• Home|About JOPS|Editorial Board| Ethics Statement|Indexed-in|Contact us|Chinese
Latest Papers more>>
XU Xiangju,ZHU Miao,HOU Chuanchuan,CAI Xu.Comparative Analysis of Impedance Characteristics of Grid-connected Inverter Cluster with Consideration of Closed-loop Control Strategy[J].JOURNAL OF POWER SUPPLY,2019,17(5):96-105
Comparative Analysis of Impedance Characteristics of Grid-connected Inverter Cluster with Consideration of Closed-loop Control Strategy
Received:November 21, 2018  Revised:April 19, 2019
View Full Text  View/Add Comment  Download reader
DOI:10.13234/j.issn.2095-2805.2019.5.96
Keywords:impedance modeling  grid-connected inverter cluster  stability  sub/super synchronous oscillation  closed-loop control
Fund Project:National Natural Science Foundation of the National Key Research and Development Program of China: Stability Analysis and Control of Power System Integrating Renewable Energy Generation Bases Delivered by HVDC Transmissions (No. 2017YFB0902000)
           
AuthorInstitutionEmail
XU Xiangju School of Electronic Information and Electrical Engineering, Shanghai Jiao Tong University, Shanghai , China
ZHU Miao School of Electronic Information and Electrical Engineering, Shanghai Jiao Tong University, Shanghai , China miaozhu@sjtu.edu.cn
HOU Chuanchuan School of Electronic Information and Electrical Engineering, Shanghai Jiao Tong University, Shanghai , China
CAI Xu School of Electronic Information and Electrical Engineering, Shanghai Jiao Tong University, Shanghai , China
Hits: 122
Download times: 78
Abstract:
      The connection of large-scale new energy to power grid, which uses an inverter cluster as interface, has changed the dynamic characteristics of power grid. In addition, the sub/super synchronous oscillations occur frequently, thus restricting the absorption of new energy. To further study the suppression method for this kind of oscillations, the impedance output from a single grid-connected inverter is taken as the smallest modelling unit, and a sequence impedance model of inverter closed-loop system under PI and quasi-PR control strategies is formulated through the introduction of the harmonic linear method. On this basis, the equivalent impedance model with the consideration of multiple inverters in parallel operation is proposed. By comparing the low-frequency dynamic characteristics of impedance output from the inverter cluster under two closed-loop control strategies and the system stability after the connection to the weak gird, it is found that under the same stability margin of inner current loop, the stability margin of the grid-connected system based on quasi-PR control is larger than that based on PI control, thus reducing the risk of sub/super synchronous oscillations. Finally, the simulation models of grid-connected inverter cluster are built in the Matlab/Simulink simulation platform, and the stability and instability phenomena of grid-connected system in different strong/weak grid environments are simulated, which verifies the results of theoretical analysis.
Close