High-frequency extension of the small-signal model of the constant-frequency current-mode-controlled converter

By introducing a simple high-frequency extension function (HFEF), it is possible to significantly improve the accuracy of the averaged small-signal dynamical model of the current-mode-controlled converter. The high-frequency extension function is an approximate description of the actual processes in the converter, and is therefore physically well-founded. The method is generally accurate, and easy to use. The author summarizes the physical background of the method, briefly discusses the general HFEF, discusses how to incorporate the HFEF into the converter model (including the characteristic coefficients, the block-schematic representation, and the various transfer functions of the power cell), and gives a practical frequency-domain and time-domain example (both predictions and test data), for the application of the HFEF, including a subharmonic stability analysis of the feedback-regulated converter