Non-contact voltage monitoring of three-phase power cables

Abstract

Non-contact voltage monitoring involves continuously measuring conductor voltages without contacting the conductors. This thesis explores several methods of using parasitic capacitive coupling to monitor AC voltages in three-phase power cables. Using an existing sensor architecture, three-phase line voltages are accurately reconstructed through intrusive calibration techniques. Experimental results are presented for measuring 60 Hz line voltages using high-frequency calibration. This thesis also describes a new method of voltage monitoring, presenting a new circuit designed to monitor line-line voltages without requiring intrusive control of or injection onto the line voltages during calibration. Analysis and simulation of this system is shown, demonstrating accurate reconstruction for reasonably balanced line-line voltages.