PLC实现自动重合闸设计.doc

摘 要 据统计，系统中永久性故障一般不到10%，其余故障都是由于雷击过电压引起的绝缘子表面闪络，大风时的短时碰线，树枝落在导线上等引起的瞬时故障。当系统出现故障时，保护立刻动作使线路或设备断电，在非常短暂的时间内，故障点的电弧就会自动熄灭，使绝缘自动恢复。此时自动重合闸装置动作，自动将断路器合上，恢复系统正常运行。 针对传统的电磁式重合闸装置存在动作级数多，触点粘连等不可靠因素，采用PLC实现自动重合闸，对其进行硬件设计和软件编程，所用元件极少，故障率大大降低，克服了电磁式重合闸控制方式的不足。控制柔性好，控制系统的供电可靠性高。分析了传统继电器式自动重合闸装置存在的缺点，提出利用PLC设计自动重合闸装置，绘出梯形图。 关键词：可编程逻辑控制器（PLC），自动重合闸，可靠性，应用 Abstract According to statistics, permanent fault in the system generally less than 10 per cent and the rest were due to failures caused by lightning over-voltage insulator surface flashover, when the winds of short-term touch lines, tree branches fell from the upper wire transient fault. When the system failure, immediate action to protect the power lines or equipment, in a very short time, the point of failure will automatically extinguish the ARD, is insulated to resume. At this point automatically reclosing device moves automatically close the circuit breaker and restore normal operation system. Aiming at the unreliable factors that the traditional electromagnetic ARD device has more actiongrades and adhering of contact, using PLC to realize the auto-reclosure andmaking the design for hardware and soft-ware, the used components is fewer, accident chance ismuch lower. The method overcomes the defects of the traditional electromagnetic ARD control method. So control flexibility is strong and the reliability of power-supply of control system is high. The artica Analyses the defects in traditional relay automatic reclosing, proposes application of PLC in the design automatic relcosing and draws a ladder chart. Keywords: pragramable logic controller(PLC),auto-reclosure,reliability,application  目 录 摘 要 I Abstract II 1 绪 论 1 2 自动重合闸 2 2.1 自动重合闸的定义 2 2.2 自动重合闸的基本概念 2 2.2.1 自动重合闸的作用 3 2.2.2 自动重合闸的要求 3 2.2.3 自动重合闸的选择原则 3 2.2.4 自动重合闸的启动方式 4 2.3 自动重合闸的构成和原理 4 2.3.1 正常情况 5 2.3.2 故障情况 6 2.3.3 手动跳闸 6 2.3.4 手动合闸 6 3 可编程控制器 7 3.1 PLC的特点 7 3.2 PLC的基本结构 10 3.3 PLC的工作原理 12 4 PLC控制自动重合闸 13 4.1 PLC自动重合闸系统概述 13 4.2 自动重合闸的选择 15 4.3 PLC的选型与设计