基于LADRC与模糊自适应的新型有源阻尼谐振抑制策略

New Active Damping Resonant Suppression Strategy Based on Linear Active Disturbance Rejection and Fuzzy Adaptive

针对LCL型并网逆变器固有谐振属性容易引起系统谐振,影响系统稳定性的问题,采用无需增添额外传感器的并网电流反馈有源阻尼(GCFAD)法抑制谐振,并引入高通滤波器(HPF)抑制传统GCFAD中二次微分环节对高频谐波电流的放大效应。为应对电网阻抗变化导致谐振频率偏移时阻尼参数难以根据系统变化进行实时调节,提出一种基于线性自抗扰的新型并网电流反馈模糊自适应有源阻尼控制策略(FHPF-LADRC),进一步提高系统的鲁棒性。使用频域分析法分析新型有源阻尼控制对抑制系统谐振峰值和高频谐波衰减的效果,通过仿真结果验证了新型有源阻尼控制策略不仅有效提高系统阻尼效果,还增强系统稳定性和谐波抑制力,具有较好的可行性。

The inherent resonance of grid-connected inverter with LCL filter is apt to cause system resonance,affecting the system stability.In the paper,the grid-connected current feedback active damping(GCFAD)method without additional sensors is used to suppress resonance,and high pass filter(HPF)is introduced to suppress the amplification of high-frequency harmonic current by second derivative.It is difficult to adjust damping parameters in real time according to system changes when resonance frequency offsets due to grid impedance variation,so an active damping control strategy of new grid current feedback based on linear active disturbance rejection and fuzzy adaptive is proposed to further improve the robustness of the system.Effects of the new active damping control on resonant peak and high frequency harmonic attenuation are analyzed by frequency domain analysis method.The simulation results show that the new active damping control strategy has great feasibility because it not only effectively improves the damping effect of the system,but also enhances the system stability and harmonic suppression force.