基于粒子群算法的逆变器侧电流反馈的LCL滤波器优化设计

Optimal Design of LCL Filter with Inverter-Side Current Feedback Based on Particle Swarm Algorithm

LCL型输出滤波器因其良好的高频谐波衰减特性在并网逆变器中得到广泛应用。但LCL型滤波器的阻抗特性存在谐振峰,容易导致并网逆变器出现控制不稳定。为了有效抑制谐振,引入逆变器侧电流反馈作为有源阻尼,得到反馈控制下LCL滤波并联逆变器的数学模型。由于滤波器参数和控制参数相互耦合,在满足控制性能的同时优化滤波性能变得尤为复杂。本文提出一种基于粒子群算法对滤波器参数和控制参数进行优化的整体设计方法,以主要谐波段输出特性最佳为优化目标,兼顾滤波性能和控制性能。仿真结果验证了该方法的可行性和有效性。

LCL output filter has been widely used in the grid-connected inverter owing to its good high-frequency harmonic attenuation performance.However,the impedance characteristic of the LCL filter has a resonance peak,which tends to cause unstable control of the grid-connected inverter.In order to effectively suppress the resonance,the inverter-side current feedback is introduced as the active damping and the mathematical model of the LCL-filtered inverter under feedback control is obtained.Since the filter parameters and control parameters are coupled to each other,the design for optimizing the filter performance while meeting the demand of control performance becomes particularly complicated.This paper puts forward an overall design method of optimizing the filter parameters and control parameters based on the particle swarm optimization algorithm.The output characteristics of the main harmonics are taken as the optimization goal in the optimal design,with consideration of the filtering performance and control performance.The simulation results verify the feasibility and effectiveness of the proposed method.