TY - JOUR
T1 - DQ-Frame Impedance Measurement of Three-Phase Converters Using Time-Domain MIMO Parametric Identification
AU - Gong, Hong
AU - Wang, Xiongfei
AU - Yang, Dongsheng
PY - 2021/2
Y1 - 2021/2
N2 - The dq-frame impedance model is increasingly employed to analyze the grid-converter interactions in three-phase systems. As the impedance model is derived at a specific operating point, it is required to connect the converter to actual power grids during the impedance measurement. Yet, the nonzero grid impedance causes cross-couplings between perturbation and response signals, which consequently jeopardize the accuracy of impedance measurement. This article analyzes first the coupling effect of the grid impedance on the measured impedance, and then proposes a multiple-input multiple-output parametric impedance identification method for mitigating the effect. Instead of using the fast Fourier transform, the method allows for obtaining the parametric impedance model directly from the time-domain data. Further, with the simultaneous wideband excitations, only a single measurement cycle is needed. The effectiveness of the method is verified in both simulations and experimental tests.
AB - The dq-frame impedance model is increasingly employed to analyze the grid-converter interactions in three-phase systems. As the impedance model is derived at a specific operating point, it is required to connect the converter to actual power grids during the impedance measurement. Yet, the nonzero grid impedance causes cross-couplings between perturbation and response signals, which consequently jeopardize the accuracy of impedance measurement. This article analyzes first the coupling effect of the grid impedance on the measured impedance, and then proposes a multiple-input multiple-output parametric impedance identification method for mitigating the effect. Instead of using the fast Fourier transform, the method allows for obtaining the parametric impedance model directly from the time-domain data. Further, with the simultaneous wideband excitations, only a single measurement cycle is needed. The effectiveness of the method is verified in both simulations and experimental tests.
KW - Coupling effect
KW - impedance measurement
KW - multiple-input multiple-output (MIMO) parametric identification small-signal model
UR - http://www.scopus.com/inward/record.url?scp=85092563335&partnerID=8YFLogxK
U2 - 10.1109/TPEL.2020.3007852
DO - 10.1109/TPEL.2020.3007852
M3 - Journal article
SN - 0885-8993
VL - 36
SP - 2131
EP - 2142
JO - IEEE Transactions on Power Electronics
JF - IEEE Transactions on Power Electronics
IS - 2
M1 - 9137400
ER -