Comparison of DCM operated PWM DC-DC converter modelling methods including the effects of parasitic components on duty ratio constraint

A comparison among several recently published techniques suitable for discontinuous conduction mode (DCM) operated DC-DC converter switching cell modelling is presented. All these techniques consider the effect of parasitic components due to actual components utilized in assembling converter circuits. The paper is also concentrated on two techniques resulting in a switching cell equivalent circuit. The first one provides a small-signal circuit suitable for straightforward frequency-domain analysis. This technique allows for a derivation in a closed form of the four canonical network functions commonly utilized for a s-domain converter analysis. The second one, more recent, provides a large-signal model suitable for predicting time-domain transients and frequency-domain characteristics when the large-signal model is reduced to a small-signal one. This comparison is new and supported by experimental measurements.