Method and device for monitoring the insulation of ungrounded DC and AC voltage networks

US9069025B2 · kind B2 · utility

Assignee

• Bender GmbH & Co. KG · DE

Inventors

• Oliver Schaefer · Sankt Wendel, DE
• Karl Schepp · Kreuztal, DE

Key dates

• Filing date: Nov 28, 2011
• Grant date: Jun 30, 2015
• Expiry date: Dec 4, 2033

Classification

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

Abstract

The invention relates to a method and a device for monitoring the insulation of an ungrounded DC and/or AC voltage network. The method includes the following steps: (a) generating a measurement DC voltage Umess= that is connected to a ground on one side for a tvar; predeterminable measuring time frame tvar; (b) generating and superposing at least one measurement AC voltage Umess˜ connected to a ground and having a measurement duration tcons with the measurement DC voltage Umess− for forming a total measurement voltage Umess; (c) feeding the total measurement voltage Umess into the voltage network to be monitored; and (d) determining an insulating resistance R= from the measurement DC voltage Umess− and an insulating impedance Z from the measurement AC voltage Umess˜. The devise is configured to carry out the above method. The method and the device are suited in particular for monitoring the insulation in electric and hybrid vehicles.