雷电冲击电压波形K因子零相位数字滤波器设计

针对最新版IEC60060-1《高电压试验技术,第一部分:一般定义及试验要求》中叠加过冲和振荡的标准雷电冲击波形的数字处理程序,其引入与频率相关的试验电压因数k(f),介绍一种设计等价于k(f)对应转移函数的K因子零相位IIR数字滤波器的方法。对零相位数字滤波原理进行了分析与仿真实验。基于IEC60060-1中定义的试验电压因数k(f),给出了设计K因子零相位IIR数字滤波器的推导过程,以及可用于开发冲击电压测量软件的时域滤波差分方程。最后对最新版IEC61083-2《高压冲击试验测量用仪器和软件,第二部分:对软件的要求》附带的TDG 2.04中几种典型雷电冲击电压波形进行了滤波处理与参数提取,验证了该方法的可行性和准确性。为研制冲击电压测量系统提供了一种实用的数字滤波技术。

Design of zero-phase digital filter with K factor used in parameters evaluation for lightning impulse

According to the procedures for calculation of parameters of standard lightning impulses with superimposed overshoot or oscillations in IEC 60060-1 Ed.3.0: High-voltage test techniques Part 1: General definitions and test requirements,and the introduced frequency dependent test voltage factor k(f),a way to design of zero-phase digital filter corresponding to the k(f) with IIR method is given in this paper.Principle of the zero-phase digital filter is shown with simulation test using signal processing to sine wave.The difference equation with the same frequency characteristic as k(f) defined in IEC 60060-1 Ed.3.0,used to develop the software for measurement in impulse test is given.At last,the method is validated by processing several typical lightning impulses in TDG2.04 of IEC 61083-2 Ed.2.0: Instruments and software used for measurement in high-voltage impulse tests Part 2: requirements for software,which shows its feasibility and veracity.This provides an effective digital filtering technology to develop impulse test system.