LCL型有源电力滤波器并网电流控制研究

摘要

Out -put current and DC voltage are the key factors of APF control. L and LC type grid - connected current contain more harmonic current around switching frequency, owing to the switching frequency limitation, besides, larger filtering inductance will make the equipment bigger, cost higher, and influence the grid control dynamic performance. However, the LCL filters can achieve better performance. So the analysis of PI controller stability, the inner - inductance current tracking characteristics , grid - connected current tracking characteristics and grid voltage suppression characteristics in dead zone for LCL type filters are researched in this paper, then concludes the requirements of grid index on the closed - loop root frequency.%APF的控制关键就是对输出电流及直流侧电压进行控制,L,LC型并网的并网电流由于开关频率受限,并网电流含有较大的开关频率附近的谐波电流,同时滤波电感过大导致设备体积大,成本高,并影响并网控制的动态性能.LCL型滤波器有着更好的效果,该文就LCL型滤波器PI控制的稳定性,内电感电流跟踪特性,并网电流跟踪特性和电网电压抑制特性进行了深入研究,得出了并网指标对闭环根频率的技术要求.