随机载荷激励下的风力发电机组首次穿越模型

First-passage model under the excitation of stochastic load of the wind turbine

大型化和轻量化发展后的风力发电系统时变复杂度逐渐增大。同时,风电机组所受载荷具有随机性,导致各组件的长时间振动加剧,进而出现严重损坏,破坏系统的稳定性。通过综合风电机组机械传动模型、确定性载荷模型和随机载荷影响,建立了随机载荷下的首次穿越模型。并结合风电机组的电气动态模型,构建了统一的机电动态模型。采用拟不可积Hamilton随机平均法,建立了相应的Hamilton函数和一维?Ito扩散过程的随机模型,为后续的风力发电机组稳定性和可靠性研究打下基础。以国产某750?k W机组为例建立了相应的统一的机电动态模型,并通过Matlab仿真验证了随机载荷下风力发电机组的首次穿越现象。算例结果表明,该模型具有较好的适用性和可操作性。

With wind turbine system developing larger and lighter, the dimensions of time-varying complexity gradually increase. Meanwhile, the wind turbine loads suffer randomness, which results in stronger prolonged vibration. And then the stability of wind turbine system is seriously damaged. By integrating wind turbine model, deterministic load model and the impact of stochastic load, this paper establishes first-passage model with stochastic load. And combined with the electrical dynamic model of wind turbine, a unified electromechanical dynamic model is built up. By using stochastic averaging method of quasi-non-integrable- Hamiltonian systems, it sets up relevant Hamilton function and the stochastic model of one-dimensional It diffusion process, which will lay a good foundation for following stability and reliability study. With an example of a domestic unit of 750 kW wind turbine, the corresponding unified electromechanical dynamic model is established. And the first-passage phenomenon is verified by a simulation in MATLAB. Simulation results show that the model has good applicability and operability.