Adaptive Average Current-Mode Control of a Buck Converter Supplying Plasma Arc Loads
Abstract
Reliable operation of plasma processes requires a power supply that can regulate and limit the arc current despite rapid changes of the electrical load. Gas-flow fluctuations, arc motion, changing attachment conditions, and electrode interactions can cause abrupt arc-voltage variations and may lead to arc interruption. The power supply must therefore provide fast current control and a suitable actuation layer for supervisory stabilization. This paper presents an adaptive average current-mode controller for a buck converter supplying a nonlinear plasma arc load. Based on an averaged model of the converter inductor dynamics, the controller combines current-error feedback with feedforward compensation of the measured arc voltage. Online adaptation of the inductance and its effective series resistance compensates for converter-parameter uncertainty without requiring an online nonlinear arc model. A Lyapunov analysis establishes bounded estimation errors and asymptotic current tracking for the averaged closed-loop system under bounded-reference assumptions. Experiments with an argon plasma arc demonstrate contact-opening ignition and current-reference tracking under varying arc- voltage conditions, supporting the controller as a fast current-control layer for plasma applications.
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BibTeX
@misc{ecker2026adaptive,
title = {{Adaptive Average Current-Mode Control of a Buck Converter Supplying Plasma Arc Loads}},
author = {Lukas Ecker and Thomas Voglhuber-Brunnmaier},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.07930},
eprint = {2610.07930},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.07930},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Adaptive Average Current-Mode Control of a Buck Converter Supplying Plasma Arc Loads
AU - Lukas Ecker
AU - Thomas Voglhuber-Brunnmaier
PY - 2026
DA - 2026/10/06
PB - arXiv
DO - 10.48550/arxiv.2610.07930
UR - https://arxiv.org/abs/2610.07930
AB - Reliable operation of plasma processes requires a power supply that can regulate and limit the arc current despite rapid changes of the electrical load. Gas-flow fluctuations, arc motion, changing attachment conditions, and electrode interactions can cause abrupt arc-voltage variations and may lead to arc interruption. The power supply must therefore provide fast current control and a suitable actuation layer for supervisory stabilization. This paper presents an adaptive average current-mode controller for a buck converter supplying a nonlinear plasma arc load. Based on an averaged model of the converter inductor dynamics, the controller combines current-error feedback with feedforward compensation of the measured arc voltage. Online adaptation of the inductance and its effective series resistance compensates for converter-parameter uncertainty without requiring an online nonlinear arc model. A Lyapunov analysis establishes bounded estimation errors and asymptotic current tracking for the averaged closed-loop system under bounded-reference assumptions. Experiments with an argon plasma arc demonstrate contact-opening ignition and current-reference tracking under varying arc- voltage conditions, supporting the controller as a fast current-control layer for plasma applications.
ER -