An integrated design for batch process using optimal average profit control with unfixed terminal time

摘要

Batch processes are flexible to meet the needs of the fluctuated market and have become very important in the modern chemical industry. Two-level control structure is widely adjusted in the operation of batch process. The higher level is the end-point property control and the low level tracks the time-varying reference trajectories designed by the high level. The two-level control structure does not take the dynamics of the low level into consideration in the high level that the low level cannot track the given trajectories perfectly because of model-plant mismatches. Also, this structure does not take the duration of the batch process into consideration which may lead to economic loss in the end. An integrated control structure is proposed in this paper to deal with the drawbacks of two-level structure. Also, different from the traditional objective of the high level, it is a pure economic objective in the integrated control structure using average profit criteria. In order to gain higher economic performance, the predictive horizon is relaxed here to achieve larger feasible region.