王熙凤是个好领导

PLC直接上网结构智能设备接入方式探讨 - 接入 方式 探讨 设备 智能 直接 上网 结构 PLC LCU 通讯

刘 晓 波

（中国水利水电科学研究院 自动化研究所 100038）

[摘要]本文简述了国内水电厂计算机监控系统变化发展历史和变化过程，对计算机监控系统现地控制单元的结构发展方向进行了探讨。重点探讨了近几年开始应用PLC直接上网LCU结构及其特点，主要讨论了在该种模式下智能设备接入的方式、速率、可靠性、编程的复杂性、可接入设备的数量等方面的特点。本文通过比较分析的方法对这些问题作了比较详细的探讨，并得到下面结论：（1）PLC直接上网的LCU结构优于经过工控机上网LCU结构；（2）智能设备以直接接入PLC现地总线方式最好；（3）智能设备经串口转换接入PLC或经串口直接上网方式，具有普遍应用意义；（4）智能设备直接上网是很有前途的方式。本文也讨论了在PLC直接上网模式下，如何实现CPU、输入、输出、电源和机箱联接电缆等冗余策略，为大型、特大型水电厂实现无人值班的目标，提供了可借鉴的方法。

关键词：水电厂 无人值班 计算机监控系统 现地控制单元 结构

Research on Structure Development of Local Control Uints of Computerized Supervision and Control System

Liu Xiaobo

（Department of Automation，IWHR 100038 ）

Abstract：This paper reviews the development history and process of local control units of Computerized Supervision and control system，researches the development direction of LCU structure ,focuses its attention on the structure of LCU

structure of PLC linking to local area net directly and its characteristics． It compares different methods of intellective devices linking to LCU in their modes, speed, stability, program complexity and the number of linking

intellective devices. After discussion, the author gets results: (1) the

structure of PLC linking to LAN is better than the structure of IPC linking to LAN. (2) the mode of intellective devices joints LCU through PLC field bus is better. (3) intellective devices joints LCU through PLC serial ports or

intellective devices joints to LAN through PLC serial ports may apply in every PLC. (4) the mode of intellective devices joints to LAN directly will be

promising in the future .It discusses the redundancy strategy on how to realize input ，output，power，CPU in the mode new structure．This helps huge and cadreman hydropower plants to realize the target of no-man on duty.

Keywords: Hydropower plant, No-man on duty, Computerized Supervision and control system, Local control units, Structure.