The intelligent control system of the heavy-duty SCR rectifier

In chemical industry, there are many use of the heavy-duty silicon-controlled-rectifier to produce caustic soda and the technique of producing caustic soda by ion exchange membrane (IEM) is a new technique with many advantages. After analyzing the electric feature of IEM load in detail, the author proposes a nonlinear mathematical model for the electricity loop of the IEM equipment and rectifier, deduces the intelligent PID control algorithm, designs a intelligent diagnosis system for the operation disturbance of IEM equipment. In the system, the system identification method is used to identify the mathematics model of the load consisting of rectifier and ion-film caustic soda production-line; the experience knowledge base and intelligent inference are used to judge the working states of rectifier and to control the rectifier through the nonlinear PID controller. The system has been successfully used in several factories and the results has been much improved compared to common control systems