Generic circuit partitioning method for efficient simulation of modular multilevel converter topologies

A generic circuit partitioning method is proposed which reorders the equations and variables of power electronic circuits with idealized switches and diodes in a specific bordered block-triangular form, where each block on the diagonal is dependent only on a small number of switches. The number of floating-point operations for sparse matrix triangularization, needed after a change of switch configuration, is reduced significantly by using the possibility to individually store the triangular LU factors of the diagonal blocks in memory for each possible switch configuration. The method is applicable to any power electronic circuit, but is especially beneficial for electromagnetic transient simulation involving modular multilevel converter (MMC) HVDC topologies where the number of switching components is usually very large.