Electric valve is one of the important control components in the industrial control field of papermaking, petrochemical, power station and refrigeration.
The type of electric valve can be divided into non-opening feedback, only two points (full open, full off) state feedback and continuous opening feedback. Valves with continuous opening feedback are the ideal pursuit for valve manufacturers and debuggers. However, for the same type of valves, valves with continuous opening feedback are much more expensive than non-opening feedback and only Two-point status feedback valve. Therefore, it is necessary to make software compensation for the valve without continuous opening degree, so that it has continuous opening feedback.
The opening control of the electric valve uses a stepping PID controller (incremental) FB42, which calculates the error value of the set value and the measured value to obtain the increased or decreased value of the valve position, and then outputs the pulse. The signal is then driven by the signal to rotate forward or reverse to achieve the purpose of controlling the valve. The controller does not require any output signal when the valve is to be held in a position.
Therefore, the valve manufacturer should combine the characteristics of the electric valve to master the continuous opening degree control and opening calculation method without the continuous opening feedback valve, improve the control precision of the valve, and make the electric valve meet the requirements of various industrial occasions.