A fast algorithm for the time-domain simulation of switched-mode piecewise-linear systems

An algorithm is presented for the efficient and accurate simulation of switched-mode piecewise-li near systems, a subclass of which includes regulated energy-storage dc-to-dc converters. Three key features of the new algorithm that lead to significant improvements in computational efficiency and accuracy are: (1) a state-transition-matrix table-lookup scheme to solve differential equations describing the system, (2) a modified binary-search strategy to obtain an initial estimate of the instant at which the system topology switches, and (3) a quadratic extrapolation for the accurate final determination of the switching instant. The computational efficiency of a program using the new algorithm is demonstrated by comparing its execution time with that of a program employing a standard fixed-step-size integration algorithm. The accuracy of the new algorithm is verified by comparing results obtained from the simulations with results obtained analytically, and by comparing data from the simulation of two different regulated converters with data measured experimentally.