How much “villain” is the anti-aliasing filter for traveling wave-based fault location methods?

Abstract

This paper analyzes the influence of anti-aliasing filters (AAFs) on traveling wave (TW)-based fault location (TWFL) methods. To do so, the Alternative Transients Program (ATP) is used to simulate several fault scenarios on a 230 kV/60 Hz test power system, allowing the assessment of AAFs influence when different TW filters and TWFL algorithms are used. The main goal is to clarify how much “villain” are the AAFs for TWFL methods if their cutoff frequencies are varied in noisy environments. By doing so, the most relevant spectrum band for TWFL solutions is investigated, addressing whether the application of AAFs with reduced cutoff frequencies would be critical or not. Although most people may think that the answer to this question is obvious, the obtained results show evidences that some solutions monitor transients within spectrum ranges wider than those they indeed require. Moreover, although AAFs can relevantly influence the performance of TWFL methods, it is proven that the application of AAFs with reduced cutoff frequencies is not necessarily critical, but rather, it depends on the used TW filters and TWFL methods, such that it can be beneficial when electrical noise is present in monitored signals.