Interaction Analysis among PMSG-Based Wind Turbines Based on Self- and En-Stabilizing Functions

Sub-synchronous oscillation is one of the most challenging issues in modern power systems with a high proportion of wind power. Interactions among the wind turbines are key factors causing the oscillations. This paper aims to propose a method to quantify the interactions among N permanent-magnet-synchronous-generator (PMSG)-based wind turbines by transfer functions and analyze the influence of the interactions on the system stability. We derived different terms of the self- and en-stabilizing functions to describe different interactions caused by different wind turbines analytically. Meanwhile, the parameter sensitivity of this method is proposed to analyze the impact of the system and control parameters on the interactions and the system stability. Examples and simulations are given to show the effectiveness of this method.