Analysis of the effect of phaselocked loop on input admittance of converter station in flexible DC transmission system

Authors

Peifa LI, School of Electrical and Information Engineering, Changsha University of Science and Technology, Changsha 410114 , China；State Grid ZhejiangXiangshan Power Supply Company, Xiangshan 315700 ,China
Xin TANG, School of Electrical and Information Engineering, Changsha University of Science and Technology, Changsha 410114 , China
Wen WANG, School of Electrical and Information Engineering, Changsha University of Science and Technology, Changsha 410114 , China
Tian LI, School of Electrical and Information Engineering, Changsha University of Science and Technology, Changsha 410114 , China；State Grid ZhejiangXiangshan Power Supply Company, Xiangshan 315700 ,China

Keywords

admittance matrix, phaselocked loop, small signal analysis, impedance model

Abstract

The accuracy of the impedance model of the converter station directly affects the small interference stability analysis of the flexible DC transmission system. However, the more accurate the model, the higher the order, which increases the complexity of the analysis. To analyze the influence of the phaselocked loop on the impedance characteristics of the converter station, we firstly establish the admittance matrix of the AC side of the converter station under the two conditions of dq coordinates with and without consideration of the phaselocked loop, and then establish the same order and mirror admittance of the converter station at the static coordinates. By comparing and not considering the input admittance of the phaselocked loop, it is concluded that the influence of the phaselocked loop on the input admittance value is directly related to the cutoff frequency of the phaselocked loop transfer function. Finally, the simulation model is established in PSCAD software. We use the signal injection method to obtain the homologous and mirror admittance of the converter station to verify the correctness of the theoretical analysis.

DOI

10.19781/j.issn.16739140.2020.04.003

First Page

20

Last Page

26

Recommended Citation

LI, Peifa; TANG, Xin; WANG, Wen; and LI, Tian (2020) "Analysis of the effect of phaselocked loop on input admittance of converter station in flexible DC transmission system," Journal of Electric Power Science and Technology: Vol. 35: Iss. 4, Article 3.
DOI: 10.19781/j.issn.16739140.2020.04.003
Available at: https://jepst.researchcommons.org/journal/vol35/iss4/3