Fault detection and location in power distribution systems: The usefulness of the HS-OFDM scheme for time-domain reflectometry

•Formulation of a HS-OFDM-based TDR system for power line fault sensing.•Comparative analysis between pulse compression and channel estimation.•HS-OFDM-based TDR system parametrization and limitations.•Discussion on multiple access schemes for distributed fault sensing. This study discusses key characteristics and benefits of using time-domain reflectometry (TDR) systems based on the Hermitian symmetric orthogonal frequency-division multiplexing (HS-OFDM) scheme for fault detection and location in power distribution networks. In this context, a system model with power line modems injecting signals and capturing reflections in a power distribution network is outlined. Next, two reflectogram processing approaches, namely digital pulse compression and channel estimation, are examined. Also, the effects of different parametrizations and multiple access schemes on the performance of the HS-OFDM-based TDR system are addressed. Numerical results confirm that HS-OFDM-based TDR systems making using of channel estimation outperforms their counterparts based on pulse compression. The frequency range for narrowband power line communication provides fair range resolution and maximum unambiguous range values. Also, it is seen that the use of frequency-division multiple access schemes implies different signal-to-interference-plus-noise ratio (SINR) performance among different power line modems (PLMs) connected to a power distribution network. Time-division and code-division multiple access schemes, on the other hand, provide fair SINR performance among the PLMs at the cost of obtaining a small number of reflectograms during a time interval.