摘要
对动态电压恢复器电压跌落检测方法中的单相软件锁相环进行了研究,针对基于求导法的αβ-dq变换单相锁相环检测精度易受到电网电压中低频分量的影响,在此基础上提出了基于形态滤波的单相软件锁相环。设计了形态滤波器,根据滤波后信号的特点选取了适当的结构元素和形态变换算法,以此来抑制锁相环鉴相器输出中的2次谐波,提高锁相环的检测精度。最后对两种方法进行仿真对比实验,结果表明该方法能够大幅度削弱鉴相器输出中的2次谐波,且延时小,锁相环可以准确、快速锁定相位。
The soft PLL( Phase Locked Loop used in the voltage sag of dynamic voltage restorer is studied. To avoidthe impact of the low frequency component of Grid voltage in Dynamic Voltage Restorer voltage drop method basded on the derivation of αβ-dqtransformation,a soft PLL based on the mathematical morphology filter is presented,which selects the appropriatemorphologic structure elements and the proper morphologic operators to design a low-passmorphological filter for restraining the second harmonic produced by the phase detector output andimproving the detection accuracy of PLL. Finally,simultation experiment result of two methods show that,the interference is substantially attenuated and the operation of morphological filter issimple and fast,meeting the requirements of PLL detection.
出处
《自动化与仪器仪表》
2016年第1期53-55,共3页
Automation & Instrumentation
基金
兰州工业学院青年科技创新项目(13K-011)
