基于谐振积分器的有源阻尼法

摘要

With the increasing application of LCL filter in grid connected inverter,the resonance problem of LCL filter can not be ignored.Through analysis,the higher feedback coefficient can get a higher resonance suppression ability in the traditional capacitor current feedback.Because the resonant integrator has a frequency selective characteristic,the resonant frequency component of the capacitive current can be extracted and it still has a good ability to suppress resonance at low feedback coefficient through analysis.The control method with combining resonant integrator and active damping method of capacitor current feedback is adopt to guarantee the stability of the system.The simulation and experimental results verify the correctness and efficiency of the scheme.%随着LCL滤波器在并网逆变器中广泛应用,LCL滤波器存在的谐振问题不容忽视.传统电容电流反馈中反馈系数越高,谐振抑制能力越强,但会导致系统不稳定.由于谐振积分器具有特有的频率选择性,可根据此特性提取出电容电流中谐振频率分量,在低反馈系数时仍拥有很好的谐振抑制能力.故可采用谐振积分器与电容电流反馈的有源阻尼法相结合的控制方法来保证系统稳定性.仿真与实验验证了其正确性与高效性.