Quadratic state-space modeling technique for analysis and simulation of power electronic converters

This paper presents a quadratic state-space modeling technique for analysis of power electronic converters, The methodology is based on using a least- square-error fitting to derive a quadratic state-space representation for e ach topology, together with automatic determination of switching topology, The algorithm integrates the advantages of calculating topology responses a t the circuit level and determining switching instants at the device level. Several key features of the new model that had to significant improvements in computational efficiency include: 1) its simple quadratic polynomial re presentation for the state-transition matrix in solving the differential eq uations describing each topology; 2) its direct and single-step calculation of the switching instants; and 3) its generality in determining valid topo logy without a prior understanding of the switching relationships, Several examples illustrating the generality and simulation speed of the proposed a pproach are presented, The computational efficiency of the new approach is demonstrated by comparing its simulation time with commercial software usin g the stepwise integration algorithm. The accuracy is verified with the exa ct method and available literature.