Abstract: A method generates a classification signal classifying an electrical impedance. The time characteristic of the impedance is measured resulting in impedance values. Impedance change vectors whose direction describes the movement of the impedance in the complex impedance plane and whose length describes the amount of the respective impedance change are formed with temporally successive impedance values. A check is carried out to determine whether the impedance shows a directional, continuous impedance movement. In the event of a subsequently detected change of direction of the impedance movement, the reaching of a reversal point is inferred and the rotation of the impedance change vectors is monitored with the result of a formation of an angle of rotation measured value. A classification signal indicating a fault is generated if the impedance change vectors have rotated in the area of the reversal point through a predefined maximum angle of rotation.

Abstract: A method for generating an error signal indicating an error type of an error in a multi-phase electrical energy supply network. Measured values describe a current operating state of the network. The measured values are transmitted to a protection device. An evaluating device evaluates every possible loop of the network that can be affected with respect to the recognition of the error type of an error, by using the measured values. In order to be able to more reliably recognize the error type even under different network conditions, the measured values and/or values derived from the measured values are evaluated using at least two different protection criteria, for every possible loop. Each of the protection criteria is suitable for indicating an error type of an error present in the evaluated loop, and the error signal is generated in consideration of all available evaluation results of the protection criteria.

Abstract: A method generates a classification signal classifying an electrical impedance. The time characteristic of the impedance is measured resulting in impedance values. Impedance change vectors whose direction describes the movement of the impedance in the complex impedance plane and whose length describes the amount of the respective impedance change are formed with temporally successive impedance values. A check is carried out to determine whether the impedance shows a directional, continuous impedance movement. In the event of a subsequently detected change of direction of the impedance movement, the reaching of a reversal point is inferred and the rotation of the impedance change vectors is monitored with the result of a formation of an angle of rotation measured value. A classification signal indicating a fault is generated if the impedance change vectors have rotated in the area of the reversal point through a predefined maximum angle of rotation.

Abstract: A method monitors a circuit breaker in an electrical power supply network, in which one section of the electrical power supply network is monitored in respect of the occurrence of a fault. Upon detection of a fault in the monitored section, a trigger signal is output to a circuit breaker bordering the section, and a switch-fault signal indicating a fault upon opening the circuit breaker is generated if a continuous current flow through the circuit breaker is detected after the trigger signal is output. In order to provide for a preferably rapid and reliable detection of a continuous current flow or an interruption of the current flow during the monitoring of a circuit breaker, it is provided that a curve shape of the time curve of the instantaneous current flowing through the circuit breaker is investigated in order to detect a continuous current flow.

Abstract: A method for generating an error signal indicating an error type of an error in a multi-phase electrical energy supply network. Measured values describe a current operating state of the network. The measured values are transmitted to a protection device. An evaluating device evaluates every possible loop of the network that can be affected with respect to the recognition of the error type of an error, by using the measured values. In order to be able to more reliably recognize the error type even under different network conditions, the measured values and/or values derived from the measured values are evaluated using at least two different protection criteria, for every possible loop. Each of the protection criteria is suitable for indicating an error type of an error present in the evaluated loop, and the error signal is generated in consideration of all available evaluation results of the protection criteria.

Abstract: A method monitors a circuit breaker in an electrical power supply network, in which one section of the electrical power supply network is monitored in respect of the occurrence of a fault. Upon detection of a fault in the monitored section, a trigger signal is output to a circuit breaker bordering the section, and a switch-fault signal indicating a fault upon opening the circuit breaker is generated if a continuous current flow through the circuit breaker is detected after the trigger signal is output. In order to provide for a preferably rapid and reliable detection of a continuous current flow or an interruption of the current flow during the monitoring of a circuit breaker, it is provided that a curve shape of the time curve of the instantaneous current flowing through the circuit breaker is investigated in order to detect a continuous current flow.

Abstract: A first protective device monitors a first section of a power supply network for a symmetrical short-circuit and a second protective device monitors a second section for a symmetrical short-circuit. The second protective device is a reserve protective device, which emits a shut-off command to a power switch after a time lag when a symmetrical short-circuit in the first section is recognized. An oscillation recognition unit emits an oscillating signal which blocks the shutoff command if an oscillation in the power supply network has been recognized. External symmetrical short-circuits can be disconnected independently of an occurring oscillation, when the second protective device has recognized a symmetrical short-circuit in the first section, before the oscillation recognition unit recognizes an oscillation in the power supply network, the shut-off command is emitted independently of the presence of an oscillating signal if the lag time has elapsed.

Abstract: A method for detecting a short circuit on a multiphase electrical energy supply network line includes recording current and voltage sampled values and generating a fault signal upon a fault evaluation performed by an electrical protection device indicating a short circuit. Instantaneous reference voltage values are calculated from instantaneous current and voltage sampled values recorded before the short, and instantaneous comparative voltage values are calculated from instantaneous current and voltage sampled values recorded before the short and instantaneous current and voltage sampled values recorded during the short, to generate a fault signal quickly. Then a rectified reference voltage value is calculated from consecutive instantaneous reference voltage values, and a rectified comparative voltage value is calculated from consecutive instantaneous comparative voltage values.

Abstract: A first protective device monitors a first section of a power supply network for a symmetrical short-circuit and a second protective device monitors a second section for a symmetrical short-circuit. The second protective device is a reserve protective device, which emits a shut-off command to a power switch after a time lag when a symmetrical short-circuit in the first section is recognized. An oscillation recognition unit emits an oscillating signal which blocks the shutoff command if an oscillation in the power supply network has been recognized. External symmetrical short-circuits can be disconnected independently of an occurring oscillation, when the second protective device has recognized a symmetrical short-circuit in the first section, before the oscillation recognition unit recognizes an oscillation in the power supply network, the shut-off command is emitted independently of the presence of an oscillating signal if the lag time has elapsed.

Abstract: A method and a protective device for monitoring a power supply line supplied at one end in a three-phase electrical power supply system with regard to the presence of a ground fault. The power supply line is connected, at the end thereof remote from the supply, to a transformer operated in a star-delta connection. When a coupling effect according to Bauch's paradox occurs, the ground fault is reliably and selectively disconnected by determining the phase currents in the individual phase conductors of the power supply line and the zero phase sequence system current at a measuring point which is at that end of the power supply line remote from the supply. A suspected ground fault signal is generated if the individual phase currents and the zero phase sequence system current are substantially of the same magnitude and are in phase. The suspected ground fault signal is used during further monitoring with regard to the presence of the ground fault.

Abstract: A method for detecting a short circuit on a multiphase electrical energy supply network line includes recording current and voltage sampled values and generating a fault signal upon a fault evaluation performed by an electrical protection device indicating a short circuit. Instantaneous reference voltage values are calculated from instantaneous current and voltage sampled values recorded before the short, and instantaneous comparative voltage values are calculated from instantaneous current and voltage sampled values recorded before the short and instantaneous current and voltage sampled values recorded during the short, to generate a fault signal quickly. Then a rectified reference voltage value is calculated from consecutive instantaneous reference voltage values, and a rectified comparative voltage value is calculated from consecutive instantaneous comparative voltage values.