电压源型换流器平均模型在风机建模中的应用

Application of voltage source converter average model in wind power modeling

文中介绍了一种可以应用于风机建模的电压源型换流器(Voltage Source Converter,VSC)平均模型。首先对风机并网模型进行介绍,总结了风电系统中VSC模块的工作原理、运行状态以及控制策略。然后利用傅里叶级数推导出VSC详细模型的表达式,对其进行简化后再结合能量守恒原理得到VSC平均模型的数学模型。最后在PSCAD/EMTDC中分别搭建了风机详细模型和平均模型,对比验证了两者在稳态和暂态工况下的响应,并比较了两者的仿真速度和谐波含量。仿真结果表明,文中提出的平均模型能够准确地描述VSC的动态特性,可用于风电系统机电过程的仿真分析,且能极大地提升仿真速度。

This paper presents an average model of voltage source converter(VSC) for wind power modeling.Firstly,the grid-connected model of the wind power is introduced,and the working principle,operating state and control strategy of the VSC module in the wind power system are summarized.Then,Fourier series is used to deduce the expression of VSC detailed model,which is simplified and then combined with the principle of energy conservation to get the mathematical model of VSC average model.Finally,a detailed model and an average model of the wind power were built respectively in PSCAD/EMTDC to compare and verify their responses under steady and transient conditions,as well as compare their simulation speed and harmonic content.Simulation results show that the average model proposed in this paper can accurately describe the dynamic characteristics of VSC,which can be used in the simulation analysis of the electromechanical process of wind power system,and can greatly improve the simulation speed.