Ratio metric current measurement

Abstract

The total current flow in a given electric circuit path is estimated by measuring the current in a second parallel current path and applying a ratio of the conductivity of the main and secondary path. Earth leakage current is measured by passing three wires through a toroid so as to detect differential current flow. Each wire is a conduction path wire parallel to each phase cable. The relative harmonic content between the fundamental and higher frequency components of a load current are calculated using a conduction path parallel to the main power cables.

Dependencies are inferred from the claim text.