Application of Robust Regulator in Crystallization Process

Crystallization is an important method to purify substances. It is widely applied in pharmacy and chemical industries. Penicillin crystallization is a complicated process with time-variable, uncertain and multivariable. The requirement of control in different stage is variable and there are some coupling between temperature and liquid level control in the tank. Traditional PID control is difficult to attain better control effect. In response to this complex project, this paper proposed the robust control methods. First the coupled of system was eliminate by series decoupling compensator. Then disturbance regulator was designed, which aimed to ensure robustness. Finally compensator was designed by state-feedback, which aimed to ensure stability and better dynamic performance. The simulation results show that precision control, robustness and stability of the system are enhanced. The robust control can get better effect in the crystallization process control.