Multirate Analysis Method of a Power Electronic Converter by Circuit Partitioning

Various fast and efficient computation techniques for power converter analysis have been researched. According to the conventional methods, a single step size for a whole circuit is selected for the numerical integration. However a power electronic system is multirate where its currents and voltages vary non-uniformly temporally and spatially and its subcircuits have different transient speeds or rates spatially. It is efficient for such a circuit to select an appropriate step size for each subcircuit independently. This technique is called multirate analysis. This paper proposes a new multirate analysis method which divides the whole circuit into subcircuits by applying explicit integration formula to some inductors and capacitors and by applying them with an implicit formula with independent integration step sizes. Finally the method is applied to a DC link inverter control system and the benchmark test circuit proposed by the modeling and simulation committee of SPC in IEEJ. The proposed method is validated for its performances and efficiency by investigating its reduction effects to computational steps and CPU times