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Robust stability analysis of active voltage control for high-power IGBT switching by Kharitonov's theorem

Accepted version
Peer-reviewed

Type

Article

Change log

Authors

Yang, X 
Yuan, Y 
Long, Z 
Mendes Silva Goncalves, Jorge  ORCID logo  https://orcid.org/0000-0002-5228-6165
Palmer, PR 

Abstract

The main idea of active voltage control (AVC) is to employ classic feedback-control methods forcing the IGBT collector voltage transient to follow a predefined trajectory. This feedback control of IGBTs has great advantages in guaranteeing that IGBTs remain in safe operating area (SOA), restricting EMI, mitigating the voltage/current stress, minimizing/predicting their power losses, and balancing voltages of IGBTs in series. Inevitably, however, AVC introduces stability issues. Based on the assumption that accurate IGBT small-signal model parameters are available, an analogue proportional-derivative and multiloop feedback control was proposed to achieve stable performance in previous work. Due to nonlinearities and uncertainties in IGBT parameters, previous stability analysis methods have important limitations. This work uses Kharitonov's theorem during the IGBT controlled turn-off to assess the system's stability and guide the AVC design to account for model uncertainties and varying parameters. We conducted experiments to investigate the system's robust stability due to these uncertainties in the IGBT parameters, which confirm the validity of the proposed theoretical analysis. With the use of wide bandwidth op-amps, it is shown that the feedback design may be simplified.

Description

Keywords

insulated gate bipolar transistors, automatic voltage control, switches, stability criteria

Journal Title

IEEE Transactions on Power Electronics

Conference Name

Journal ISSN

0885-8993
1941-0107

Volume Title

31

Publisher

IEEE
Sponsorship
Engineering and Physical Sciences Research Council (EP/I03210X/1)
Engineering and Physical Sciences Research Council (EP/L021579/1)