低通滤波器调节下逆变器的不稳定现象分析

Analysis of the Instability Phenomenon of the Inverter Under the Low-Pass Filter Control

分析了基于低通滤波器调节的光伏逆变器系统的工作原理,通过频闪映射法建立系统的时变离散模型。针对不同数量级的滤波器时间常数,从调制波频率的视角分析了参数变化对系统慢变稳定性的影响,从载波频率的视角分析了参数变化对系统快变稳定性的影响,并借助频闪采样图、时域图、相轨迹图等数值仿真方法验证了这两种不稳定现象。

This paper analyzed the operational principle of the photovoltaic inverter system based on low-pass filter control,and it established the systematic time-varying discrete model by using the stroboscopic mapping method.This research analyzed the influence of the parameter variation on the stability of the slow-scale system from the perspective of modulated wave frequency with special consideration of the filter time constant from different quantities.Moreover,it analyzed the effect of the parameter variation on the stability of the fast-scale system from the perspective of the carrier frequency.This research used many numerical simulation methods,such as the stroboscopic sampling diagram,time-domain diagram,phase trajectory diagram,to verify both phenomena.