,提出了一种新型的电流自跟踪PWM控制策略,并对这种控制策略的作用机理进行了详尽的阐释。然后利用Matlab对电流自跟踪控制算法进行了系统仿真,同时又以数字信号处理器-DSP28035为核心,搭建了软、硬件平台,进行了实验验证。研究结果表明,电流自跟踪控制策略的输入电压与输入电流同相位,实际电流能够快速跟踪参考电流,能够实现功率因数校正,该种控制策略具有可行性和有效性。     

电主轴定子电阻特性分析

影响定子电阻变化的因素有温度、运行频率、定子电流,负载。找到定子电阻随着这些因素的变化规律,有利于找到精确的定子电阻辨识方法,从而提高电主轴控制系统的精度及可靠性。论文用实验的方法采集空载和加载时温度、频率、定子电流及定子电阻数据。通过对数据的处理分析得出,空载时,定子电阻随温度、定子电流、频率的变化呈非线性变化。加载时,定子电流随着载荷的增大线性增大,加载实验后期定子电阻随着载荷的增大线性增大。     

功率超声电源谐振频率自动跟踪技术

本文针对匹配网络对压电超声换能器谐振频率影响问题,介绍了具有电流反馈式频率跟踪功能的超声发生器的系统结构,阐述了电流反馈式频率跟踪的原理,基于AT89C52设计了相应的硬件控制电路,实现了电流反馈式频率自动跟踪方法,具有实际的工程应用价值。     

LCL型有源电力滤波器并网电流控制研究

APF的控制关键就是对输出电流及直流侧电压进行控制,L,LC型并网的并网电流由于开关频率受限,并网电流含有较大的开关频率附近的谐波电流,同时滤波电感过大导致设备体积大,成本高,并影响并网控制的动态性能.LCL型滤波器有着更好的效果,该文就LCL型滤波器PI控制的稳定性,内电感电流跟踪特性,并网电流跟踪特性和电网电压抑制特性进行了深入研究,得出了并网指标对闭环根频率的技术要求.     

一种高精度I／F变换器的研究

捷联惯导系统中的加速度计是重要的惯性测量器件,其输出通常为模拟信号电流,目前电流的测量精度提高受到限制。本文通过电流频率变换器将其变换为与周期成正比的脉冲信号从而更精确的测量并且更便捷的采集数据。本文介绍了一种采用电流电压变换模块,AD模数转换器和AVR单片机构成的高速、高精度的电流频率变换系统,从而将传统的I／F变换精度从10-3提高到10-5。     

一种高精度I/F变换器的研究

捷联惯导系统中的加速度计是重要的惯性测量器件,其输出通常为模拟信号电流,目前电流的测量精度提高受到限制。本文通过电流频率变换器将其变换为与周期成正比的脉冲信号从而更精确的测量并且更便捷的采集数据。本文介绍了一种采用电流电压变换模块,AD模数转换器和AVR单片机构成的高速、高精度的电流频率变换系统,从而将传统的I/F变换精度从10-3提高到10-5。     

基于Adaline神经网络的家用电器谐波分析

为了分析常用家用电器用电对公共电网的谐波污染,应用Adaline神经网络对其进行自适应谐波分析。改进的增强型Adaline神经网络将频率作为待定权值,同时估计被测信号的频率、幅值和相位。幅值相位权值的学习采用变步长方法,频率权值的学习采用动量项方法,提高了收敛速度。修正的频率调整公式和频率延迟调整策略简化了频率学习率的设置。基于实测电压信号的对比研究验证了改进算法的收敛性能和分析精度。通过数据采集实验装置得到计算机、电视机、洗衣机、微波炉等家用电器的用电波形,并用改进的Adaline方法对波形信号进行谐波分析。实验结果表明,计算机的电流谐波总畸变率超过60%,微波炉的电流谐波总畸变率在40%以上,电视机和洗衣机的电流谐波总畸变率在10%以上。     

转炉下渣自动挡渣技术的研究与应用

针对采用传统人工肉眼判断钢渣比这一方式,手动操作转炉滑动出钢口存在诸多弊端,借鉴红外热成像技术,设计了转炉下渣自动检测设备系统,该设备系统借助红外传感器对钢流进行无接触式的图像采集并分析处理,从而实现了对转炉出钢状态的实时监测。利用可靠的转炉下渣自动检测系统并结合转炉滑动出钢口,实现了转炉的自动挡渣作业。     

SYSTEM FOR TORQUE CONVERTER DESIGN AND ANALYSIS BASED ON CAD/CFD INTEGRATED PLATFORM

A 3D torque converter design system is developed based on numerical investigation into flow field and CAD technology. The 3D steady-state flow field simulation is undertaken by using time averaged Reynolds equation and k-epsilon turbulence model, with mixing-plane boundary conditions at three section interfaces. The blades are designed according to the flow field characteristics by using a reverse design method in the system. The accurateness of numerical analysis and the validity of design system are verified by the fluid field experiment of desingn example of the torque converter. This kind of design and analysis system for torque converter based on integration of comput ationol fluid dynamics （CFD） and CAD is a powerful tool for torque converter manufacturing, but also a prettg important significance for research and development.     

A Data Stream Converter for a Radio Telescope with a Wideband-Signal Digital Recording System

A data-stream converter makes it possible to connect a radio telescope with wideband (512 MHz) signal-recording channels to active very-long-baseline interferometers using multichannel recording systems for narrowband (16 or 8 MHz) signals. A digital converter based on a field programmed gate array (FPGA) selects and formats up to 16 narrowband signals.     

A digital signal converter for radio astronomical systems

A digital signal converter operating in a video frequency band (up to 32 MHz) and intended for radio astronomical equipment is based on an LTC2288 analog-to-digital converter and an XC4VSX25 field programmed gate array. A two-band base band converter improving parameters of the radio interferometric terminal, a two-channel spectrometer minimizing times of observation of radio-frequency sources in spectral lines, and a radiometer for recording signals in a continuum operating under the action of radio interference have been designed using the converter. The advantages of this equipment are confirmed by results of tests at the Svetloe radio astronomical observatory.     

电动汽车用高效率DC/DC电源变换器设计

为提高电动汽车用电源变换器效率,采用同步整流技术,设计一台基于BUCK电路的直流电源变换器。设计出变换器主电路和控制电路,计算变换器满载输出效率,并制作一台42V输入,12V/30A输出样机,实测样机满载输出效率达95.48%。     

基于贝努力映射和CPLD的混沌A/D转换器

本文分析了基于贝努力映射的混沌A／D转换器的工作原理，给出了初值计算方法。设计了仿真电路，分析了理想参数情况下，该混沌A／D转换器的误差。采用CPLD设计了实验电路，分析了实验电路的转换误差，指明了改进混沌A／D转换器性能的方向。为混沌A／D转换器的理论研究和实用化进行了有益探索。     

基于柔性直流阻尼控制器与附加励磁阻尼控制器协同抑制次同步振荡研究

针对包含模块化多电平换流器型直流输电(MMC_HVDC)的交直流混合输电系统中出现的次同步振荡(SSO)问题,对基于MMC_HVDC的次同步阻尼控制器(MMC_SSDC)与附加励磁阻尼控制器(SEDC)的协同抑制问题进行了研究。首先针对待研究的交直流混合输电系统,设计了MMC_SSDC和SEDC的结构并针对实际算例整定其相位补偿及增益参数;然后分别从理论分析和系统电气阻尼特性的矢量叠加关系方面对MMC_SSDC和SEDC协同抑制策略的可行性进行了研究;最后在PSCAD/EMTDC上搭建模块化多电平换流器为335电平的交直流混合系统时域仿真模型,仿真结果验证了结论的正确性和协同抑制方案的有效性。研究结果表明:MMC_SSDC和SEDC在增加系统电气阻尼的效果上不仅不会相互影响且基本满足矢量叠加关系,利用两者协同抑制SSO的方案是可行的。     

A new protection strategy of impressed current cathodic protection for ship

Corrosion is never avoided in the use of materials with various environments. The underwater hull is normally protected against rusting by several coatings of anti-corrosive paint. The purpose of ICCP (impressed Current Cathodic Protection) system is to eliminate the rusting or corrosion, which occurs on metal immersed in seawater. The anode of ICCP system is controlled by an external DC source with converter. The function of anode is to conduct the protective current into seawater. The proposed algorithm includes the harmonic suppression control strategy and the optimum protection strategy and has tried to test the requirement current density for protection, the influence of voltage, the protection potential. This paper was studied the variation of potential and current density with environment factors, time and velocity, and the experimental results will be explained.     

Sliding mode current control of a NOCULL converter based on hysteresis modulation method in a wide range of operating conditions

This study presents a novel control scheme for voltage regulation of a negative output cascade ultra-lift Luo converter (NOCULLC). Due to the complicated high order model of the converter, its performance is degraded against large load variations, input voltage changes and parametric uncertainties. In order to enhance the converter behavior, a PI compensator and a sliding mode current controller are combined to control the fourth order NOCULLC worked in a wide range of operating conditions. Because of the non-minimum phase structure of the converter, the output voltage of the converter is indirectly regulated by enforcing the input inductor current to track its reference signal. The sliding mode current controller improves the dynamic and static performances of the converter by minimizing the inrush current of the input inductor of the converter and also, the PI controller eliminates the steady state error of the output voltage of the converter. The closed loop system stability is demonstrated by using sliding mode theory. Furthermore, this paper proposes a systematic procedure to compute the gains of the controller based on the stability constraints which guarantees robustness of the developed controller. The experimental results show the robustness and effectiveness of the proposed controller against parametric variations and uncertainties of the converter. Also, a comprehensive comparison of the general aspects of the properties between the developed method and other existed controllers is provided.     

一种混合型移相全桥DC-DC变换器的仿真研究

在实际的应用生产中,传统移相全桥DC-DC变换器被广泛应用在大、中功率场所。由于其往往采用全桥型整流器,它们在低压应用系统中得不到很好的效率优化,故而并不适用。针对该问题,采用一种基于两个具有中心抽头变压器和谐振中路的混合形移相全桥变换器（HYPSFB）,分析了该移相全桥变换器的工作原理及相应特征,该变换器具有变压器利用率高,开关器件损耗小等。在MATLAB/Simulink环境下建立了仿真系统,并进行仿真分析和给出仿真结果。