A method for improving the speed of simulation of switched-mode power supply circuits

The authors describe work carried out to improve the simulation speed of an un-isolated Cuk switching power-supply. A simulation model was written using APEX, which is a circuit description language compatible with SPICE but with added features, and DIABLO, a simulation language employing `C´ type structures and which integrates with APEX. A technique known as state-averaging has been used to derive the defining equations of a number of switching-power-supply topologies. State-averaging involves representing the transfer function of a converter as an equation involving no switching, but incorporating δ, the duty cycle