A Comparison of Average Model, Sampled-data Model and Multi-frequency Model Based on DC/DC Converters

The widely-used state-space average model based on DC/DC converters loses its accuracy in high frequency domain, which makes it ineffective to predict the stability of some specific systems. In order to solve this problem, several modified models were provided. This paper mainly focuses on two modified models, i.e. the sampled-data model and the multi-frequency model. By comparing them with traditional average model, a unified model structure is proposed to show the key differences of these models. Through this structure, the basic reason for the frequency limitation of average model can be revealed clearly. And the accuracy and possible application sceneries of these models are discussed. Simulation results are presented as verifications.