We show the main results obtained when applying the average theory to Zero Average Dynamic control technique in a buck power converter with pulse‐width modulation (PWM). In particular, we have obtained the bound values for output error and sliding surface. The PWM with centered and lateral pulse configurations were analyzed. The analytical results have confirmed the numerical and experimental results already obtained in previous publications. Moreover, through an important lemma, we have generalized the theory for any stable second‐order system with relative degree 2, using properties related to transformations and stability of linear systems.