High-Resistance fault prelocating using Arc Reflection Method (ARM)

  Arc Reflection Method (ARM)

Localization of the cable faults with a high transient resistance (R>10 kOhm) is usually difficult when using low-voltage TDR method. One of the ways for localization such defects in power cables is an Arc Reflection Method (ARM).

Implementation of ARM method is carried out with the additional equipment: high-voltage pulse generator (HVPG) and the special connecting device (as an external unit or internal HVPG unit).

The essence of the ARM method is in creating conditions (using HPVG)  for the occurrence electric arc (breakdown)  for a short time (few milliseconds) in the point of the fault. Synchronously with the burning arc (sync signal obtained from HPVG) reflectometer performs sensing. The TDR’s probe pulse is reflected from a low resistance of the arc with inverted polarity (like shorted circuit).

For easy identification of the fault location, waveform without breakdown (high transient resistance at the point of the defect) and waveform during breakdown (low transient resistance at the point of the defect) are compared.

Video

TDR RI-407 & ADG-200-2 Part 1 Overview, Low-Resistance cable fault prelocating with TDR

РTDR RI-407 & ADG-200-2 Part 2 High-Resistance cable fault prelocating with ARM, ICM

TDR method example (short spark gap at the end of the cable line)

Arc Reflection Method (ARM) – breakdown at the spark gap at the end of the cable line

Arc Reflection Method (ARM) – breakdown at the spark gap at the end of the cable line, (accelerated shooting 400 frames / sec)