AVERAGING LEVEL CONTROL FOR SURGE TANKS IN SERIES

摘要

Optimal averaging level control for single surge tanks is fairly well developed. However, the extension of single-tank strategies to networks of tanks, without the requirement to resort to full-blown multivariable control and numerical optimization, is still an open problem. In this report, we propose a novel control strategy for systems composed of multiple surge tanks arranged in series (also known as a cascade). The proposed strategy is near optimal in that it minimizes the maximum rate of change of the outlet flow (MRCO) from the system while keeping all the levels within constraints. It does not require the use of numerical optimization and, therefore, is easily implemented. Simulations of a two-tank system are used to compare the performance of the proposed strategy to the optimal multivariable control strategy, and a decentralized control strategy composed of independent single-tank optimal averaging level controllers.