Analysis of SSR characteristics in DFIGs based wind farm integrated to a series-compensated network

Abstract

To improve transmission capacity and stability margin of the power system, the doubly fed induction generators (DFIGs) based wind farm is transmitted over lines equipped with series compensation (fixed capacitors). However, the utilisation of series compensation brings the potential risk of subsynchronous resonance (SSR) in the power system. In this study, the SSR issue in DFIGs based wind farm integrated to a series-compensated network is studied based on the eigenvalue analysis and equivalent impedance model. The linearised state-space model of DFIGs based wind farm integrated to a series-compensated network is built first. Participation factors, sensitivities of eigenvalues and root loci, obtained by linearised state-space model, are observed to investigate the mechanism and the key parameters of SSR. Then, a method that can mitigate SSR in DFIGs based wind farm integrated to a series-compensated network is proposed based on virtual series resistance of the rotor. At last, the eigenvalue analysis and simulation are conducted to verify the effectiveness of the proposed mitigation method.

Keywords

• wind power plants
• asynchronous generators
• subsynchronous resonance
• rotors
• eigenvalues and eigenfunctions
• state-space methods
• eigenvalue analysis
• dfigs based wind farm
• series-compensated network
• power system
• series compensation
• ssr
• linearised state-space model
• virtual series resistance
• transmission capacity
• equivalent impedance model
• rotor
• doubly fed induction generators