Oscillation Energy based Sub-synchronous Oscillation Analysis for Wind Farm

Sub-synchronous Oscillation (SSO) is a serious incident in power system, and has been occurred in wind farms many times during the past decade. In this paper, energy flow method is used to analysis the SSO interactions. Firstly, the relationship between oscillation energy and damping is explained. Then, the oscillation function between two nodes in a power system is presented. By calculating the SSO energy from the measureable signals, the SSO energy flows between different nodes in the power system can be revealed. Simulation shows how different wind turbine generators interact, and discusses the relationship between SSO energy flow and equivalent resistance of wind turbine generator.