基于LCL滤波的PWM整流器稳定性控制的研究

摘要

LCL filter is widely applied in three-phase PWM rectifier with its excellent performance in high order harmonic attenuation.There are two current feedback modes while choosing grid voltage orientated to the reference frame with voltage and current double loops as system's control scheme.The system's stability under two different feedback current modes is compared and the results show that the system has better stability while using inductance current on power grid,so it can avoid complicated passive or active damping algorithm. LCL filter with higher resonance frequency shows better inhibiting effect on low-order harmonics. Finally the experimental results are provided to validate the theoretical analysis on the 350 kW experimental platform.%LCL滤波器在滤除高次谐波上的优越性,使其在三相PWM整流器中得到广泛应用.当系统采用电网电压定向的电压电流双闭环控制策略时,反馈电流的方式有反馈PWM整流器交流侧电感电流和反馈电网侧电感电流两种.这里重点分析比较了两种不同反馈方式对系统稳定性的影响,结果表明采用反馈网侧电流控制时,系统稳定性较好,可省去复杂的无源或有源阻尼算法而适当提高谐振频率,增强对低次谐波的抑制.最后,在350 kW实验平台上,通过实验验证了理论分析的正确性.