Stability Analysis of Grid-Connected VSC Based on Impedance Modelling

• Published in: 8th Renewable Power Generation Conference (RPG 2019) p. 220
• Main Authors: Liang Yuan, Ke Meng, Jingjie Huang, Yilun Sun, Dong, Z.Y
• Format: Conference Proceeding
• Language: English
• Published: Stevenage, UK IET 2019; The Institution of Engineering & Technology
• Subjects: Control of electric power systems; Converters; d.c. transmission; Eigenvalues; Impedance; Modelling; Permanent magnets; Polar coordinates; Power convertors and power supplies to apparatus; Power system control; Stability analysis; Synchronous machines; Time domain analysis; Wind power; Wind power plants; different modelling method; HVDC power convertors; sequence domain impedance; stability analysis; impedance methods; power generation control; polar coordinates impedance; eigenvalues and eigenfunctions; HVDC power transmission; subsynchronous oscillation issues; synchronous generators; detailed VSC model; power grids; wind power plants; power system stability; power convertors; impedance model; permanent magnet generators; time-domain analysis; permanent magnet synchronous generator based wind farm; emerging impedance modelling; SSO issues; eigenvalue analysis method; dq domain impedance; grid-connected voltage-sourced converters; grid-connected VSC; time domain simulation; frequency scan method
• ISBN: 9781839531255; 1839531258
• DOI: 10.1049/cp.2019.0475

Recently, real field incidents have shown that permanent magnet synchronous generator (PMSG) based wind farm are prone to subsynchronous oscillation (SSO) issues when integrated into weak AC systems. The mechanism behind this subsynchronous interaction (SSI) is still unclear, and great concern has been aroused to the stability of grid-connected voltage-sourced converters (VSC) both in academia and industry. The main approaches to analysing the SSO issues include the frequency scan method, eigenvalue analysis method, time domain simulation and impedance modelling method. Depending on the domain that impedance model derived from, existing literature of impedance modelling can be classified into three categories, namely sequence domain impedance, dq domain impedance, and polar coordinates impedance. This paper focuses on the emerging impedance modelling and aims to provide a comprehensive understanding of different modelling method. Detailed derivation of these three impedance methods is presented. Through the stability analysis of VSC, the pros and cons of different methods are compared. Finally, A detailed VSC model is built in the RTDS to validate the results.