Hierarchical control applied to a large scale time-delay model of a river

We study the hierarchical control of interconnected systems with time-delays. The classical approach of delay approximation by Taylor series expansion is compared to a new approach consisting of directly injecting the delay terms of the system state equation into the interconnection variables. This provides a reduced order model without any approximation as compared to the first approach. The algorithm of this method is applied to the pollution control of a river and the simulation results are compared to previous works using the first approach on the same example. The efficiency of the approach is clearly shown