Predictive Control for Reactors - PCR

PCR (Predictive Control for Reactors) is our software solution (composed of module libraries) for model-based predictive control. We have a long experience in this domain and we have provided many studies to our customers during more than 15 years. PCR is usually associated to CAD tools in order to adjust the controller settings and test the control performances through simulation. PCR provides substantial gains in productivity, quality and energy consumption optimization.

Advantages for instrumental users:

PCR overcomes some PID (Proportional Integral Derivative) shortcomings:

  • Significant time delay: in most cases the PID efficiency is limited to a short time delay compared to the system response time. PCR avoids this drawback because the model includes the time delay.
  • Integrative system: level control by PID is too active (frequent and important actuator changes), while the level requires to be kept within a range by smooth changes. Thanks to the CLTR (Closed Loop Time Response) handling, PCR provides smooth changes when level is within the desired range.
  • Split-range: when using a PID controller, the split range principle assumes that dynamics are similar for each action (heating and cooling). Since they are usually quite different (in terms of time constant and time delay) PID provides poor and oscillating results. Relying on two different models, PCR handles correctly each actuator and actions are computed taking into account all actions applied in the past.
  • Feed forward: the effects of measured disturbances are taken into account in predictions
  • PCR is particularly suitable for chemical reactors and other thermal systems
  • CAD availability: easy tuning and testing using simulation
  • Simplified integration since PCR is a library of modular control blocks in C language and in ST (structured text) language.
  • Technical assistance from Sherpa Engineering
  • Most advanced control technology (MBPC - Model Based Predictive Control)

Advantages for manufacturers:

PCR clearly improves processes in all manufacturing industries such as:

  • Highly stable units on system outputs and actuators
  • Reduction of fluctuations of variables such as qualities, temperatures and concentration
  • Production perturbation reduction during control installation (adjustments and off-line testing reduce the time spent on the real process for tuning)
  • PCR has a direct impact on the product quality improvement and the manufacturing process optimization

In the case of the chemistry and pharmacy industries, PCR is used in chemical reactors to control the temperature of the fluid in the reactor: anticipation of the exothermic trend by feed forwarding the reagent flow and predicting the effects of each hot and cold action.

PCR library has been conceived to be integrated in PLC (Programmable Logic Controller) and DCS (Distributed Control System). Our PCR software version has been integrated in the UnityPro and CONCEPT (QUANTUM, MOMENTUM and PREMIUM) environments jointly with Schneider Electric. PCR is currently provided by both Schneider Electric and Sherpa Engineering.