Centralised solution for subsynchronous control interaction of doubly fed induction generators using voltage-sourced converter

• Published in: IET generation, transmission & distribution Vol. 9; no. 16; pp. 2751 - 2759
• Main Authors: Wang, Liang, Xie, Xiaorong, Jiang, Qirong, Liu, Xiangdong
• Format: Journal Article
• Language: English
• Published: The Institution of Engineering and Technology 03.12.2015
• Subjects: asynchronous generators; centralised control; centralised SSCI mitigation scheme; control system synthesis; controller design; damping; demonstrated eigenvalue analysis; doubly fed induction generators; eigenvalues and eigenfunctions; electrical resonance power; equivalent circuits; equivalent electric circuit; fixed series compensated transmission lines; power convertors; power generation control; power system stability; power transmission lines; SSD; stabilisation; subsynchronous control interaction; subsynchronous damper; subsynchronous instability; subsynchronous resonance; sufficient conditions; time‐domain analysis; time‐domain simulation; voltage sourced converter; wind farms; wind power plants; power transmission lines; equivalent electric circuit; centralised control; controller design; demonstrated eigenvalue analysis; power generation control; equivalent circuits; subsynchronous instability; eigenvalues and eigenfunctions; sufficient conditions; centralised SSCI mitigation scheme; electrical resonance power; doubly fed induction generators; wind power plants; power system stability; power convertors; voltage sourced converter; SSD; fixed series compensated transmission lines; asynchronous generators; time-domain analysis; control system synthesis; damping; subsynchronous control interaction; wind farms; subsynchronous resonance; stabilisation; time-domain simulation; subsynchronous damper
• ISSN: 1751-8687; 1751-8695; 1751-8695
• DOI: 10.1049/iet-gtd.2015.0720

Practical subsynchronous instability events have been observed in doubly fed induction generator-based wind farms, which are radially connected to fixed series compensated transmission lines. As a special type of subsynchronous resonance, this phenomenon is described here as subsynchronous control interaction (SSCI). This study proposes a centralised SSCI mitigation scheme named as subsynchronous damper (SSD). In this scheme, an additional high-power electronic voltage-sourced converter is added to the collection bus of wind farms. It is designed to dissipate the electrical resonance power of SSCI. Thus, SSD provides positive damping for SSCI. Its basic principle is explained with equivalent electric circuit and the sufficient conditions for stabilisation are obtained mathematically. Controller design guidelines are given and have been verified first by eigenvalue analysis. Then a method to choose the capacity of power electronic converter is proposed. The effectiveness of SSD is finally demonstrated by extensive time-domain simulations on a target system.