An Improved SVG Control Strategy to Suppress Sub-Synchronous Oscillation in Renewable Energy Power System

Inspired by successful efforts for mitigating SSO by adding the auxiliary control strategy on SVG to tackle the SSO issue in large-scale coal-fired power unit, it is still widely conceived for further application in mitigating SSO issue caused by PMSG based wind conversion systems. However, compared to the dedicated SSO mitigation device in coal-fired power unit, the primary objectives of SVG in wind farms are to adjust the fundamental voltage and balance reactive power flow. When the SVG operates at full capacity, the SSO mitigation function cannot work effectively. In an affect to solve this challenge, this paper proposes a modified control strategy of SVG to keep the implementation of subsynchronous damping control (SSDC). Mechanism of the SSDC, as well as the improved control strategy of SVG, was given. The SSDC method and modified SVG strategy was verified by time domain simulation analysis in typical offshore wind farm system. And it is suitable for wide range of additional SSDC methods.