Model order reduction of hyperbolic systems using method of characteristics and differential transform

Convection dominated systems described by first order hyperbolic PDE models are common in chemical engineering. Use of such PDEs in model based control requires a large number of states for its representation and consequently requires significant computational effort. Recently, Sudhakar et al. (2013a, b) have proposed to use method of characteristics (MOC) to obtain reduced order models for such systems and have demonstrated its use in model based control. The implementation of MOC requires the use of repeated solution of initial and boundary value problem. In this work we propose to use differential transform technique to obtain approximate analytical solution for these problems, which result in significant reduction in computational effort. The technique is demonstrated in two case studies involving fixed bed reactor and plug flow reactor. The comparison of dynamic response and the computational load from using DT and numerical integration of the resulting differential equations indicates the effectiveness of using DT in MOC. © IFAC.