Differential protective method
First Claim
1. A method for generating an error signal that characterizes a fault current in an electric conductor (130) having at least two conductor ends (120, 123, 126, 129), and conducting an alternating current and having charge measuring devices (100, 103, 106, 109) that are connected to one another via data lines (112), and of which respectively one is fitted at each end of the conductor, in which method the charge measuring devices are used to measure measured charge values that in each case specify the charge quantity flowing through the respective conductor end during a prescribed measuring period, a total measured charge value is formed by addition with the aid of the measured charge values taking account of the direction of the flow of charge, and the error signal is generated when the total measured charge value exceeds in absolute terms a threshold value set as a function of the respective magnitude of the alternating current, characterized in that the measurement of the measured charge values is carried out in a time-synchronized fashion and is repeated regularly in such a way that the time interval between two sequential measurements is smaller in each case than the prescribed measuring period.
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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 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. According to the invention, the measured charge values are determined synchronously and determined repeatedly at regular intervals in such a way that the time interval between each sequential determination is smaller than the predefined measuring period.
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Citations
8 Claims
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1. A method for generating an error signal that characterizes a fault current in an electric conductor (130) having at least two conductor ends (120, 123, 126, 129), and conducting an alternating current and having charge measuring devices (100, 103, 106, 109) that are connected to one another via data lines (112), and of which respectively one is fitted at each end of the conductor, in which method
the charge measuring devices are used to measure measured charge values that in each case specify the charge quantity flowing through the respective conductor end during a prescribed measuring period, a total measured charge value is formed by addition with the aid of the measured charge values taking account of the direction of the flow of charge, and the error signal is generated when the total measured charge value exceeds in absolute terms a threshold value set as a function of the respective magnitude of the alternating current, characterized in that the measurement of the measured charge values is carried out in a time-synchronized fashion and is repeated regularly in such a way that the time interval between two sequential measurements is smaller in each case than the prescribed measuring period.
Specification