Frequency response power function of PWM DC/DC converter. Part I

Frequency response characterization is a principal tool for sensitivity analysis an open loop and closed loop stable system. The small signal average and classical sampled-data models are suitable ways of measuring the sensitivity of a converter system at low frequencies. However they are not a suitable means of characterizing a system when there is significant amplitude of ripple exist in the system output and also the validity of the model is limited to the half of sampling frequency. In this paper after an introduction to the notion of frequency response of lifted system, we will introduce the idea of frequency response power function for the lime lifted system. Frequency response power function will provide an extended mean to characterize a system with large ripples. Later we will develop the expressions for estimating the frequency response power function of an open and closed loop converter system. Several examples have been given to demonstrate the advantages of present notion of frequency response power function