Method and devices for determining the elements of a dielectric equivalent circuit diagram for an insulation of an electric system

US11169193B2 · kind B2 · utility

Assignee

• Bender GmbH & Co. KG · DE

Inventors

• Julian Reitz · Sankt Wendel, DE
• Eckhard Broeckmann · Gießen, DE

Key dates

• Filing date: Jan 30, 2020
• Grant date: Nov 9, 2021
• Expiry date: Jan 30, 2040

Classification

• Technology area (CPC G): Physics
• CPC primary: G01R31/52
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A method and a test apparatus for determining the elements of a dielectric equivalent circuit diagram for an insulation of an electric system and to an insulation monitoring device. All data points of the system's step response are stored for a measuring period Tm, and fault resistance Rf and an initial value Ce0 of leakage capacitance Ce are calculated. After this determination of fault resistance Rf and initial value Ce0, the elements of absorption element Ra and Ca and leakage capacitance Ce are determined by numeric signal processing by using an approximation algorithm which continuously simulates the recorded step response. For simulating the step response, a transfer function G(s) modelled by the equivalent circuit diagram having equivalent circuit diagram elements Rf, Ce, Ra, Ca and measurement resistance Rm is formed analytically and the output signal is calculated, which is described using transfer function G(s), by means of the step function.