Efficient simulation of switched networks using reduced unification matrix

A new and simple formulation method for switched networks in the numerical time domain is presented. Unification models of switching devices, companion models of energy-storage elements, and several straightforward circuit-manipulated operations are used in obtaining a reduced unification matrix (RUM). The feature of the constant formulated RUM is clarified, and the selection of the main parameters of unification models is illustrated. A condition of reducibility is proposed to determine how small the dimensions of a modified nodal matrix (MNM) can be reduced to. Simulation results using the RUM method demonstrate its superiority over the commonly used MNM method, not only for memory requirements, but also for computational speed. A large circuit example shows that the RUM method offers a 76.32% time savings in computation. Additionally, the RUM method possesses the merits of easy formulation, easy programming and more realistic switch modeling, as well as greater accuracy and higher time efficiency when compared with commonly used state-space approaches. These combined advantages should make the proposed RUM method very attractive in the time-domain simulation of switched networks. For large switched networks, the decided advantages are very great.