基于分数阶LCL滤波器的风力发电网侧控制研究

RESEARCH ON GRID-SIDE CONTROL OF WIND POWER GENERATION BASED ON FRACTIONAL LCL FILTER

为提高并网电能质量,提出采用分数阶PI(PI^(λ))控制器来实现网侧控制、采用分数阶LCL(FOLCL)滤波器进行滤波的方案。首先通过理论推导得出FOLCL滤波器能从根本上避免谐振的特性,然后建立网侧逆变系统分数阶数学模型,并推导分数阶双闭环控制结构,最后在网侧引入PI^(λ)控制器并对其参数进行设计。仿真实验结果表明:FOLCL滤波器可从根本上避免谐振;所设计的FOLCL滤波器效果明显优于传统的整数阶LCL(IOLCL)滤波器;所建全分数阶逆变并网系统各项指标均明显优于传统方案。

With the popularization and application of wind power technology,improving the quality of wind power grid-connected power is of great significance to the stability of the power system.In order to improve the quality of grid-connected power,this paper proposes the use of a fractional-order PI(fractional-order PI,PI^(λ))controller to achieve grid-side control,and a fractional-order LCL(fractionalorder LCL,FOLCL)filter for filtering.Firstly,it is deduced by mathematical theory theory that FOLCL filter can fundamentally avoid the characteristic of resonance.Then a fractional-order mathematical model of the grid-side inverter system is established,and a fractional-order double closed-loop control structure is derived.Finally,the PI^(λ)controller is introduced on the grid side and its parameters are designed.The experimental simulation results show that of the FOLCL filter can effectively avoid resonance.The effect o the FOLCL filter designed in this paper is significantly better than that of the traditional integer-order LCL(IOLCL)filter.All indicators of the full fractional-step inverter grid-connected system built in this paper are significantly better than that of the traditional schemes.