Performance analysis of the matched-pulse-based fault detection

International audienceThe problem of fault detection and location in wire networks has gained an increasing importance in the last few years [1]. Wired networks are found in all modern systems, and are used to transmit different signals (control, alarm, etc.). That is why the issue of safe and reliable wiring systems is among the primary concerns of researchers and government agencies today [2]. There are several methods for wire testing, such as visual inspection, impedance testing [1], and reflectometry methods which are widely used today to help detecting and locating wire faults. These methods send a predefined testing signal down the wire network to be examined. They include Time Domain Reflectometry (TDR), which uses a fast rise time step or pulsed signal as the testing signal, Frequency Domain Reflectometry [3] which uses multiple sinusoidal signals, sequence TDR [4] which uses pseudo noise, etc. Generally, hard faults (open and short circuits) are detectable through standard reflectometry, while soft faults (damaged insulation, etc.) are more critical to detect, especially when dealing with complex wire networks configurations. In [5], we introduced the Matched-Pulse approach (MP), based on the properties of Time Reversal [6], as an improvement of the existing standard TDR. The MP method proposes to adapt the testing signal to the network under test, instead of using a predefined testing signal, as opposed to reflectometry methods. We have shown that this method results in a higher echo energy from the fault to be detected, when compared to TDR. In this paper, we propose a sensitivity analysis of the MP approach, i.e., to evaluate the effect of the network topology (junctions, discontinuities, etc.) on the performance of this approach when compared to standard TDR. Through topological analysis, we will illustrate the role of different network elements governing the performances of both the TDR and MP. A mathematical analysis then follows in order to compare our approach to the TDR. The whole study will allow us to predict, for a given system configuration, to which extent the MP would be more beneficial compared to TDR, and state the configurations where our approach presents major advantages