无源双端全隔离方案的提出与实现

为彻底消除长线感应威胁并截断可能出现的地线环流,提出了无源双端全隔离方案。基于该方案所研制的新型光电式无源串口隔离器,实现了数据流携电能的归一化高效传送。成对使用时,可使通信线路两端的数据通信设备接口硬件得到均等而有效的保护,且具备自环测试功能。2010年,该隔离器在大庆油田10座变电站三线制RS232通信系统中安装,并经历了强雷雨时段考验。无源双端全隔离方案,适用于工程模式(或称工业模式)下的点对点全双工数据通信系统。

无源双端全隔离方案的技术要点及应用实效

无源双端全隔离方案,是在两端通信设备接口与通信线路之间各串入一只新型无源串口隔离器,从而使两端设备接口得到"均等而有效"的保护。通过电路形式、振荡频率、元器件参数及变压器绕组匝数变比的优化创新,解决了新型隔离器串口窃电的微功耗高效率隔离传输、由单电源形成双极性逻辑电平、以及两端隔离器的通用性和自环状态下的电能平均分配等关键问题。2010年以来,大庆油田处于该隔离器保护之下的90台通信设备的接口从未因雷击损坏,并能方便地进行自环测试。

A Study on an Airgap Control System in a Rotary-Small-Scaled Linear Induction Motor for Railway Vehicles

In general, it is important to operate the; airgap length uniformly for improving the system efficiency independent of the flatness of the reaction plate in a railway propulsion system by a linear induction motor （LIM）. And it is possible to operate the LIM propulsion system efficiently without a change of the LIM capacity through the airgap length control on the sloped rail. So, in this research, the authors introduce an airgap control system to control the airgap length which depends on the flatness of the secondary reaction plate when the LIM is operated, and design a rotary small-scaled LIM and its airgap control system before manufacturing the real system. Then, the authors analyze some characteristics of the LIM （thrust and normal force, input current, efficiency and power factor）, and through the LIM control modeling, the authors finally analyze an effect of the airgap-length control of the LIM by the airgap control system.