基于复转矩系数法的双馈风电机组阻尼转矩建模

Modeling of damping torque of doubly fed wind turbine based on complex torque coefficient method

为研究转子侧变流器及其控制系统对双馈风电机组阻尼的影响机理,考虑机械转矩、电磁转矩、暂态电势、转子侧变流器控制、电压控制以及角度偏移等环节,构建小干扰状态下机组动态模型;然后基于复转矩系数法,推导双馈风电机组阻尼转矩和同步转矩表达式,得到阻尼转矩与机组振荡频率、风速、机组机械参数、电气参数及控制系统参数有关,转子侧变流器内环、外环控制参数之间相互耦合,共同影响机组的阻尼;最后,通过仿真对所建数学模型进行验证。仿真验证结果表明:在不同振荡频率下,所建模型均具有适用性。

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.