This article reports on feedback control algorithms for thermal systems modeled via the network approach. These networks belong to the class of descriptor systems. They are subject to nondecaying disturbances and, therefore, integral action is required for zero offset. The article includes the derivation of optimal integral controllers for general linear descriptor systems and a detailed study on decentralized control for thermal networks. Feasibility of decentralized control is established via two theorems regarding stability and decentralized integral controllability of thermal networks. Additionally, a particular strategy for the synthesis of decentralized controllers is proposed. This article concludes with a sample of the numerical tests that we performed to demonstrate the efficiency of the proposed algorithms.

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