Performance Improvement of Grid-Connected DFIG based Wind Energy Conversion System in Subsynchronous Operation using Adaptive Control

Abstract

This study proposes a adaptive controller for the reduce the subsynchronous resonance (SSR) for grid-connected DFIG based wind energy conversion system considering the small signal effect of rotor side converter (RSC) and grid side converter (GSC). For analysis of SSR considering different operating conditions such as varying wind speed and compensation level, a unique mathematical model of DFIG based windfarms presents in state space model. The model includes subsystems such as wind turbine, DFIG, series compensated grid connected line and novel Rotor Side Converter RSC-GSC model. The time domain analysis for SSR and and the effective SSR damping control technique is built in MATLAB/SIMULINK. This technique avoids the addition of extra SSR Damping Controller (SSRDC) and use an efficient Fuzzy Logic Controller (FLC) based single controller for RSC. This controller is an effective dual-purpose controller and is utilizes for power control of the WECs as well as for damping the torque due to SSR. Simulation results shows in dynamic condition electromagnetic torque oscillation reduces significantly compares to conventional control. The FLC posses high disturbance rejection capabily.