某型号旁通阀内部清洁度的清洗次数验证

对某型号旁通阀进行处理并经过试验验证,探索出该型号旁通阀的清洗次数与清洁度等级的对应关系,为今后类似试验提供了参考。     

地铁列车制动缓解旁路电路的改进

为解决现有地铁列车制动缓解电路和制动缓解旁路开关存在的问题,本文通过对制动缓解旁路电路的详细分析,提出在旁路开关失效的情况下,使得列车收到空气制动和停放制动已缓解信号的改进方法,有效地降低了行车大间隔事故和救援事故发生的频率.     

Finite element formulation of smart piezoelectric composite plates coupled with acoustic fluid

In the context of noise and vibration reduction by passive piezoelectric devices, this work presents the theoretical formulation and the finite element (FE) implementation of vibroacoustic problems with piezoelectric composite structures connected to electric shunt circuits. The originalities of this work concern (i) the formulation of the electro-mechanical-acoustic coupled system, (ii) the implementation of an accurate and inexpensive laminated composite plate FE with embedded piezoelectric layers connected to resonant shunt circuits, and (iii) the development of an efficient fluid-structure interface element. Various results are presented in order to validate and illustrate the performance of the proposed fully coupled numerical approach.     

An Inductor-less Sub-mW Low Noise Amplifier for Wireless Sensor Network Applications

This paper presents a Sub-mW differential Common-Gate Low Noise Amplifier (CGLNA) for ZigBee standard. The circuit takes the advantage of shunt feedback and Dual Capacitive Cross Coupling (DCCC) to reduce power consumption and the bandwidth extension capacitors to support 2.4 GHz ISM band. An amplifier employing these techniques has been designed and simulated in 0.18 µm TSMC CMOS technology. The Simulation results show a gain of 18.2 dB, an IIP3 of −4.32 dBm and a noise figure of 3.38 dB at 2.4 GHz. The proposed LNA consumes only 967 µW from a 1-V supply.     

基于LCL滤波器的高稳态性能并联有源电力滤波器

并联有源电力滤波器(APF)适用于补偿电流源型谐波,通常由于谐波电流较大的变化率以及电流环的稳态误差,进行高精度补偿具有一定难度。本文采用LCL滤波器兼顾补偿电流带宽和开关纹波的滤除效果,从补偿电流变化率和滤波电容高频分流的角度详细讨论了滤波器的设计方法。同时,将重复控制直接应用于LCL滤波器的补偿电流控制,带有惯性的微分补偿器保证了控制环的稳定性和稳态精度。采用上述措施后,补偿后的电网电流在高、低频段都有较低的谐波含量。实验结果证明了本文方案的有效性。     

并励直流电动机起动过程分析

简述了直流电动机的起动过程及要求,并介绍了并励直流电动机的简化模型及特点.给出了并励直流电动机起动线路常见的两种接法,并对电路中的参数电枢电流和励磁磁通进行了详细的数学推导.结果表明,前一种起动线路中电枢电流和励磁磁通比后一种起动线路中电枢电流和励磁磁通都要大,从而有较大的电磁转矩,有利于并励直流电动机的起动.     

低分压CO_2回收新技术捕集水泥窑气中CO_2的侧线试验

设计了一套水泥窑气CO_2捕集的侧线试验装置,利用自主研发的复合胺溶剂捕集窑气中的CO_2。试验结果表明,新型复合胺溶剂能使净化气中CO_2体积分数降至1.41%以下,产品气中CO_2体积分数达到99%以上。采用该技术,可实现CO_2减排并获得高纯度的CO_2产品气,为企业的CO_2减排提供技术支持。     

Measuring Method for Shunt Resistance of Solar cell

Shunt resistance of solar cell must be monitored for large area solar cell manufactured with conventional process .A measuring method for the shunt resistance is derived from direct-current model.The shunt resistance of solar cell is obtained only by treating a part of Ⅰ-Ⅴdata.     

耦合谐振腔链分路阻抗的测量计算

一、引言耦合谐振腔链的分路阻抗ZT~2是驻波直线加速器设计和制造过程中的重要参量,由它可计算出加速器的能量增益。过去许多资料给出的ZT~2的数值往往是利用一个孤立加速腔测出来的,用此数据计算加速器的能量增益必然给出偏大的结果。这是因为整个谐振腔链的ZT~2不仅与单个谐振腔的几何形状、材料及表面光洁度有关,而且还与整个腔链的调谐     

Compensation characteristics of shunt active and series active power filters

Active power filters have been used in practice to suppress the harmonic interference in power systems. To compensate for harmonic currents of loads, active power filters usually are connected to power systems in parallel with the loads. These filters, which are called shunt active filters here, are very effective for loads that can be considered as current sources, such as thyristor rectifiers with large dc reactances. Many papers have covered the shunt active filters applied to these current-source loads, however, none has discussed characteristics of the shunt active filters when they are applied to voltage-source loads. On the other hand, since more and more diode rectifiers with capacitive dc filters have recently been used, harmonics generated by them have become an issue. The diode rectifier with capacitive dc filters behaves as a voltage source rather than a current source. When a shunt active filter is applied to such a diode rectifier, the current injected from the shunt active filter may flow into the diode rectifier. As a result, harmonics of the source current cannot be reduced effectively, and harmonic current flowing into the diode rectifier increases greatly. This paper presents the aforementioned problem of shunt active filters analytically and experimentally. Then a series active filter is proposed to suppress the harmonic current of the diode rectifiers. The features, operating conditions, and considerations of shunt active filters and series active filters are described analytically and demonstrated experimentally. Taking a diode rectifier with capacitive dc filter as a typical voltage-source load, compensation characteristics of shunt active filters and series active filters are discussed by experiment and simulation. The validity of the series active filters is illustrated experimentally.