TY - JOUR
T1 - Small-signal converter admittance in the pn-frame
T2 - systematic derivation and analysis of the cross-coupling terms
AU - Amico, Gabriele
AU - Egea Àlvarez, Agustí
AU - Brogan, Paul
AU - Zhang, Shuo
N1 - © 2019 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.
PY - 2019/12/31
Y1 - 2019/12/31
N2 - A methodology is presented to derive the small-signal admittance of a converter based control system in the pn-frame. Such a methodology makes use of a set of derived equations which link the qd-frame small-signal admittance data to the corresponding pn-frame small-signal admittance terms. Compared to existing results providing the pn-frame small-signal impedance of a grid connected converter, the presented technique allows a calculation of the pn-frame small-signal admittance (or impedance) when additional elements are present in the controller, as in many practical designs. The presented technique is therefore generic and provides a systematic way to calculate the pn-frame admittance regardless of the used converter control scheme. In the study, the method has been applied to assess how different parts of the controller affect the pn-frame admittance terms and, in particular, the cross-coupling which exists between its positive and negative sequence terms. Thereby, the results of the proposed methodology have been used to study the impact of the negative sequence current compensator on the stability performance of a grid-connected converter. Experimental tests using a real hardware set up are used to support the obtained results.
AB - A methodology is presented to derive the small-signal admittance of a converter based control system in the pn-frame. Such a methodology makes use of a set of derived equations which link the qd-frame small-signal admittance data to the corresponding pn-frame small-signal admittance terms. Compared to existing results providing the pn-frame small-signal impedance of a grid connected converter, the presented technique allows a calculation of the pn-frame small-signal admittance (or impedance) when additional elements are present in the controller, as in many practical designs. The presented technique is therefore generic and provides a systematic way to calculate the pn-frame admittance regardless of the used converter control scheme. In the study, the method has been applied to assess how different parts of the controller affect the pn-frame admittance terms and, in particular, the cross-coupling which exists between its positive and negative sequence terms. Thereby, the results of the proposed methodology have been used to study the impact of the negative sequence current compensator on the stability performance of a grid-connected converter. Experimental tests using a real hardware set up are used to support the obtained results.
KW - voltage source converter
KW - mirror frequency effect
KW - dual vector current control
KW - impedance-based stability criterion
U2 - 10.1109/TEC.2019.2924922
DO - 10.1109/TEC.2019.2924922
M3 - Article
SN - 0885-8969
VL - 34
SP - 1829
EP - 1838
JO - IEEE Transactions on Energy Conversion
JF - IEEE Transactions on Energy Conversion
IS - 4
ER -