Couplers for on-line time domain reflectometry diagnostics of power cables

This paper investigates three types of couplers for sending and receiving a time domain reflectometry (TDR) signal to and from a cable, on-line. Transfer functions of the couplers were estimated and lumped element models were built. The couplers were placed on a power cable with high voltage (HV) terminations. Measurements were performed at a HV, simulating realistic conditions. In this cable, we investigated voltage pulse injection, propagation, and detection for different coupler topologies and HV terminations.