Abstract: A measuring arrangement acquires signals of alternating electrical magnitudes. A sampling apparatus performs a sampling of the signals to form digital sample values. A clock tracking apparatus adapts a sampling clock used by the sampling apparatus in the light of the frequency of the signal to be sampled. In order to be able to acquire reliably signals of alternating electrical magnitudes even when they have different frequencies, the sampling apparatus samples at least two of the signals each with its own sampling clock and the clock tracking apparatus adapts the sampling clock in the light of the frequency of the signal to be sampled simultaneously for each of these at least two signals. There is also described a corresponding method for measuring electrical signals.

Abstract: An electrical operating device includes measuring equipment for an electrical measured variable, and preprocessing equipment for digital measured values. The preprocessing equipment has an integrated circuit and an electronic memory component for configuring a logic circuit. A processor evaluates preprocessed measurement data and, on the basis of the evaluation, transmits data telegrams to other electrical operating devices. The preprocessing equipment calculates a respective checksum for a digital measured value, and the processor recognizes a malfunction from the measured value and the checksum of the measured value, and suppresses the evaluation and/or the transmission of the data telegrams in the event of a malfunction. There is also described a method for recognizing malfunctions.

Abstract: A differential protection method for generating a fault signal. Current measurement values are acquired at different measuring points of a component. Differential current values and stabilizing values are formed using the current measurement values, and the fault signal is generated when a tripping range test indicates that a measured value pair formed from one of the differential current values and a respective associated stabilizing value lies in a predetermined tripping range. Differential current values are estimated from successive differential current values and associated stabilizing values and associated estimated stabilizing values are formed. A value of an expected future trend of the differential current values and of the stabilizing current values is estimated. A tripping range test finds the position of a measured value pair formed from an estimated differential current value and the respective associated estimated stabilizing value.

Abstract: A method for controlling a value of a voltage at a conductor to which at least one secondary winding of a first steppable transformer and a secondary winding of a second steppable transformer are connected is provided. The method includes: if a voltage deviation of the voltage at the conductor from a voltage setpoint value is within a first range around the voltage setpoint value, and if an overall deviation of a sum of the voltage deviation and a reactive current deviation from the voltage setpoint value respectively for the first and the second transformer is outside of a second range, which is larger than the first, around the voltage setpoint value: setting a delay time for stepping the first transformer and/or the second transformer in such a way that stepping of the first or the second transformer that counteracts the voltage deviation is prioritized.

Abstract: A differential protection method for generating a fault signal includes measuring current measurements at least at two different measuring points of a multiphase transformer for each phase. The current measurements for each phase are used to form differential current values and stabilization values. The fault signal is generated if it is determined during a trigger region check that a measurement pair of at least one of the phases, being formed by using one of the differential current values and the associated stabilization value in each case, is in a predefined trigger region. In order to be able to selectively and reliably distinguish an external fault from an internal fault, the transformer has a grounded star point and a zero system current flowing through the star point is used to form the stabilization values. A corresponding differential protection device is provided for performing the differential protection method.

Abstract: A measuring arrangement acquires signals of alternating electrical magnitudes. A sampling apparatus performs a sampling of the signals to form digital sample values. A clock tracking apparatus adapts a sampling clock used by the sampling apparatus in the light of the frequency of the signal to be sampled. In order to be able to acquire reliably signals of alternating electrical magnitudes even when they have different frequencies, the sampling apparatus samples at least two of the signals each with its own sampling clock and the clock tracking apparatus adapts the sampling clock in the light of the frequency of the signal to be sampled simultaneously for each of these at least two signals. There is also described a corresponding method for measuring electrical signals.

Abstract: A method for controlling a value of a voltage at a conductor to which at least one secondary winding of a first steppable transformer and a secondary winding of a second steppable transformer are connected is provided. The method includes: if a voltage deviation of the voltage at the conductor from a voltage setpoint value is within a first range around the voltage setpoint value, and if an overall deviation of a sum of the voltage deviation and a reactive current deviation from the voltage setpoint value respectively for the first and the second transformer is outside of a second range, which is larger than the first, around the voltage setpoint value: setting a delay time for stepping the first transformer and/or the second transformer in such a way that stepping of the first or the second transformer that counteracts the voltage deviation is prioritized.

Abstract: A differential protection method for generating a fault signal includes measuring current measurements at least at two different measuring points of a multiphase transformer for each phase. The current measurements for each phase are used to form differential current values and stabilization values. The fault signal is generated if it is determined during a trigger region check that a measurement pair of at least one of the phases, being formed by using one of the differential current values and the associated stabilization value in each case, is in a predefined trigger region. In order to be able to selectively and reliably distinguish an external fault from an internal fault, the transformer has a grounded star point and a zero system current flowing through the star point is used to form the stabilization values. A corresponding differential protection device is provided for performing the differential protection method.

Abstract: A differential protection method for generating a fault signal. Current measurement values are acquired at different measuring points of a component. Differential current values and stabilizing values are formed using the current measurement values, and the fault signal is generated when a tripping range test indicates that a measured value pair formed from one of the differential current values and the respective associated stabilizing value lies in a predetermined tripping range. Differential current values are estimated from successive differential current values and associated stabilizing values and associated estimated stabilizing values are formed. A value of an expected future trend of the differential current values and of the stabilizing current values is estimated. A tripping range test finds the position of a measured value pair formed from an estimated differential current value and the respective associated estimated stabilizing value.