In order to study the influence mechanism of rotor-side converter and its control system on damping characteristics of doubly-fed wind turbine

a dynamic model of the wind turbine under small disturbance state is constructed considering mechanical torque

electromagnetic torque

transient potential

rotor-side converter control

voltage control and angle offset. Then

the damping torque and synchronous torque expressions of the doubly-fed wind turbine are derived based on the complex torque coefficient method. The damping torque is related to the oscillation frequency

wind speed

mechanical parameters

electrical parameters and control system parameters of the wind turbine

and the control parameters of the inner and outer loops of the rotor-side converter are coupled with each other to affect the damping of the wind turbine. Finally

the mathematical model is verified by time domain simulation and frequency domain simulation. The results show that the model has applicability at different oscillation frequencies.