Methods and devices for detecting a disconnection of a protective conductor connection

US10288664B2 · kind B2 · utility

Assignee

• Bender GmbH & Co. KG · DE

Inventors

• Dieter Hackl · Albach, DE
• Harald Sellner · Sankt Wendel, DE

Key dates

• Filing date: Feb 2, 2017
• Grant date: May 14, 2019
• Expiry date: Nov 6, 2037

Classification

• Technology area (CPC H): Electricity
• CPC primary: H02H3/33
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

The invention relates to a method and to an electrical protection device for detecting a disconnection of a protective conductor connection with a subsystem in ungrounded and grounded power supply systems and in a grounded power supply system comprising a converter system.The invention is based on the idea that the disconnection of the protective conductor connection with a subsystem will reduce the sum of the network leakage capacitances of the power supply system by the value of the network leakage capacitance of the subsystem. The necessary distinction between a subsystem in operation having a disconnected protective conductor connection and a shut-off subsystem is made by evaluating the current total power consumed via the power supply system. In the case of a converter system connected to the subsystem, the protective conductor disconnection is detected by examining the leakage current spectra that are characteristic of the converter system.