Influences of a measuring cable over the lightning impulse parameters

Abstract

Influences of a co-axial measuring cable have been neglected in the lightning impulse measurements. This is partly because an allowable uncertainty for determining the front-time, T1, in the reference measuring system is 3% and the induced influence by using a long measuring cable is expected to be much smaller than the margin. The authors have so far suspected the validity of this argument through experience. This paper proposes analytical treatment of impulse response at the end of a lossy cable. Using the proposed expression measured parameter errors are compared to the numerically evaluated ones and it is to be confirmed that both are in good agreement. © 2008 The Institute of Electrical Engineers of Japan.