Active Control of Drive Chain Torsional Vibration for DFIG-Based Wind Turbine

Due to the fast electric control of the doubly-fed induction generator (DFIG) when experiencing power grid disturbance or turbulent wind, the flexible drive chain of the wind turbine (WT) generates long-term torsional vibration, which shortens the service life of the drive chain. The torsional vibration causes fatigue damage of the gearbox and affects power generation. In this paper, a two-channel active damping control measure is proposed. The strategy forms a new WT electromagnetic torque reference value through two channels: one is a proportion integration differentiation (PID) damping term with frequency difference, which is used to reduce torsional vibration caused by frequency difference between fan and shafting; the other adopts the torsional vibration angle (θs) as the feedback signal, and an additional damping term is formed by bandpass filter (BPF) and trap filter (BRF). The strategy can increase the electromagnetic torque and suppress the torsional vibration of the drive chain. Finally, modeling and simulation using MATLAB/Simulink show that the method can effectively suppress the torsional vibration of the drive chain without affecting power generation.