新型改进锁相环FBD电流检测方法的实现

摘要

传统的谐波检测方法中,在电网电压畸变和频率偏移时,锁相环系统锁相不准确,影响谐波检测精度.在Fryze算法(FBD法)的基础上,提出利用改进的陷波器(LPN)锁相环(PLL)方法,该方法对两路线电压进行处理,再通过陷波器滤出畸变电压中的零序、负序分量和高次谐波,得到与基波正序电压同频同相的三相参考电压信号.理论推导和仿真结果表明,所提出的改进方法能有效地改善电网电压畸变时谐波电流的检测精度.%In the traditional harmonic detection method,phase lock loop is not accurate when the grid voltage distortion and frequency deviation,which affects the precision of harmonic detection.Making use of LPN and PLL based on FBD,the voltage of two line is processed and the zero-sequence,negative sequence components and higher-order harmonics of distorted voltage based on trapper are filtered,so the three-phase reference voltage signal with the same phase as positive sequence voltage of fundamental harmonic can be obtained.Theory and simulation indicate the method can improve the detection precision of harmonic current effectively when the grid voltage is distorted.