Measurement of Capacitance Using Spread Spectrum Time Domain Reflectometry (SSTDR) and Dictionary Matching

A SSTDR Methodology, Implementations, and Challenges

“…Reflectometry is a nondestructive technique to remotely detect, locate, and characterize useful information in physical systems. It has been used extensively in electrical systems to locate electrical “opens” or “shorts” [ 1 , 2 , 3 , 4 , 5 , 6 ], locate cable insulation break down [ 7 ], detect electrical system degradation [ 8 , 9 , 10 , 11 ], locate ground and arc faults [ 11 , 12 , 13 , 14 ], locate damaged components in photovoltaic (PV) systems [ 12 , 15 , 16 , 17 , 18 ], remotely measure complex impedance [ 17 , 19 , 20 , 21 , 22 ], locate intermittent faults that only occur during normal operation [ 3 , 4 , 8 , 23 , 24 , 25 , 26 ], and locate faults in three phase systems [ 27 ]. In material science, reflectometry has been used to characterize nanostructures, optical fiber networks, waveguides, and dielectrics [ 28 , 29 , 30 , 31 ].…”

“…Using the Fourier transform, time domain reflectometry methods can also be used to measure reflection, and hence impedance, similar to the VNA. TDR is regularly used for measuring soil moisture, and preliminary results have indicated the potential of SSTDR for measuring complex impedance [ 15 , 19 , 20 , 107 , 108 , 109 ].…”

“…These shapes provide information that represents the complex impedance, such as capacitance and inductance [ 22 ]. Advanced algorithms such as machine learning and dictionary matching techniques have been used to identify the complex loads [ 18 , 19 , 110 ].…”

“…This dictionary is then compared to measured data to determine the health of the system and location(s) of faults. The dictionary matching methods has been used to measure the capacitance of an end-terminated load [ 19 ] and disconnection fault location in a PV system [ 18 ].…”

Spread Spectrum Time Domain Reflectometry (Sstdr) Digital Twin Simulation of Photovoltaic Systems for Fault Detection and Location

“…Other reflectometry algorithms use simulations or measurements of faulted conditions to create a dictionary of possible conditions. This dictionary is compared with an unknown measurement to determine which fault type/location is most probable [16][17][18]. These types of algorithms work best when data can be included for every fault type and location possible.…”