Active voltage balancing in flying capacitor multi-level converters with valley current detection and constant effective duty cycle control

Andrew Stillwell, Enver Candan, Robert C.N. Pilawa-Podgurski

Research output: Contribution to journalArticle

Abstract

One of the challenges of utilizing flying capacitor multi-level (FCML) converters is the flying capacitor balancing. Poorly balanced flying capacitors increase the switch voltage stress, which is detrimental to performance and device rating requirements. Previously, valley current detection was shown as a potential method to balance flying capacitors, but the method suffers from poor flying capacitor balancing performance at light load. Here, we investigate the light load conditions that lead to poor balancing and propose a new method, constant effective duty cycle (CEDC) compensation, which provides active balancing for the full load range of the converter. The proposed method is validated with a 4-level FCML experimental prototype, demonstrating excellent flying capacitor balancing over all load ranges, across the full duty cycles range and with multiple induced flying capacitor imbalances.

Original languageEnglish (US)
Article number8664674
Pages (from-to)11429-11441
Number of pages13
JournalIEEE Transactions on Power Electronics
Volume34
Issue number11
DOIs
StatePublished - Nov 2019

Fingerprint

Capacitors
Electric potential
Switches

Keywords

  • Active balancing
  • DC-DC
  • flying capacitor
  • flying capacitor multilevel (FCML)
  • GaN
  • multilevel
  • valley current detection

ASJC Scopus subject areas

  • Electrical and Electronic Engineering

Cite this

Active voltage balancing in flying capacitor multi-level converters with valley current detection and constant effective duty cycle control. / Stillwell, Andrew; Candan, Enver; Pilawa-Podgurski, Robert C.N.

In: IEEE Transactions on Power Electronics, Vol. 34, No. 11, 8664674, 11.2019, p. 11429-11441.

Research output: Contribution to journalArticle

@article{2bab4d2bf4b44729a743d5aeaeefd5ed,
title = "Active voltage balancing in flying capacitor multi-level converters with valley current detection and constant effective duty cycle control",
abstract = "One of the challenges of utilizing flying capacitor multi-level (FCML) converters is the flying capacitor balancing. Poorly balanced flying capacitors increase the switch voltage stress, which is detrimental to performance and device rating requirements. Previously, valley current detection was shown as a potential method to balance flying capacitors, but the method suffers from poor flying capacitor balancing performance at light load. Here, we investigate the light load conditions that lead to poor balancing and propose a new method, constant effective duty cycle (CEDC) compensation, which provides active balancing for the full load range of the converter. The proposed method is validated with a 4-level FCML experimental prototype, demonstrating excellent flying capacitor balancing over all load ranges, across the full duty cycles range and with multiple induced flying capacitor imbalances.",
keywords = "Active balancing, DC-DC, flying capacitor, flying capacitor multilevel (FCML), GaN, multilevel, valley current detection",
author = "Andrew Stillwell and Enver Candan and Pilawa-Podgurski, {Robert C.N.}",
year = "2019",
month = "11",
doi = "10.1109/TPEL.2019.2899899",
language = "English (US)",
volume = "34",
pages = "11429--11441",
journal = "IEEE Transactions on Power Electronics",
issn = "0885-8993",
publisher = "Institute of Electrical and Electronics Engineers Inc.",
number = "11",

}

TY - JOUR

T1 - Active voltage balancing in flying capacitor multi-level converters with valley current detection and constant effective duty cycle control

AU - Stillwell, Andrew

AU - Candan, Enver

AU - Pilawa-Podgurski, Robert C.N.

PY - 2019/11

Y1 - 2019/11

N2 - One of the challenges of utilizing flying capacitor multi-level (FCML) converters is the flying capacitor balancing. Poorly balanced flying capacitors increase the switch voltage stress, which is detrimental to performance and device rating requirements. Previously, valley current detection was shown as a potential method to balance flying capacitors, but the method suffers from poor flying capacitor balancing performance at light load. Here, we investigate the light load conditions that lead to poor balancing and propose a new method, constant effective duty cycle (CEDC) compensation, which provides active balancing for the full load range of the converter. The proposed method is validated with a 4-level FCML experimental prototype, demonstrating excellent flying capacitor balancing over all load ranges, across the full duty cycles range and with multiple induced flying capacitor imbalances.

AB - One of the challenges of utilizing flying capacitor multi-level (FCML) converters is the flying capacitor balancing. Poorly balanced flying capacitors increase the switch voltage stress, which is detrimental to performance and device rating requirements. Previously, valley current detection was shown as a potential method to balance flying capacitors, but the method suffers from poor flying capacitor balancing performance at light load. Here, we investigate the light load conditions that lead to poor balancing and propose a new method, constant effective duty cycle (CEDC) compensation, which provides active balancing for the full load range of the converter. The proposed method is validated with a 4-level FCML experimental prototype, demonstrating excellent flying capacitor balancing over all load ranges, across the full duty cycles range and with multiple induced flying capacitor imbalances.

KW - Active balancing

KW - DC-DC

KW - flying capacitor

KW - flying capacitor multilevel (FCML)

KW - GaN

KW - multilevel

KW - valley current detection

UR - http://www.scopus.com/inward/record.url?scp=85070220012&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85070220012&partnerID=8YFLogxK

U2 - 10.1109/TPEL.2019.2899899

DO - 10.1109/TPEL.2019.2899899

M3 - Article

AN - SCOPUS:85070220012

VL - 34

SP - 11429

EP - 11441

JO - IEEE Transactions on Power Electronics

JF - IEEE Transactions on Power Electronics

SN - 0885-8993

IS - 11

M1 - 8664674

ER -