PLC检测柴油机转速的设计

Detecting the Diesel Speed by Using PLC

早期采用PLC设计柴油机的安全保护回路时,直接采用三线制转速传感器的脉冲信号经过处理后输出;后来应船级社要求,转速传感器回路需要增加断线检测功能,于是使用PLC配合光耦板来检测三线制转速传感器的回路是否正常并采集转速信号,但在应用中发现存在应急启动柴油机后没有运行信号的漏洞;最后研发了采用PLC、两线制转速传感器以及断线监测模块这三者配合起来检测转速传感器的回路是否正常并完成柴油机转速信号采集的功能。每一次在功能上都有升级,但升级的同时也会带来其他问题,针对实际使用时出现的问题进行分析、研究,并提出一种新的解决方案。

Early stage,when used PLC to design the diesel engine safety protection circuit,it used the three-wire signal of speed sensor directly and made some treatment,then outputted. Later,to satisfy the requirement of the classification society,the speed sensor safety protection circuit should own the disconnection detection function,so used PLC and optocouple plate to detect if the three-wire speed sensor circuit is normal and collect the speed signal,but ofter putted into use,it existed the loop hole that there was no operation signal when the diesel started in emergency mode. Finally, developed a method combine PLC, two-wire speed sensor and wire break supervision module the three part to detect if the speed sensor safety protection circuit was normal as well as collect the engine speed signal. Every time the detection method change could make the promotion of function,but the promotion also brought other problems,this essay aims at the problem occurred in actual usage,makes analyzation and research,and presents a new solution.