METHOD FOR MONITORING THE ELECTRICAL POWER QUALITY IN AN ELECTRICAL POWER SUPPLY SYSTEM, POWER QUALITY FIELD DEVICE AND POWER QUALITY SYSTEM

摘要

- detection of a first measured value of a first power quality characteristic by means of a measuring device (11) of a power quality field device (10, 50) arranged at a measurement point of the electrical energy supply system at a first measurement time; - detection of a second measured value of the first power quality characteristic by means of the measuring device (11) at a second measurement time, which directly follows the first measurement time; -comparison of the first and the second measured value with at least one predetermined threshold value, and -generation of an event signal, which indicates an infringement of the at least one threshold value, precisely when one of the two measured values is above and one of the two measured values is below the at least one threshold value. The invention also relates to a power quality field device in which such a method is carried out as well as to a power quality system.