Patent ID: 8466691
Filing Date: 2013-06-18
Classification: G01R

Abstract:
1. A method for determining an insulation resistance of an electric DC circuit having at least a first terminal and a second terminal, the method comprising: (a) performing a measurement cycle comprising: (b) verifying that the change of the measured current does not exceed a predetermined change rate, using the current samples; (c) calculating a total insulation resistance from the first and second terminal voltage samples and the first and second high voltage samples of the measurement cycle and from resistance values of a measurement circuit; and (d) calculating a first insulation resistance between the first terminal and the reference potential and a second insulation resistance between the second terminal and the reference potential, each of the first and second insulation resistances being calculated from the total insulation resistance, the first and second terminal voltage samples and the first and second high voltage samples of the measurement cycle and from resistance values of the measurement circuit.