TY - JOUR
T1 - A novel filter structure to suppress circulating currents based on the sequence of sideband harmonics for high-power interleaved motor-drive systems
AU - Ohn, Sungjae
AU - Jung, Hyun Sam
AU - Boroyevich, Dushan
AU - Sul, Seung Ki
N1 - Publisher Copyright:
© 1986-2012 IEEE.
PY - 2020/1
Y1 - 2020/1
N2 - In this paper, a novel filter structure to suppress circulating currents is proposed based on the sequence of pulsewidth modulation voltage harmonics for high-power interleaved motor-drive systems. The sideband harmonics can be divided into positive-, negative-, and zero-sequence components. Through 120° interleaving among three paralleled inverters, a majority of positive- and negative-sequence harmonics are phase shifted. By these phase shifts, the differential-mode circulating currents between the paralleled ac-dc converters can be suppressed with the proposed filters, which have an identical structure to the three-phase common-mode chokes. Such a structure highly benefits the design and manufacturability for high-power applications where a choice of magnetic-core shapes is limited. Compared to coupled inductors (CIs) with cyclic-cascade or monolithic configurations, the number of magnetic cores can be reduced by one-third. Peak flux-linkages of the proposed filters and the conventional CIs were compared to estimate the size reduction in case of flux-limited designs. Considering the whole modulation index range, which may be required in the motor-drive systems, the maximum flux-linkage can be reduced by 50%. Prototype filters are built and showed a 33% reduction in weight and size compared to the conventional CIs. The validity of the proposed filter is verified through the simulation and a small-scale experiment.
AB - In this paper, a novel filter structure to suppress circulating currents is proposed based on the sequence of pulsewidth modulation voltage harmonics for high-power interleaved motor-drive systems. The sideband harmonics can be divided into positive-, negative-, and zero-sequence components. Through 120° interleaving among three paralleled inverters, a majority of positive- and negative-sequence harmonics are phase shifted. By these phase shifts, the differential-mode circulating currents between the paralleled ac-dc converters can be suppressed with the proposed filters, which have an identical structure to the three-phase common-mode chokes. Such a structure highly benefits the design and manufacturability for high-power applications where a choice of magnetic-core shapes is limited. Compared to coupled inductors (CIs) with cyclic-cascade or monolithic configurations, the number of magnetic cores can be reduced by one-third. Peak flux-linkages of the proposed filters and the conventional CIs were compared to estimate the size reduction in case of flux-limited designs. Considering the whole modulation index range, which may be required in the motor-drive systems, the maximum flux-linkage can be reduced by 50%. Prototype filters are built and showed a 33% reduction in weight and size compared to the conventional CIs. The validity of the proposed filter is verified through the simulation and a small-scale experiment.
KW - Circulating currents
KW - coupled inductors (CIs)
KW - interphase inductors
KW - magnetic integration
KW - parallel three-phase inverters
KW - pulsewidth modulation (PWM)
UR - http://www.scopus.com/inward/record.url?scp=85074188564&partnerID=8YFLogxK
U2 - 10.1109/TPEL.2019.2913329
DO - 10.1109/TPEL.2019.2913329
M3 - Article
AN - SCOPUS:85074188564
SN - 0885-8993
VL - 35
SP - 853
EP - 866
JO - IEEE Transactions on Power Electronics
JF - IEEE Transactions on Power Electronics
IS - 1
M1 - 8698855
ER -