Patent ID: 7049825
Filing Date: 2006-05-23
Classification: G01R

Abstract:
1. A method for sensing isolation faults in a system including a direct-voltage power supply, which direct-voltage power supply nominally floats relative to a reference conductor, and in which the system also includes a load, a first terminal of which load is connected to a first terminal of said direct voltage power supply, said method comprising the steps of: coupling to a node, by a resistive coupling path having an equivalent resistance, a fixed proportion of the direct voltage of said direct-voltage power supply, said node being connected by a measuring path to said reference conductor; measuring a first current flowing in said measuring path at a first, time; measuring a first voltage applied to said load at said first time; measuring a second current flowing in said measuring path at a second time different from said first time; measuring a second voltage applied to said load at said second time; at a time between said first and second times, coupling a second terminal of said direct-voltage power supply to a second terminal of said load, for energization thereof; and determining, from said equivalent resistance, and said first and second voltages and currents, at least one of fault voltage and resistance.