用PLC改造高压电机二次回路的研究

Transform the twice return circuit of high pressure electrical machinary with PLC

二次回路在高压电机的运行中 ,起着开、停、保护设备的作用 ,因此 ,它需要有及高的可靠性 .在需要启动时 ,如满足条件 ,应能立即启动 ;在需要跳闸时 ,应能立即从电网中切除高压电机 ,并显示出跳闸原因 .但现有的继电器控制的二次回路由于继电器固有的缺陷 ,不能满足人们对其高性能的要求 .对现有高压电机二次回路的不足之处进行了分析 ,提出了用可编程控制器实现原有功能的方法 ,对其进行了选型 ,绘制了梯形图 .改造后的二次回路可靠性大大提高 。

Twice return circuit has the function of starting, stopping and protecting the equipment,it should be very reliable.When condition is satisfied,it must start at once.When needed,it should stop the high pressure electrical machinery from the electrical net and indicate the causes.Due to the defect of the relay,twice return circuit controlled by relay can not meet the requirements of its excellent function.It has analyzed the deficiency of the available twice return circuit of high pressure electrical machinery,put forward the approach of performing its original functions in PLC,choosen the type and provided the trapezoid drawings.