*Article* **Distributed Model Predictive Control of Steam**/**Water Loop in Large Scale Ships**

**Shiquan Zhao 1,2,3,\*, Anca Maxim 1,3,4, Sheng Liu 2, Robin De Keyser 1,3 and Clara M. Ionescu 1,3,5**


Received: 12 June 2019; Accepted: 5 July 2019; Published: 11 July 2019

**Abstract:** In modern steam power plants, the ever-increasing complexity requires great reliability and flexibility of the control system. Hence, in this paper, the feasibility of a distributed model predictive control (DiMPC) strategy with an extended prediction self-adaptive control (EPSAC) framework is studied, in which the multiple controllers allow each sub-loop to have its own requirement flexibility. Meanwhile, the model predictive control can guarantee a good performance for the system with constraints. The performance is compared against a decentralized model predictive control (DeMPC) and a centralized model predictive control (CMPC). In order to improve the computing speed, a multiple objective model predictive control (MOMPC) is proposed. For the stability of the control system, the convergence of the DiMPC is discussed. Simulation tests are performed on the five different sub-loops of steam/water loop. The results indicate that the DiMPC may achieve similar performance as CMPC while outperforming the DeMPC method.

**Keywords:** distributed model predictive control; steam power plant; steam/water loop; multi-input and multi-output system; loop design
