Model Predictive Control of Gas Pipeline Networks

Compressor stations in gas transmission systems consume significant amounts of energy. At present, operating policies for these stations in the face of varying demand are established either through off-line steady state optimization or by trial and error employing simulators. It is well known that the disregard for dynamics can lead to severe violations of the operating constraints and that trial and error procedures can only generate feasible but rarely optimal operating policies. In this paper a general on-line optimization scheme for the operation of gas pipeline networks is presented. It is built around the dynamic simulator GANESI. This simulator is used to predict the behavior of the network when it is subject to any operating policy; a successive quadratic programming optimizer is used to compute the optimal of such operating policies. In order to correct the effects generated by modelling errors, demand forecast errors and errors in the initial conditions, the on-line measurements are used in a state estimator and the optimization is carried out over a moving horizon.