Serial control
Thread Content
I have a question: In a single-loop control system, the output of the controller should be the opening degree of the valve, right? What value does the main-loop controller in a cascade control system send to the secondary-loop controller? It should be the difference between the measurement value from the secondary loop and the output of the main loop. So what exactly is the output of the main loop?
The measured value of Circuit 1 (the main circuit) is divided by its range to obtain a percentage; this value is then multiplied by a given ratio, and subsequently multiplied by the range of Circuit 2 (the auxiliary circuit). The resulting value represents the setpoint for Circuit 2, and it is this setpoint that is used to control the control valve.
I finally understand it; thank you so much
This post was last edited by ylb913 on 2016-1-7 at 08:25. It is an example of heating using a heating furnace; the control parameter in this case is the outlet temperature of the material being heated. However, controlling the outlet temperature of the material more quickly and smoothly can be achieved by regulating the flue gas temperature, which is why a cascade control system is used.