对在用电梯控制系统方面的改造
摘 要
用可编程控制器（PC）实现对电梯的逻辑控制，实质上是使控制算法不再由硬件逻辑所固定，而是通过程序储存器中的程序（软件）进行控制。因此，对于有不同功能要求的电梯控制系统，只要改变程序储存器中的程序指令——软件即可，而无需变更或减少硬件系统的布线。因而十分便于使用、管理和改变功能要求。另一方面也减少了控制系统体积，减低能耗和减低维修保养费用。本文使用三菱可编程逻辑控制器代替传统的继电器-接触器控制系统，编制在用电梯控制所需要的全部程序，确定了PC的输入输出信号。
关键词：电梯控制，可编程控制器，软件逻辑
Reconstruction of On-Service Elevator Controlling System
ABSTRACT
Using Programmable Controller to realize the logical controlling of elevators is virtually making the controlling arithmetic not to be decided by hardware logic, instead, by programs stored in program memory (software). Therefore, as for different functional requirement of elevator controlling system, we just need to change the instructions stored in memory, needless to change or diminish the installation of hardware system. So it’s very convenient to use, manage and change the instructions. To another hand, it has diminished the volume of the controlling system, reduced energy consumption and expense to maintenance. In this article, we use Mitsubishi Programmable Logic Controller to replace traditional relay – contactor controlling system, compile all the programs needed for elevator controlling, and set up the input/output ports of PC.
Key Words: elevator controlling, PC, software logic
目 录
中文摘要 ABSTRACT
第一章 绪 论······························································1
1.2 第二章 2.1 第三章第四章
电梯的电气控制系统···············································1 电梯电气系统的分类···············································1 电梯电气控制的基本原理··············································3 电梯运行的条件··················································3
2.2 电梯的工作状态··················································3 2.3 电梯控制线路的主要组成··········································3 2.4 电梯运行的速度曲线··············································5
可编程控制器（PC）控制系统··········································6
3.1 PC的定义和特点··················································6 3.2 PC的基本工作原理················································7 3.3 PC的基本结构····················································8 3.4 三菱FX2系列PC中使用的各种元件·································9
可编程控制器在电梯控制系统上的应用·································16
4.1开关门控制电路··················································18 4.2层楼控制和显示电路··············································21 4.3自动和检修定向电路··············································23 4.4启动、加速控制电路··············································27 4.5减速停车和自动平层控制电路······································29 4.6指令和召唤信号的的登记和消除电路································33 4.7检修运行控制电路················································36 4.8指令专用和超载控制··············································37
1.1
第一章 绪 论
1.1 电梯的电气自动控制系统
根据不同的用途，电梯可以有不同的载荷，不同的速度及不同的驱动和控制方式。即使相同用途的电梯，也可采用不同的操纵控制方式。但电梯不论使用何种控制方式，总是按轿厢内指令，层站的召唤信号要求，向上或者向下启动、运行、减速、制动、停站。
为了实现电梯电气控制，过去大多是采用继电器逻辑线路，这种硬布线的逻辑控制方式具有原理简单，直观的特点。但是通用性差，对不同的层楼和不同的控制方式，其原理图、接线图等必须重新绘制，且逻辑系统由多个触点组成，接线复杂，故障率高。因此，目前逐渐被可靠性高、通用性强的可编程控制器及微机处理器所代替。
用微机实现继电器的逻辑功能，比继电器控制有较大的灵活性，不同的控制方式可以用相同的硬件，只是软件不同。只要把按钮，限位开关、光电开关、无触点行程开关等元件做为输入信号，而把制动器、接触器等功率输出元件接到输出端，就算完成了全部接线任务。一般，功能、层数变化，无需增减继电器和大量的线路。 1.2 电梯电气系统的分类
（一）继电器—接触器控制系统
这种控制系统是过去国内许多电梯厂家广泛使用的一种电梯电气控制系统。该系统与其他系统相比，结构比较简单，易于理解和掌握。但从使用观点看，该系统有以下缺点：
1．接点易磨损，电接触不好； 2．接点闭合缓慢；
3．体积大，控制屏（柜）占机房面积大； 4．控制系统的能量消耗大； 5．维修保养工作量大、费用高。
由于该系统有上述诸多弊病，因此继电器—控制器系统仅仅用于电梯速度不高(V≤2.5m/s)和要求不十分高的场合。
（二）半导体逻辑控制系统
随着本世纪60年代开始半导体技术及其器件的发展和广泛应用，由晶体三极管、二极管等电子器件替代了继电器—接触器的有触点系统。这种控制技术避免了上述继电器—接触器系统存在的缺点。从其可靠性来说可谓是“半永久性”的，因其没有接点的磨损或接触不良的问题，也即不存在接点的使用“寿命”问题。
但是该系统是以所谓“硬件”逻辑运算为基础的，即根据控制算法和要求进行布线，而各控制元件的布线必须单独进行。以后若需对原定的控制要求（算法）有更改时，往往就必须改变布线。
（三）微机控制系统
- 1 -