[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.
自从二十世纪八十年代中期,计算机监控系统在水电厂开始应用以来,它在水电厂应用越来越广泛。新建电厂大多数都采用计算机监控系统与新机组同步投运,绝大多数没有采用监控系统的老水电厂已经或正在进行以计算机监控系统为中心的综合自动化改造。计算机监控系统是水电厂创国内一流水电厂基础,更是创国际一流水电厂,实现“无人值班,关门运行"的前提条件。
随着计算机监控系统在国内水电厂应用不断扩大,计算机监控系统的结构也在不断地变化发展。近一二十年,计算机按照摩尔定律迅速发展,对监控系统结构的发展影响很大。论文作者从事计算机监控系统的现地控制单元(以下简称LCU)研制工作,愿意将近来LCU结构变化趋势与大家共同分析探讨,希望同行专家能多提宝贵意见。
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