Parameters selection criteria of proportional–integral controller for a quadratic buck converter

• Published in: IET power electronics 2014-06, Vol.7 (6), p.1527-1535
• Main Authors: Morales-Saldaña, Jorge Alberto, Loera-Palomo, Rodrigo, Palacios-Hernández, Elvia
• Format: Article
• Language: English
• Subjects: closed loop systems; closed‐loop system; DC‐DC power convertors; DC‐DC quadratic buck converter; electric current control; inner current loop; loopshaping method; multiloop control scheme; parameters selection criteria; PI control; PI controller; power 28 W; proportional–integral controller; quadratic buck converter; stability
• ISSN: 1755-4535; 1755-4543; 1755-4543
• DOI: 10.1049/iet-pel.2013.0343

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.