Parameters selection criteria of proportional-integralncontroller for a quadratic buck converter

Jorge Alberto Morales-Saldaña, Rodrigo Loera-Palomo , Elvia Palacios-Hernández
IET Power Electron., 2014, Vol. 7, Iss. 6, pp. 1527-1535 doi: 10.1049/iet-pel.2013.0343 , 2014.


A criteria for selection of parameters of proportional and integral (PI) controller for a DC–DC quadratic buck converter is proposed here. This procedure was developed from a large-signal model of converter in which a multiloop control scheme is added. This scheme has two control loops: an inner current loop, which improves the dynamic behaviour using a single gain, and a conventional PI controller as outer loop, which provides regulation. For the resulting system, the necessary conditions are derived for the existence of equilibrium point and stability in closed-loop. In comparison with the traditional method of loopshaping, which uses small-signal model, analytic expressions are found that simplifies the selection of controller parameters. At the end, the procedure is applied to 28 W quadratic buck regulator prototype and experimental results are given to verify the effectiveness.