This paper proposes a technique to track and regulate the “true average” current in any branch of a pulse-width modulated dc-dc power converter. An example buck converter in continuous-conduction mode is considered. A comprehensive characterization is presented for the proposed scheme. An overall dc and small-signal analysis of the inner current loop is performed. The current average current-mode control methods suffer from switching instability at low duty ratios due to a large ripple in the sensed current. Moreover, the current error amplifier's high-frequency pole located at the switching frequency neither alleviates the stability issue nor improves the dynamic response of the converter. In the proposed approach, a low-pass filter, which attenuates any high-frequency ripple is placed in the feedback path of the current loop. Consequently, the control voltage is nearly dc and proportional to the actual average value of the inductor current. The inner current loop gain transfer function of the presented circuit has been derived. The following critical path closed-loop transfer functions have been derived: reference voltage-to-inductor current and reference voltage-to-output voltage. Using practical specifications of a buck dc-dc converter, a theoretical framework to design the inner loop is presented. Verification of the theoretically predicted transfer functions and transient analysis is performed through simulations.

Average current-mode control of buck DC-DC converter with reduced control voltage ripple / Saini, Dalvir K.; Reatti, Alberto; Kazimierczuk, Marian K.. - ELETTRONICO. - (2016), pp. 3270-3275. (Intervento presentato al convegno 42nd Conference of the Industrial Electronics Society, IECON 2016 tenutosi a Palazzo dei Congressi, ita nel 2016) [10.1109/IECON.2016.7793204].

Average current-mode control of buck DC-DC converter with reduced control voltage ripple

REATTI, ALBERTO;
2016

Abstract

This paper proposes a technique to track and regulate the “true average” current in any branch of a pulse-width modulated dc-dc power converter. An example buck converter in continuous-conduction mode is considered. A comprehensive characterization is presented for the proposed scheme. An overall dc and small-signal analysis of the inner current loop is performed. The current average current-mode control methods suffer from switching instability at low duty ratios due to a large ripple in the sensed current. Moreover, the current error amplifier's high-frequency pole located at the switching frequency neither alleviates the stability issue nor improves the dynamic response of the converter. In the proposed approach, a low-pass filter, which attenuates any high-frequency ripple is placed in the feedback path of the current loop. Consequently, the control voltage is nearly dc and proportional to the actual average value of the inductor current. The inner current loop gain transfer function of the presented circuit has been derived. The following critical path closed-loop transfer functions have been derived: reference voltage-to-inductor current and reference voltage-to-output voltage. Using practical specifications of a buck dc-dc converter, a theoretical framework to design the inner loop is presented. Verification of the theoretically predicted transfer functions and transient analysis is performed through simulations.
2016
IECON Proceedings (Industrial Electronics Conference)
42nd Conference of the Industrial Electronics Society, IECON 2016
Palazzo dei Congressi, ita
2016
Saini, Dalvir K.; Reatti, Alberto; Kazimierczuk, Marian K.
File in questo prodotto:
File Dimensione Formato  
Average_Buck.pdf

accesso aperto

Tipologia: Pdf editoriale (Version of record)
Licenza: Tutti i diritti riservati
Dimensione 2.06 MB
Formato Adobe PDF
2.06 MB Adobe PDF

I documenti in FLORE sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificatore per citare o creare un link a questa risorsa: https://hdl.handle.net/2158/1078229
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 20
  • ???jsp.display-item.citation.isi??? 11
social impact