Impedance Measurement in Dynamic Analysis of Multi-Converter Systems
Tran, Minh (2021)
2021
Master's Programme in Electrical Engineering
Informaatioteknologian ja viestinnän tiedekunta - Faculty of Information Technology and Communication Sciences
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Hyväksymispäivämäärä
2021-08-10
Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi:tuni-202107096273
https://urn.fi/URN:NBN:fi:tuni-202107096273
Tiivistelmä
Advancements in power electronics have led to the growing number of applications of
DC distribution multi-converter systems in recent years. The dynamics and stability
of multi-converter systems can be conveniently analyzed using methods based on the
evaluation of DC network bus impedances. Therefore, efficient and fast wideband
methods for measuring the frequency-responses of converter impedances as part of the
bus impedance calculation are needed. The pseudo-random binary sequences (PRBS)
are highly suitable broadband excitations for converter impedance identification due
to many attractive properties such as easy generation, controllable frequency-domain
parameters and low measurement time. The thesis work reviews the broadband
methods for frequency-response measurements of a multi-converter network using
PRBS, and provides studies of DC distribution systems and their stability analysis
methods. A simulation approach and a practical experiments are presented in the
work to verify the reviewed measurement techniques. The benefits of using binary
excitations in power converter impedance estimation were successfully verified. In
addition, some of the limitations and special considerations with the methods were
briefly discussed. These limitations included the PRBS’s amplitude design tradeoff
and its sensitivity to environment noise disturbances.
DC distribution multi-converter systems in recent years. The dynamics and stability
of multi-converter systems can be conveniently analyzed using methods based on the
evaluation of DC network bus impedances. Therefore, efficient and fast wideband
methods for measuring the frequency-responses of converter impedances as part of the
bus impedance calculation are needed. The pseudo-random binary sequences (PRBS)
are highly suitable broadband excitations for converter impedance identification due
to many attractive properties such as easy generation, controllable frequency-domain
parameters and low measurement time. The thesis work reviews the broadband
methods for frequency-response measurements of a multi-converter network using
PRBS, and provides studies of DC distribution systems and their stability analysis
methods. A simulation approach and a practical experiments are presented in the
work to verify the reviewed measurement techniques. The benefits of using binary
excitations in power converter impedance estimation were successfully verified. In
addition, some of the limitations and special considerations with the methods were
briefly discussed. These limitations included the PRBS’s amplitude design tradeoff
and its sensitivity to environment noise disturbances.