US 2003/0076112 A1 · Differential protective method

Abstract

The invention relates to a method for generating an error signal which characterizes a fault current in an electrical conductor (130) provided with two conductor ends (120, 123, 126, 129) and comprising charge measuring devices (100, 103, 106, 109) which are connected to each other by data lines (112). At least one device is attached to each end of the conductor. In the inventive method, charge measuring values are determined using charge measuring devices. The measured charge values take into account the direction of the charge flow and a total measured charge value is formed by addition. Said error signal is generated when the total measured charge value exceeds a certain threshold value. In order to be able to detect errors in amore sensitive manner than had previously been possible, the threshold value is formed by taking into account the individual measuring tolerance of the individual charge measuring devices.

Claims14

Dependent claims

A method for producing a fault signal which characterizes a fault current in an electrical conductor (130) having at least two conductor ends (120, 123, 126, 129), with charge measurement devices (100, 103, 106, 109) which are connected to one another via data lines (112) and of which one is in each case fitted to each conductor end of the conductor with, in the case of the method,

the charge measurement devices being used to measure charge measurement values which each indicate the amount of charge which has flowed through the respective conductor end during a predetermined measurement duration,
the charge measurement values being used to form an overall charge measurement value, taking account of the direction of the charge flow by addition, and
the fault signal being produced if the magnitude of the overall charge measurement value exceeds a threshold value which is set as a function of the respective magnitude of the alternating current,
characterized in that
the threshold value is formed by addition of weighted charge measurement values to the individual measurement tolerance of the individual charge measurement devices.

2 more elements

Dependencies are inferred from the claim text.

Differential protective method

Life of this patent

Differential protective method

Life of this patent

Abstract

Claims14