Steady State Analysis of Switching Converters without Predefined Switching Period

Abstract

The use of steady-state analysis offers the advantage of finding the switching converter steady state without requiring the simulation of its transient phase providing savings in both computation time and computer memory usage. Different techniques for quickly obtaining the steady state of a switching converter have been proposed in the past such as the shooting method. Two things these techniques share in common are the requirements that the converter's switching frequency remain constant during the whole mode of operation and that there be prior knowledge of this switching frequency before starting the simulation process. The proposed steady state analysis techniques, which require the prior knowledge of the switching frequency, are unable to properly obtain the steady state solution. One example of a circuit functioning with a variable switching frequency over time is a switching converter based on hysteresis current control mode. The use of a constant switching period can no longer be justified for the steady-state analysis of such a circuit. In this paper, we propose a novel steady state analysis technique, which is capable of quickly finding the steady state solution of a power converter controlled without any predefined switching frequency. Preliminary simulation results are presented showing the validity of this new steady-state analysis approach.