阳极铝箔交流腐蚀发孔对比容的影响

采用５０Ｈｚ交流电腐蚀发孔和进一步腐蚀阳极铝箔，在腐蚀箔表面形成透明钝化型腐蚀膜且蚀孔孔径较大。在交流电腐蚀过程中不产生发黑、掉粉和减薄现象。另外，该工艺对盐酸浓度和硫酸添加剂浓度的适应范围很宽。     

中频交流脉冲等离子体源的研究

采用中频交流脉冲等离子体源进行了抑制弧光放电和空心阴极效应以及离子渗氮工艺的实验。结果表明,交流脉冲放电在抑制弧光放电和空心阴极效应方面是非常有效的,对于高铬钢材料表面的离子渗氮作用是明显的。它为解决材料表面处理中的难点(小孔、深孔、狭缝的处理)提供了一种新的探索方案;也为等离子体技术应用领域中处理不导电的基体或薄膜以及磁控溅射新工艺(交流孪生溅射技术)提供了研究设备。     

交流变频器共直流母线方案的模型分析

交流变频器的共直流母线方案在现代许多工业中很受欢迎，这得益于该运行方式能大幅度节省费用、减少空间以及具有更高的可靠性。本文将通过模型来分析不同共直流母线方式下的预充电、电动和发电过程，并同时指出了选用怎样合适的部件可以避免母线连接后的问题发生，最终确保无故障运行。     

基于MATLAB/Simulink的交流伺服系统的仿真

交流伺服系统是一种复杂的非线性时变系统。文中介绍了应用MATLAB/SIMULINK可视化动态仿真平台进行软件伺服的系统仿真方法。该方法采用易扩展的模块化设计,可在线修改和观察所有参数以及参数变化对系统控制效果的影响,从而能方便地验证各种控制策略,并据此选出高效的快速设计方案,缩短了研制周期,对系统设计和调试起到了很大的作用。     

Mechanical and AC loss properties in mono-and multi-filamentary Bi-223 Ag-sheathed tapes

The evaluation of the bending strain tolerance and AC loss properties for monoand multi-filamentary Bi-2223 Ag-sheathed tape were carried out at liquid nitrogen temperature. For tapes with a filament number of over 19, the critical current (I_c) was maintained at the same values up to the bending strain of 0.3%, although the I_c of the mono-filamentary tape at the condition of 0.2% strain degraded to 90% of the value for the no-strain condition. The AC loss of the monofilamentary tape was the hysteresis type. On the contrary, the AC loss of the multi-filamentary tape was substantially dominated by the eddy current loss in the Ag matrix.     

A parametric yield model

Assuming that the distribution of path delays introduced by variations in the manufacturing process is exponential instead of gaussian, the interdependence problem between delay-optimization of synthesized networks and parametric yield has been revisited. The result confirms the claim of Williams, Underwood, and Mercer. The exponential distribution is the consequence of simultaneous occurrence of gate delay faults along the path.     

Single-stage three-phase boost power factor correction circuit for AC–DC converter

This article presents a single-stage three-phase power factor correction (PFC) circuit for AC-to-DC converter using a single-switch boost regulator, leading to improve the input power factor (PF), reducing the input current harmonics and decreasing the number of required active switches. A novel PFC control strategy which is characterised as a simple and low-cost control circuit was adopted, for achieving a good dynamic performance, unity input PF, and minimising the harmonic contents of the input current, at which it can be applied to low/medium power converters. A detailed analytical, simulation and experimental studies were therefore conducted. The effectiveness of the proposed controller algorithm is validated by the simulation results, which were carried out using MATLAB/SIMULINK environment. The proposed system is built and tested in the laboratory using DSP-DS1104 digital control board for an inductive load. The results revealed that the total harmonic distortion in the supply current was very low. Finally, a good agreement between simulation and experimental results was achieved.     

光伏并网发电模拟装置研制

文中研制了一套模拟并网发电系统,实现了频率跟踪、最大功率跟踪、相位跟踪、输入欠压保护、输出过流保护、反孤岛效应等功能;采用Atmega16高速单片机,实现了内部集成定时、计数器功能;利用定时器T/C2的快速PWM功能,实现SPWM信号的产生;采用T/C1的输入捕获功能,实现了频率相位监测和跟踪以及对失真度、输入电压、输...     

对称电极组空间位阻效应交流电渗流研究

建立了一种对称电极组交流电渗流微泵结构,通过改变相邻电极间的AC信号相位,可以方便地实现对微通道流向的控制。根据双电层离子数的空间位阻效应修正,数值求解了双电层Poisson-Boltzmann方程和液体流动Navier-Stokes方程,得到了对称电极组交流电渗微泵的流动特性。分析了微泵流速与交流电压幅值、频率等参数的关系特性,并与双电层Debye-Hückel线性解进行比较。结果表明,空间位阻效应修正在低电压时与Debye-Hückel线性解一致,但是在高电压时会产生高频反向流。     

基于Matlab的异步电动机矢量控制系统的仿真研究

在分析Matlab／Simulink环境下电力系统工具箱（Powerlib）中各元件的运行原理的基础上，采用状态空间表示方法对异步电动机矢量控制系统进行建模和仿真，分析了Simulink模块和Powerlib元件的不同本质。最后通过实例给出了交流异步电机矢量控制系统的仿真建模方法。