The development of a digital sampling system for low power factor measurements of high-voltage capacitive/inductive reactors

A digital sampling system for high-accuracy low power factor measurements of high-voltage capacitive/inductive reactors is described in this paper. The system measures these reactors with respect to a known reference providing reactance ratio and phase difference. It is suitable for automation and offers a number of advantages with respect to current-comparator-based bridges: faster operation, since no balancing is required, and operation in the presence of noise, harmonics, and power-line voltage and frequency fluctuations. Yet it retains high accuracy with an estimated relative uncertainty of less than 40/spl middot/10/sup -6/ in magnitude and 40 /spl mu/rad in phase under real high-voltage or high-current conditions.