SAPF并网LCL滤波器稳定性

LCL filter stability for Grid-connected SAPF

针对并联有源电力滤波器并网接口LCL滤波器存在谐振峰,易使系统发散的问题,利用增加系统阻尼的方式对滤波器进行改进.研究分析有源阻尼方式优于无源阻尼方式,提出电容电流内环反馈、电容电压内环反馈以及电感电流内环反馈三种双闭环控制模型.通过伯德图法、根轨迹法确定系统的稳定性以及稳定范围,并确定最佳增阻尼.研究结果表明:该方法可有效抑制谐振峰,且稳定性好、成本低、效率高.

Aiming at that the harmonic peak exists in grid-connected LCL filter of SAPF, and easy to cause the problem of divergence, this paper improved the filter by using the method of increasing system damping. Firstly, this study discussed the active damping method that is superior the passive damping, then put forward three kinds of double closed loop control methods, which is respectively the capacitor current feedback inner loop, capacitor voltage feedback inner loop and inverter side inductor current feedback loop, and finally, determined the scope of the system stability and stability, and the optimum damping by Bode diagram and root locus methods. The simulation and experiment show that this method can be effective to suppress resonance peak, as well as has good stability, low cost and high efficiency.