US 9,316,678 B2Granted

Method and device for determining a maximum leakage current

AssigneeBender GmbH & Co. KG

InventorOliver Schaefer

Life of this patent

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Abstract

The invention relates to a method and a device for determining a maximum leakage current in unearthed power supply networks with a plurality of conductors. The method comprises the steps of: feeding of a measurement signal UP with a measurement frequency fpuls into a conductor arrangement, setting the measurement frequency fPuls, measuring a line-to-line voltage UL-E for each conductor, determining a maximum occurring line-to-line voltage UL-Emax from the measured line-to-line voltages UL-E, determining a voltage UZe across a measurement resistance RM for calculating a leakage impedance ZE, calculating the leakage impedance ZE, and calculating a maximum leakage current THC. The device comprises a signal generator for feeding in the UP with the fPuls, a network coupling circuit between the signal generator and the conductor arrangement, a voltage measuring circuit for measuring the UL-E, and an impedance measuring circuit for determining the Ze by means of the determining of the UZe.

Claims12

Dependent claims

A device for determining a maximum leakage current in unearthed power supply networks with a plurality of live conductors, wherein the device comprises:

(a) a signal generator for feeding in a measurement signal UP with a measurement frequency fPuls:
(b) a network coupling circuit disposed between the signal generator and a conductor arrangement formed in the unearthed power supply networks:
(c) a voltage measuring circuit for measuring line-to-line voltages UL-E;
(d) an impedance measuring circuit for determining the leakage impedance Ze by means of determining of a voltage UZe, wherein the voltage measuring circuit is connected at an input-side to the network coupling circuit and at an output-side via an analogue/digital converter to an arithmetic unit for digital signal processing, wherein the arithmetic unit has a data storage unit and also controls a display unit and a digital interface,
wherein
for setting the measurement frequency fPuls of the signal generator, a signal generator control apparatus, by means of which the measurement frequency fPuls is changeable during measurement, is connected to the signal generator, and the signal generator control apparatus forwards the measurement frequency fPuls determined in the arithmetic unit as a result of an interference frequency analysis.

3 more elements

Dependencies are inferred from the claim text.

Facts

Application: 14/262,053Filed 25 Apr 2014 · division
Priority: 16 Feb 2011
Published: US 2014/0312917 A123 Oct 2014
Granted: 19 Apr 2016
Term ends: Not estimatedThe source records don’t support an estimate.

Classification4 codes

G01R 27/18
Measuring impedance of element or network through which a current is passing from another source, e.g. cable, power line: measuring resistance to…
G01R 31/3008
Current or voltage test: quiescent current [IDDQ] test or leakage current test
G01R 31/52
Testing of electric apparatus, lines, cables or components for short-circuits, continuity, leakage current or incorrect line connections: testing…
G01R
Measuring electric variables

Family

Application13/028,798Parent of this division · filed 16 Feb 2011
US 2014/0312917 A1Pre-grant publication · published 23 Oct 2014
US 8,749,246 B2Parent of this division
US 2012/0206148 A1Published application
US 9,316,678 B2This patent

From the US filing history. Foreign family members aren’t listed.