(A) general switching-function-based state-space modeling of switching power systems

Abstract

A new and generalized modeling of switching power systems is developed. The modeling makes it possible to represent such systems with only one state equation. The state equation is transformed to the Fourier state equation which is believed to be a useful analysis technique for ac converters as well as dc converters. The modeling also unifies several existing modelings such as state-space average modeling, existence-function-based modeling, switched-resistor-based modeling, and topology-based modeling. Time-varying and non-linear nature of switching systems is explicitly described by the proposed modeling. New concepts such as the state source and the virtual source are introduced for systematic and unified description of switching systems. Application examples are shown for a boost converter, a series resonant converter and a three-phase current source inverter. And the Fourier state equation of the three-phase current source inverter is simulated. Thus the trend of the solutions of the Fourier state equation is illustrated and state-space average modeling is shown to be unfit for ac converter modelings.