Improvement and application of the degital PID regulator in heavy-medium density control at Tengqing Coal Washery

The density control system used at Tengqing Coal Nashery suffers from the drawbacks of being low in stability and anti-interferense capability. For tackling this problem,renovation is made of the existing control system through taking the following measures: introduction of derivation control for higher stability of the control system; introduction of integral separation and anti-integral saturation methods for guarding against excessive over-regulation,long-time fluctuation and overflow of actuating mechanism;incomplete improvement of differential terms for higher anti-interference capability; and introduction of dead zone control for avoiding frequent fluctuation of system. The renovated control system proves to be high in system regulation speed,working stability and control accuracy,well meeting the requirement of field operation.