On accuracy of averaged control-to-output frequency responses of switched DC-DC converters

The control-to-output (CTO) frequency response of switched DC-DC converter describes how the small-signal harmonic perturbation of the converter switching duty ratio influences the converter output. In the paper, the CTO frequency response obtained by the method of harmonic balance is compared with the CTO response, obtained by applying the well-known State-Space-Averaging (SSA) technique to switched converters. These comparisons are made for the Buck-, Boost-, and Buck-Boost- type converters. Conclusions about the accuracy of the SSA method are drawn within the context of the character of the state matrices of the converter.