Method for Production of a Data Record and a Field Device, as Well as a System for Recording the Electrical Power Quality of a Power Supply System

A method of producing a data record indicating a deviation of alternating current and/or AC voltage values at a measurement point in a power supply system from an expected time profile, the method which comprises:

• recording measured values indicating the alternating current and/or AC voltage values at the measurement point in the power supply system;
• if the measured values differ from the expected time profile, generating an event signal;
• if an event signal is present, determining a parameter set of state parameters describing a state of the power supply system at the measurement point) from the measured values and from further measured values following the measured values during a predetermined measurement period, and associating at least some of the state parameters in the parameter set with an associated cause character string indicating a cause of the deviation;
• and
• generating the data record from at least the parameter set and the cause character string.

A field device for recording the electrical power quality at a measurement point in a power supply system, comprising:

• a measurement device for recording measured values indicating an alternating current and/or an AC voltage;
• an event identification device configured to receive and use the measured values to identify a deviation of the alternating current and/or the AC voltage from an expected profile;
• a parameter calculation device for determining a parameter set of state parameters from the measured values and from further measured values following the measured values during a predeterminable measurement period, the state parameters indicating a state of the power supply system at the measurement point;
• a cause identification unit configured to allocate a cause character string, indicating a cause of the deviation, when a discrepancy of the parameter set exists;
• and
• an output unit for outputting a data record formed taking into account at least some of the state parameters in the parameter set and the cause character string.